* [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg
@ 2021-08-07 22:05 Pedro Falcato
2021-08-07 22:05 ` [Patch v2 1/3] Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni Pedro Falcato
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: Pedro Falcato @ 2021-08-07 22:05 UTC (permalink / raw)
To: devel; +Cc: Pedro Falcato, Leif Lindholm, Michael D Kinney, Bret Barkelew
This patch-set adds Ext4Pkg, a package designed to hold various drivers and
utilities related to the EXT4 filesystem.
Right now, it holds a single read-only UEFI EXT4 driver (Ext4Dxe), which consumes the
DISK_IO, BLOCK_IO and DISK_IO2 protocols and produce EFI_FILE_PROTOCOL and
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL; this driver allows the mounting of EXT4 partitions and
the reading of their contents.
Relevant RFC discussion, which includes a more in-depth walkthrough of EXT4 internals and
driver limitations is available at https://edk2.groups.io/g/devel/topic/84368561.
This patch set is version 2 and attempts to address issues raised by the
community in v1's code review.
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Pedro Falcato (3):
Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni.
Ext4Pkg: Add Ext4Dxe driver.
Ext4Pkg: Add .DSC file.
Features/Ext4Pkg/Ext4Dxe/BlockGroup.c | 207 +++++
Features/Ext4Pkg/Ext4Dxe/Collation.c | 171 ++++
Features/Ext4Pkg/Ext4Dxe/Crc16.c | 74 ++
Features/Ext4Pkg/Ext4Dxe/Crc32c.c | 83 ++
Features/Ext4Pkg/Ext4Dxe/Directory.c | 513 +++++++++++
Features/Ext4Pkg/Ext4Dxe/DiskUtil.c | 106 +++
Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h | 455 ++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c | 789 +++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h | 1136 +++++++++++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf | 149 ++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni | 15 +
Features/Ext4Pkg/Ext4Dxe/Extents.c | 618 ++++++++++++++
Features/Ext4Pkg/Ext4Dxe/File.c | 786 +++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Inode.c | 467 ++++++++++
Features/Ext4Pkg/Ext4Dxe/Partition.c | 122 +++
Features/Ext4Pkg/Ext4Dxe/Superblock.c | 281 ++++++
Features/Ext4Pkg/Ext4Pkg.dec | 17 +
Features/Ext4Pkg/Ext4Pkg.dsc | 68 ++
Features/Ext4Pkg/Ext4Pkg.uni | 14 +
19 files changed, 6071 insertions(+)
create mode 100644 Features/Ext4Pkg/Ext4Dxe/BlockGroup.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Collation.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc16.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc32c.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Directory.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Extents.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/File.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Inode.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Partition.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Superblock.c
create mode 100644 Features/Ext4Pkg/Ext4Pkg.dec
create mode 100644 Features/Ext4Pkg/Ext4Pkg.dsc
create mode 100644 Features/Ext4Pkg/Ext4Pkg.uni
--
2.32.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Patch v2 1/3] Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni.
2021-08-07 22:05 [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Pedro Falcato
@ 2021-08-07 22:05 ` Pedro Falcato
2021-08-07 22:05 ` [Patch v2 2/3] Ext4Pkg: Add Ext4Dxe driver Pedro Falcato
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Pedro Falcato @ 2021-08-07 22:05 UTC (permalink / raw)
To: devel; +Cc: Pedro Falcato, Leif Lindholm, Michael D Kinney, Bret Barkelew
These files are needed to build Ext4Pkg.
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
---
Features/Ext4Pkg/Ext4Pkg.dec | 17 +++++++++++++++++
Features/Ext4Pkg/Ext4Pkg.uni | 14 ++++++++++++++
2 files changed, 31 insertions(+)
create mode 100644 Features/Ext4Pkg/Ext4Pkg.dec
create mode 100644 Features/Ext4Pkg/Ext4Pkg.uni
diff --git a/Features/Ext4Pkg/Ext4Pkg.dec b/Features/Ext4Pkg/Ext4Pkg.dec
new file mode 100644
index 0000000000..f1f8b39c3c
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Pkg.dec
@@ -0,0 +1,17 @@
+## @file
+# Ext4 Package
+#
+# This package provides libraries and drivers related to the ext4 filesystem implementation.
+# More details are available at: https://www.kernel.org/doc/html/v5.4/filesystems/ext4/index.html
+#
+# Copyright (c) 2021 Pedro Falcato
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+ DEC_SPECIFICATION = 0x00010005
+ PACKAGE_NAME = Ext4Pkg
+ PACKAGE_UNI_FILE = Ext4Pkg.uni
+ PACKAGE_GUID = 6B4BF998-668B-46D3-BCFA-971F99F8708C
+ PACKAGE_VERSION = 0.1
diff --git a/Features/Ext4Pkg/Ext4Pkg.uni b/Features/Ext4Pkg/Ext4Pkg.uni
new file mode 100644
index 0000000000..abeadd8fd9
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Pkg.uni
@@ -0,0 +1,14 @@
+## @file
+# Ext4 Package
+#
+# This package provides libraries and drivers related to the ext4 filesystem implementation.
+# More details are available at: https://www.kernel.org/doc/html/v5.4/filesystems/ext4/index.html
+#
+# Copyright (c) 2021 Pedro Falcato
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+#string STR_PACKAGE_ABSTRACT #language en-US "Module implementations for the EXT4 file system"
+
+#string STR_PACKAGE_DESCRIPTION #language en-US "This package contains UEFI drivers and libraries for the EXT4 file system."
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Patch v2 2/3] Ext4Pkg: Add Ext4Dxe driver.
2021-08-07 22:05 [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Pedro Falcato
2021-08-07 22:05 ` [Patch v2 1/3] Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni Pedro Falcato
@ 2021-08-07 22:05 ` Pedro Falcato
2021-08-07 22:05 ` [Patch v2 3/3] Ext4Pkg: Add .DSC file Pedro Falcato
2021-08-11 16:43 ` [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Michael D Kinney
3 siblings, 0 replies; 5+ messages in thread
From: Pedro Falcato @ 2021-08-07 22:05 UTC (permalink / raw)
To: devel; +Cc: Pedro Falcato, Leif Lindholm, Michael D Kinney, Bret Barkelew
Adds a UEFI EXT4 filesystem driver that implements the EFI_FILE_PROTOCOL
and EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
---
Features/Ext4Pkg/Ext4Dxe/BlockGroup.c | 207 +++++
Features/Ext4Pkg/Ext4Dxe/Collation.c | 171 ++++
Features/Ext4Pkg/Ext4Dxe/Crc16.c | 74 ++
Features/Ext4Pkg/Ext4Dxe/Crc32c.c | 83 ++
Features/Ext4Pkg/Ext4Dxe/Directory.c | 513 +++++++++++
Features/Ext4Pkg/Ext4Dxe/DiskUtil.c | 106 +++
Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h | 455 ++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c | 789 +++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h | 1136 +++++++++++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf | 149 ++++
Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni | 15 +
Features/Ext4Pkg/Ext4Dxe/Extents.c | 618 ++++++++++++++
Features/Ext4Pkg/Ext4Dxe/File.c | 786 +++++++++++++++++
Features/Ext4Pkg/Ext4Dxe/Inode.c | 467 ++++++++++
Features/Ext4Pkg/Ext4Dxe/Partition.c | 122 +++
Features/Ext4Pkg/Ext4Dxe/Superblock.c | 281 ++++++
16 files changed, 5972 insertions(+)
create mode 100644 Features/Ext4Pkg/Ext4Dxe/BlockGroup.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Collation.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc16.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc32c.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Directory.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Extents.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/File.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Inode.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Partition.c
create mode 100644 Features/Ext4Pkg/Ext4Dxe/Superblock.c
diff --git a/Features/Ext4Pkg/Ext4Dxe/BlockGroup.c b/Features/Ext4Pkg/Ext4Dxe/BlockGroup.c
new file mode 100644
index 0000000000..87607ed27a
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/BlockGroup.c
@@ -0,0 +1,207 @@
+/** @file Block group related routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ Copyright (c) 2007 - 2018, Intel Corporation. All rights reserved.<BR>
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+/**
+ Reads an inode from disk.
+
+ @param[in] Partition Pointer to the opened partition.
+ @param[in] InodeNum Number of the desired Inode
+ @param[out] OutIno Pointer to where it will be stored a pointer to the read inode.
+
+ @return Status of the inode read.
+**/
+EFI_STATUS
+Ext4ReadInode (
+ IN EXT4_PARTITION *Partition, IN EXT4_INO_NR InodeNum, OUT EXT4_INODE **OutIno
+ )
+{
+ UINT64 InodeOffset;
+ UINT32 BlockGroupNumber;
+ EXT4_INODE *Inode;
+ EXT4_BLOCK_GROUP_DESC *BlockGroup;
+ EXT4_BLOCK_NR InodeTableStart;
+ EFI_STATUS Status;
+
+ BlockGroupNumber = (UINT32)DivU64x64Remainder (
+ InodeNum - 1,
+ Partition->SuperBlock.s_inodes_per_group,
+ &InodeOffset
+ );
+
+ // Check for the block group number's correctness
+ if (BlockGroupNumber >= Partition->NumberBlockGroups) {
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ Inode = Ext4AllocateInode (Partition);
+
+ if (Inode == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ BlockGroup = Ext4GetBlockGroupDesc (Partition, BlockGroupNumber);
+
+ // Note: We'll need to check INODE_UNINIT and friends when we add write support
+
+ InodeTableStart = Ext4MakeBlockNumberFromHalfs (
+ Partition,
+ BlockGroup->bg_inode_table_lo,
+ BlockGroup->bg_inode_table_hi
+ );
+
+ Status = Ext4ReadDiskIo (
+ Partition,
+ Inode,
+ Partition->InodeSize,
+ Ext4BlockToByteOffset (Partition, InodeTableStart) + MultU64x32 (InodeOffset, Partition->InodeSize)
+ );
+
+ if (EFI_ERROR (Status)) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "[ext4] Error reading inode: status %x; inode offset %lx"
+ " inode table start %lu block group %lu\n",
+ Status,
+ InodeOffset,
+ InodeTableStart,
+ BlockGroupNumber
+ ));
+ FreePool (Inode);
+ return Status;
+ }
+
+ if (!Ext4CheckInodeChecksum (Partition, Inode, InodeNum)) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "[ext4] Inode %llu has invalid checksum (calculated %x)\n",
+ InodeNum,
+ Ext4CalculateInodeChecksum (Partition, Inode, InodeNum)
+ ));
+ FreePool (Inode);
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ *OutIno = Inode;
+ return EFI_SUCCESS;
+}
+
+/**
+ Calculates the checksum of the block group descriptor for METADATA_CSUM enabled filesystems.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return The checksum.
+**/
+STATIC
+UINT16
+Ext4CalculateBlockGroupDescChecksumMetadataCsum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ )
+{
+ UINT32 Csum;
+ UINT16 Dummy;
+
+ Dummy = 0;
+
+ Csum = Ext4CalculateChecksum (Partition, &BlockGroupNum, sizeof (BlockGroupNum), Partition->InitialSeed);
+ Csum = Ext4CalculateChecksum (Partition, BlockGroupDesc, OFFSET_OF (EXT4_BLOCK_GROUP_DESC, bg_checksum), Csum);
+ Csum = Ext4CalculateChecksum (Partition, &Dummy, sizeof (Dummy), Csum);
+ Csum =
+ Ext4CalculateChecksum (
+ Partition,
+ &BlockGroupDesc->bg_block_bitmap_hi,
+ Partition->DescSize - OFFSET_OF (EXT4_BLOCK_GROUP_DESC, bg_block_bitmap_hi),
+ Csum
+ );
+ return (UINT16)Csum;
+}
+
+/**
+ Calculates the checksum of the block group descriptor for GDT_CSUM enabled filesystems.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return The checksum.
+**/
+STATIC
+UINT16
+Ext4CalculateBlockGroupDescChecksumGdtCsum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ )
+{
+ UINT16 Csum;
+ UINT16 Dummy;
+
+ Dummy = 0;
+
+ Csum = CalculateCrc16 (Partition->SuperBlock.s_uuid, 16, 0);
+ Csum = CalculateCrc16 (&BlockGroupNum, sizeof (BlockGroupNum), Csum);
+ Csum = CalculateCrc16 (BlockGroupDesc, OFFSET_OF (EXT4_BLOCK_GROUP_DESC, bg_checksum), Csum);
+ Csum = CalculateCrc16 (&Dummy, sizeof (Dummy), Csum);
+ Csum =
+ CalculateCrc16 (
+ &BlockGroupDesc->bg_block_bitmap_hi,
+ Partition->DescSize - OFFSET_OF (EXT4_BLOCK_GROUP_DESC, bg_block_bitmap_hi),
+ Csum
+ );
+ return Csum;
+}
+
+/**
+ Checks if the checksum of the block group descriptor is correct.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return TRUE if checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4VerifyBlockGroupDescChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ )
+{
+ if(!Ext4HasMetadataCsum (Partition) && !Ext4HasGdtCsum (Partition)) {
+ return TRUE;
+ }
+
+ return Ext4CalculateBlockGroupDescChecksum (Partition, BlockGroupDesc, BlockGroupNum) == BlockGroupDesc->bg_checksum;
+}
+
+/**
+ Calculates the checksum of the block group descriptor.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return The checksum.
+**/
+UINT16
+Ext4CalculateBlockGroupDescChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ )
+{
+ if(Partition->FeaturesRoCompat & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM) {
+ return Ext4CalculateBlockGroupDescChecksumMetadataCsum (Partition, BlockGroupDesc, BlockGroupNum);
+ } else if(Partition->FeaturesRoCompat & EXT4_FEATURE_RO_COMPAT_GDT_CSUM) {
+ return Ext4CalculateBlockGroupDescChecksumGdtCsum (Partition, BlockGroupDesc, BlockGroupNum);
+ }
+
+ return 0;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Collation.c b/Features/Ext4Pkg/Ext4Dxe/Collation.c
new file mode 100644
index 0000000000..1011fc3834
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Collation.c
@@ -0,0 +1,171 @@
+/** @file Unicode collation routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ Copyright (c) 2005 - 2017, Intel Corporation. All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi.h>
+
+#include <Library/UefiLib.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/MemoryAllocationLib.h>
+
+#include <Protocol/UnicodeCollation.h>
+
+STATIC EFI_UNICODE_COLLATION_PROTOCOL *gUnicodeCollationInterface = NULL;
+
+/*
+ * Note: This code is heavily based on FatPkg's Unicode collation, since they seem to know what
+ * they're doing.
+ * PS: Maybe all this code could be put in a library? It looks heavily shareable.
+**/
+
+/**
+ Worker function to initialize Unicode Collation support.
+
+ It tries to locate Unicode Collation (2) protocol and matches it with current
+ platform language code.
+
+ @param DriverHandle The handle used to open Unicode Collation (2) protocol.
+ @param ProtocolGuid The pointer to Unicode Collation (2) protocol GUID.
+ @param VariableName The name of the RFC 4646 or ISO 639-2 language variable.
+ @param DefaultLanguage The default language in case the RFC 4646 or ISO 639-2 language is absent.
+
+ @retval EFI_SUCCESS The Unicode Collation (2) protocol has been successfully located.
+ @retval Others The Unicode Collation (2) protocol has not been located.
+
+**/
+STATIC
+EFI_STATUS
+Ext4InitialiseUnicodeCollationInternal (
+ IN EFI_HANDLE DriverHandle,
+ IN EFI_GUID *ProtocolGuid,
+ IN CONST CHAR16 *VariableName,
+ IN CONST CHAR8 *DefaultLanguage
+ )
+{
+ UINTN NumHandles;
+ EFI_HANDLE *Handles;
+ EFI_UNICODE_COLLATION_PROTOCOL *Uci;
+ BOOLEAN Iso639Language;
+ CHAR8 *Language;
+ EFI_STATUS RetStatus;
+ EFI_STATUS Status;
+ UINTN i;
+
+ Iso639Language = (BOOLEAN)(ProtocolGuid == &gEfiUnicodeCollationProtocolGuid);
+ RetStatus = EFI_UNSUPPORTED;
+ GetEfiGlobalVariable2 (VariableName, (VOID **)&Language, NULL);
+
+ Status = gBS->LocateHandleBuffer (
+ ByProtocol,
+ ProtocolGuid,
+ NULL,
+ &NumHandles,
+ &Handles
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ for(i = 0; i < NumHandles; i++) {
+ Status = gBS->OpenProtocol (
+ Handles[i],
+ ProtocolGuid,
+ (VOID **)&Uci,
+ DriverHandle,
+ NULL,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+
+ if(EFI_ERROR (Status)) {
+ continue;
+ }
+
+ CHAR8 *BestLanguage = GetBestLanguage (
+ Uci->SupportedLanguages,
+ Iso639Language,
+ (Language == NULL) ? "" : Language,
+ DefaultLanguage,
+ NULL
+ );
+ if (BestLanguage != NULL) {
+ FreePool (BestLanguage);
+ gUnicodeCollationInterface = Uci;
+ RetStatus = EFI_SUCCESS;
+ break;
+ }
+ }
+
+ if (Language != NULL) {
+ FreePool (Language);
+ }
+
+ FreePool (Handles);
+ return RetStatus;
+}
+
+/**
+ Initialises Unicode collation, which is needed for case-insensitive string comparisons
+ within the driver (a good example of an application of this is filename comparison).
+
+ @param[in] DriverHandle Handle to the driver image.
+
+ @retval EFI_SUCCESS Unicode collation was successfully initialised.
+ @retval !EFI_SUCCESS Failure.
+**/
+EFI_STATUS
+Ext4InitialiseUnicodeCollation (
+ EFI_HANDLE DriverHandle
+ )
+{
+ EFI_STATUS Status;
+
+ Status = EFI_UNSUPPORTED;
+
+ //
+ // First try to use RFC 4646 Unicode Collation 2 Protocol.
+ //
+ Status = Ext4InitialiseUnicodeCollationInternal (
+ DriverHandle,
+ &gEfiUnicodeCollation2ProtocolGuid,
+ L"PlatformLang",
+ (CONST CHAR8 *)PcdGetPtr (PcdUefiVariableDefaultPlatformLang)
+ );
+ //
+ // If the attempt to use Unicode Collation 2 Protocol fails, then we fall back
+ // on the ISO 639-2 Unicode Collation Protocol.
+ //
+ if (EFI_ERROR (Status)) {
+ Status = Ext4InitialiseUnicodeCollationInternal (
+ DriverHandle,
+ &gEfiUnicodeCollationProtocolGuid,
+ L"Lang",
+ (CONST CHAR8 *)PcdGetPtr (PcdUefiVariableDefaultLang)
+ );
+ }
+
+ return Status;
+}
+
+/**
+ Does a case-insensitive string comparison. Refer to EFI_UNICODE_COLLATION_PROTOCOL's StriColl
+ for more details.
+
+ @param[in] Str1 Pointer to a null terminated string.
+ @param[in] Str2 Pointer to a null terminated string.
+
+ @retval 0 Str1 is equivalent to Str2.
+ @retval >0 Str1 is lexically greater than Str2.
+ @retval <0 Str1 is lexically less than Str2.
+**/
+INTN
+Ext4StrCmpInsensitive (
+ IN CHAR16 *Str1,
+ IN CHAR16 *Str2
+ )
+{
+ return gUnicodeCollationInterface->StriColl (gUnicodeCollationInterface, Str1, Str2);
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Crc16.c b/Features/Ext4Pkg/Ext4Dxe/Crc16.c
new file mode 100644
index 0000000000..4f900f3607
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Crc16.c
@@ -0,0 +1,74 @@
+/** @file CRC16 calculation routines.
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi.h>
+
+STATIC CONST UINT16 gCrc16LookupTable[256] =
+{
+ 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+ 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+ 0x0919, 0x1890, 0x2a0b, 0x3b82, 0x4f3d, 0x5eb4, 0x6c2f, 0x7da6,
+ 0x8551, 0x94d8, 0xa643, 0xb7ca, 0xc375, 0xd2fc, 0xe067, 0xf1ee,
+ 0x1232, 0x03bb, 0x3120, 0x20a9, 0x5416, 0x459f, 0x7704, 0x668d,
+ 0x9e7a, 0x8ff3, 0xbd68, 0xace1, 0xd85e, 0xc9d7, 0xfb4c, 0xeac5,
+ 0x1b2b, 0x0aa2, 0x3839, 0x29b0, 0x5d0f, 0x4c86, 0x7e1d, 0x6f94,
+ 0x9763, 0x86ea, 0xb471, 0xa5f8, 0xd147, 0xc0ce, 0xf255, 0xe3dc,
+ 0x2464, 0x35ed, 0x0776, 0x16ff, 0x6240, 0x73c9, 0x4152, 0x50db,
+ 0xa82c, 0xb9a5, 0x8b3e, 0x9ab7, 0xee08, 0xff81, 0xcd1a, 0xdc93,
+ 0x2d7d, 0x3cf4, 0x0e6f, 0x1fe6, 0x6b59, 0x7ad0, 0x484b, 0x59c2,
+ 0xa135, 0xb0bc, 0x8227, 0x93ae, 0xe711, 0xf698, 0xc403, 0xd58a,
+ 0x3656, 0x27df, 0x1544, 0x04cd, 0x7072, 0x61fb, 0x5360, 0x42e9,
+ 0xba1e, 0xab97, 0x990c, 0x8885, 0xfc3a, 0xedb3, 0xdf28, 0xcea1,
+ 0x3f4f, 0x2ec6, 0x1c5d, 0x0dd4, 0x796b, 0x68e2, 0x5a79, 0x4bf0,
+ 0xb307, 0xa28e, 0x9015, 0x819c, 0xf523, 0xe4aa, 0xd631, 0xc7b8,
+ 0x48c8, 0x5941, 0x6bda, 0x7a53, 0x0eec, 0x1f65, 0x2dfe, 0x3c77,
+ 0xc480, 0xd509, 0xe792, 0xf61b, 0x82a4, 0x932d, 0xa1b6, 0xb03f,
+ 0x41d1, 0x5058, 0x62c3, 0x734a, 0x07f5, 0x167c, 0x24e7, 0x356e,
+ 0xcd99, 0xdc10, 0xee8b, 0xff02, 0x8bbd, 0x9a34, 0xa8af, 0xb926,
+ 0x5afa, 0x4b73, 0x79e8, 0x6861, 0x1cde, 0x0d57, 0x3fcc, 0x2e45,
+ 0xd6b2, 0xc73b, 0xf5a0, 0xe429, 0x9096, 0x811f, 0xb384, 0xa20d,
+ 0x53e3, 0x426a, 0x70f1, 0x6178, 0x15c7, 0x044e, 0x36d5, 0x275c,
+ 0xdfab, 0xce22, 0xfcb9, 0xed30, 0x998f, 0x8806, 0xba9d, 0xab14,
+ 0x6cac, 0x7d25, 0x4fbe, 0x5e37, 0x2a88, 0x3b01, 0x099a, 0x1813,
+ 0xe0e4, 0xf16d, 0xc3f6, 0xd27f, 0xa6c0, 0xb749, 0x85d2, 0x945b,
+ 0x65b5, 0x743c, 0x46a7, 0x572e, 0x2391, 0x3218, 0x0083, 0x110a,
+ 0xe9fd, 0xf874, 0xcaef, 0xdb66, 0xafd9, 0xbe50, 0x8ccb, 0x9d42,
+ 0x7e9e, 0x6f17, 0x5d8c, 0x4c05, 0x38ba, 0x2933, 0x1ba8, 0x0a21,
+ 0xf2d6, 0xe35f, 0xd1c4, 0xc04d, 0xb4f2, 0xa57b, 0x97e0, 0x8669,
+ 0x7787, 0x660e, 0x5495, 0x451c, 0x31a3, 0x202a, 0x12b1, 0x0338,
+ 0xfbcf, 0xea46, 0xd8dd, 0xc954, 0xbdeb, 0xac62, 0x9ef9, 0x8f70
+};
+
+/**
+ Calculates the CRC16 checksum of the given buffer.
+
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The CRC16 checksum.
+**/
+UINT16
+CalculateCrc16 (
+ IN CONST VOID *Buffer,
+ IN UINTN Length,
+ IN UINT16 InitialValue
+ )
+{
+ CONST UINT8 *Buf;
+ UINT16 Crc;
+
+ Buf = Buffer;
+
+ Crc = ~InitialValue;
+
+ while(Length-- != 0) {
+ Crc = gCrc16LookupTable[(Crc & 0xFF) ^ *(Buf++)] ^ (Crc >> 8);
+ }
+
+ return ~Crc;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Crc32c.c b/Features/Ext4Pkg/Ext4Dxe/Crc32c.c
new file mode 100644
index 0000000000..d7ded93ab2
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Crc32c.c
@@ -0,0 +1,83 @@
+/** @file CRC32c calculation routines.
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Uefi.h>
+
+STATIC CONST UINT32 gCrc32cLookupTable[256] = {
+ 0x00000000, 0xf26b8303, 0xe13b70f7, 0x1350f3f4, 0xc79a971f, 0x35f1141c,
+ 0x26a1e7e8, 0xd4ca64eb, 0x8ad958cf, 0x78b2dbcc, 0x6be22838, 0x9989ab3b,
+ 0x4d43cfd0, 0xbf284cd3, 0xac78bf27, 0x5e133c24, 0x105ec76f, 0xe235446c,
+ 0xf165b798, 0x030e349b, 0xd7c45070, 0x25afd373, 0x36ff2087, 0xc494a384,
+ 0x9a879fa0, 0x68ec1ca3, 0x7bbcef57, 0x89d76c54, 0x5d1d08bf, 0xaf768bbc,
+ 0xbc267848, 0x4e4dfb4b, 0x20bd8ede, 0xd2d60ddd, 0xc186fe29, 0x33ed7d2a,
+ 0xe72719c1, 0x154c9ac2, 0x061c6936, 0xf477ea35, 0xaa64d611, 0x580f5512,
+ 0x4b5fa6e6, 0xb93425e5, 0x6dfe410e, 0x9f95c20d, 0x8cc531f9, 0x7eaeb2fa,
+ 0x30e349b1, 0xc288cab2, 0xd1d83946, 0x23b3ba45, 0xf779deae, 0x05125dad,
+ 0x1642ae59, 0xe4292d5a, 0xba3a117e, 0x4851927d, 0x5b016189, 0xa96ae28a,
+ 0x7da08661, 0x8fcb0562, 0x9c9bf696, 0x6ef07595, 0x417b1dbc, 0xb3109ebf,
+ 0xa0406d4b, 0x522bee48, 0x86e18aa3, 0x748a09a0, 0x67dafa54, 0x95b17957,
+ 0xcba24573, 0x39c9c670, 0x2a993584, 0xd8f2b687, 0x0c38d26c, 0xfe53516f,
+ 0xed03a29b, 0x1f682198, 0x5125dad3, 0xa34e59d0, 0xb01eaa24, 0x42752927,
+ 0x96bf4dcc, 0x64d4cecf, 0x77843d3b, 0x85efbe38, 0xdbfc821c, 0x2997011f,
+ 0x3ac7f2eb, 0xc8ac71e8, 0x1c661503, 0xee0d9600, 0xfd5d65f4, 0x0f36e6f7,
+ 0x61c69362, 0x93ad1061, 0x80fde395, 0x72966096, 0xa65c047d, 0x5437877e,
+ 0x4767748a, 0xb50cf789, 0xeb1fcbad, 0x197448ae, 0x0a24bb5a, 0xf84f3859,
+ 0x2c855cb2, 0xdeeedfb1, 0xcdbe2c45, 0x3fd5af46, 0x7198540d, 0x83f3d70e,
+ 0x90a324fa, 0x62c8a7f9, 0xb602c312, 0x44694011, 0x5739b3e5, 0xa55230e6,
+ 0xfb410cc2, 0x092a8fc1, 0x1a7a7c35, 0xe811ff36, 0x3cdb9bdd, 0xceb018de,
+ 0xdde0eb2a, 0x2f8b6829, 0x82f63b78, 0x709db87b, 0x63cd4b8f, 0x91a6c88c,
+ 0x456cac67, 0xb7072f64, 0xa457dc90, 0x563c5f93, 0x082f63b7, 0xfa44e0b4,
+ 0xe9141340, 0x1b7f9043, 0xcfb5f4a8, 0x3dde77ab, 0x2e8e845f, 0xdce5075c,
+ 0x92a8fc17, 0x60c37f14, 0x73938ce0, 0x81f80fe3, 0x55326b08, 0xa759e80b,
+ 0xb4091bff, 0x466298fc, 0x1871a4d8, 0xea1a27db, 0xf94ad42f, 0x0b21572c,
+ 0xdfeb33c7, 0x2d80b0c4, 0x3ed04330, 0xccbbc033, 0xa24bb5a6, 0x502036a5,
+ 0x4370c551, 0xb11b4652, 0x65d122b9, 0x97baa1ba, 0x84ea524e, 0x7681d14d,
+ 0x2892ed69, 0xdaf96e6a, 0xc9a99d9e, 0x3bc21e9d, 0xef087a76, 0x1d63f975,
+ 0x0e330a81, 0xfc588982, 0xb21572c9, 0x407ef1ca, 0x532e023e, 0xa145813d,
+ 0x758fe5d6, 0x87e466d5, 0x94b49521, 0x66df1622, 0x38cc2a06, 0xcaa7a905,
+ 0xd9f75af1, 0x2b9cd9f2, 0xff56bd19, 0x0d3d3e1a, 0x1e6dcdee, 0xec064eed,
+ 0xc38d26c4, 0x31e6a5c7, 0x22b65633, 0xd0ddd530, 0x0417b1db, 0xf67c32d8,
+ 0xe52cc12c, 0x1747422f, 0x49547e0b, 0xbb3ffd08, 0xa86f0efc, 0x5a048dff,
+ 0x8ecee914, 0x7ca56a17, 0x6ff599e3, 0x9d9e1ae0, 0xd3d3e1ab, 0x21b862a8,
+ 0x32e8915c, 0xc083125f, 0x144976b4, 0xe622f5b7, 0xf5720643, 0x07198540,
+ 0x590ab964, 0xab613a67, 0xb831c993, 0x4a5a4a90, 0x9e902e7b, 0x6cfbad78,
+ 0x7fab5e8c, 0x8dc0dd8f, 0xe330a81a, 0x115b2b19, 0x020bd8ed, 0xf0605bee,
+ 0x24aa3f05, 0xd6c1bc06, 0xc5914ff2, 0x37faccf1, 0x69e9f0d5, 0x9b8273d6,
+ 0x88d28022, 0x7ab90321, 0xae7367ca, 0x5c18e4c9, 0x4f48173d, 0xbd23943e,
+ 0xf36e6f75, 0x0105ec76, 0x12551f82, 0xe03e9c81, 0x34f4f86a, 0xc69f7b69,
+ 0xd5cf889d, 0x27a40b9e, 0x79b737ba, 0x8bdcb4b9, 0x988c474d, 0x6ae7c44e,
+ 0xbe2da0a5, 0x4c4623a6, 0x5f16d052, 0xad7d5351
+};
+
+/**
+ Calculates the CRC32c checksum of the given buffer.
+
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The CRC32c checksum.
+**/
+UINT32
+CalculateCrc32c (
+ IN CONST VOID *Buffer,
+ IN UINTN Length,
+ IN UINT32 InitialValue
+ )
+{
+ CONST UINT8 *Buf;
+ UINT32 Crc;
+
+ Buf = Buffer;
+ Crc = ~InitialValue;
+
+ while(Length-- != 0) {
+ Crc = gCrc32cLookupTable[(Crc & 0xFF) ^ *(Buf++)] ^ (Crc >> 8);
+ }
+
+ return ~Crc;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Directory.c b/Features/Ext4Pkg/Ext4Dxe/Directory.c
new file mode 100644
index 0000000000..7bda1b4b85
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Directory.c
@@ -0,0 +1,513 @@
+/** @file Directory related routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+#include <Library/BaseUcs2Utf8Lib.h>
+
+/**
+ Retrieves the filename of the directory entry and converts it to UTF-16/UCS-2
+
+ @param[in] Entry Pointer to a EXT4_DIR_ENTRY.
+ @param[out] Ucs2FileName Pointer to an array of CHAR16's, of size EXT4_NAME_MAX + 1.
+
+ @retval EFI_SUCCESS The filename was succesfully retrieved and converted to UCS2.
+ @retval !EFI_SUCCESS Failure.
+**/
+EFI_STATUS
+Ext4GetUcs2DirentName (
+ IN EXT4_DIR_ENTRY *Entry,
+ OUT CHAR16 Ucs2FileName[EXT4_NAME_MAX + 1]
+ )
+{
+ CHAR8 Utf8NameBuf[EXT4_NAME_MAX + 1];
+ UINT16 *Str;
+ EFI_STATUS Status;
+
+ CopyMem (Utf8NameBuf, Entry->name, Entry->name_len);
+
+ Utf8NameBuf[Entry->name_len] = '\0';
+
+ // Unfortunately, BaseUcs2Utf8Lib doesn't have a convert-buffer-to-buffer-like
+ // function. Therefore, we need to allocate from the pool (inside UTF8StrToUCS2),
+ // copy it to our out buffer (Ucs2FileName) and free.
+
+ Status = UTF8StrToUCS2 (Utf8NameBuf, &Str);
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = StrCpyS (Ucs2FileName, EXT4_NAME_MAX + 1, Str);
+
+ FreePool (Str);
+
+ return Status;
+}
+
+/**
+ Retrieves a directory entry.
+
+ @param[in] Directory Pointer to the opened directory.
+ @param[in] NameUnicode Pointer to the UCS-2 formatted filename.
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[out] Result Pointer to the destination directory entry.
+
+ @return The result of the operation.
+**/
+EFI_STATUS
+Ext4RetrieveDirent (
+ IN EXT4_FILE *Directory,
+ IN CONST CHAR16 *Name,
+ IN EXT4_PARTITION *Partition,
+ OUT EXT4_DIR_ENTRY *Result
+ )
+{
+ EFI_STATUS Status;
+ CHAR8 *Buf;
+ UINT64 Off;
+ EXT4_INODE *Inode;
+ UINT64 DirInoSize;
+ UINT32 BlockRemainder;
+
+ Status = EFI_NOT_FOUND;
+ Buf = AllocatePool (Partition->BlockSize);
+
+ if(Buf == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ Off = 0;
+
+ Inode = Directory->Inode;
+ DirInoSize = EXT4_INODE_SIZE (Inode);
+
+ DivU64x32Remainder (DirInoSize, Partition->BlockSize, &BlockRemainder);
+ if(BlockRemainder != 0) {
+ // Directory inodes need to have block aligned sizes
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ while(Off < DirInoSize) {
+ UINTN Length;
+ CHAR8 *BufPtr;
+
+ Length = Partition->BlockSize;
+
+ Status = Ext4Read (Partition, Directory, Buf, Off, &Length);
+
+ if (Status != EFI_SUCCESS) {
+ FreePool (Buf);
+ return Status;
+ }
+
+ for(BufPtr = Buf; BufPtr < Buf + Partition->BlockSize; ) {
+ EXT4_DIR_ENTRY *Entry;
+ UINTN RemainingBlock;
+
+ Entry = (EXT4_DIR_ENTRY *)BufPtr;
+ if (Entry->rec_len == 0) {
+ FreePool (Buf);
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ RemainingBlock = Partition->BlockSize - (BufPtr - Buf);
+
+ if(Entry->name_len > RemainingBlock || Entry->rec_len > RemainingBlock) {
+ // Corrupted filesystem
+ // TODO: Might be a good idea to do the normal ext4 corruption detection thing
+ // and dirty the filesystem.
+ FreePool (Buf);
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ // Ignore names bigger than our limit.
+
+ /* Note: I think having a limit is sane because:
+ 1) It's nicer to work with.
+ 2) Linux and a number of BSDs also have a filename limit of 255.
+ */
+ if(Entry->name_len > EXT4_NAME_MAX) {
+ continue;
+ }
+
+ // Unused entry
+ if(Entry->inode == 0) {
+ BufPtr += Entry->rec_len;
+ continue;
+ }
+
+ CHAR16 Ucs2FileName[EXT4_NAME_MAX + 1];
+
+ Status = Ext4GetUcs2DirentName (Entry, Ucs2FileName);
+
+ /* In theory, this should never fail.
+ * In reality, it's quite possible that it can fail, considering filenames in
+ * Linux (and probably other nixes) are just null-terminated bags of bytes, and don't
+ * need to form valid ASCII/UTF-8 sequences.
+ */
+ if (EFI_ERROR (Status)) {
+ // If we error out, skip this entry
+ // I'm not sure if this is correct behaviour, but I don't think there's a precedent here.
+ BufPtr += Entry->rec_len;
+ continue;
+ }
+
+ if (Entry->name_len == StrLen (Name) &&
+ !Ext4StrCmpInsensitive (Ucs2FileName, (CHAR16 *)Name)) {
+ UINTN ToCopy;
+
+ ToCopy = MIN (Entry->rec_len, sizeof (EXT4_DIR_ENTRY));
+
+ CopyMem (Result, Entry, ToCopy);
+ FreePool (Buf);
+ return EFI_SUCCESS;
+ }
+
+ BufPtr += Entry->rec_len;
+ }
+
+ Off += Partition->BlockSize;
+ }
+
+ FreePool (Buf);
+ return EFI_NOT_FOUND;
+}
+
+/**
+ Opens a file using a directory entry.
+
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] OpenMode Mode in which the file is supposed to be open.
+ @param[out] OutFile Pointer to the newly opened file.
+ @param[in] Entry Directory entry to be used.
+
+ @retval EFI_STATUS Result of the operation
+**/
+EFI_STATUS
+Ext4OpenDirent (
+ IN EXT4_PARTITION *Partition,
+ IN UINT64 OpenMode,
+ OUT EXT4_FILE **OutFile,
+ IN EXT4_DIR_ENTRY *Entry
+ )
+{
+ EFI_STATUS Status;
+ CHAR16 FileName[EXT4_NAME_MAX + 1];
+ EXT4_FILE *File;
+
+ File = AllocateZeroPool (sizeof (EXT4_FILE));
+
+ if (File == NULL) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto Error;
+ }
+
+ Status = Ext4GetUcs2DirentName (Entry, FileName);
+
+ if (EFI_ERROR (Status)) {
+ goto Error;
+ }
+
+ File->FileName = AllocateZeroPool (StrSize (FileName));
+
+ if (!File->FileName) {
+ Status = EFI_OUT_OF_RESOURCES;
+ goto Error;
+ }
+
+ Status = Ext4InitExtentsMap (File);
+
+ if (EFI_ERROR (Status)) {
+ goto Error;
+ }
+
+ // This should not fail.
+ StrCpyS (File->FileName, ARRAY_SIZE (FileName), FileName);
+
+ File->InodeNum = Entry->inode;
+
+ Ext4SetupFile (File, Partition);
+
+ Status = Ext4ReadInode (Partition, Entry->inode, &File->Inode);
+
+ if (EFI_ERROR (Status)) {
+ goto Error;
+ }
+
+ *OutFile = File;
+
+ InsertTailList (&Partition->OpenFiles, &File->OpenFilesListNode);
+
+ return EFI_SUCCESS;
+
+Error:
+ if (File != NULL) {
+ if (File->FileName != NULL) {
+ FreePool (File->FileName);
+ }
+
+ if (File->ExtentsMap != NULL) {
+ OrderedCollectionUninit (File->ExtentsMap);
+ }
+
+ FreePool (File);
+ }
+
+ return Status;
+}
+
+/**
+ Opens a file.
+
+ @param[in] Directory Pointer to the opened directory.
+ @param[in] Name Pointer to the UCS-2 formatted filename.
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] OpenMode Mode in which the file is supposed to be open.
+ @param[out] OutFile Pointer to the newly opened file.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4OpenFile (
+ IN EXT4_FILE *Directory,
+ IN CONST CHAR16 *Name,
+ IN EXT4_PARTITION *Partition,
+ IN UINT64 OpenMode,
+ OUT EXT4_FILE **OutFile
+ )
+{
+ EXT4_DIR_ENTRY Entry;
+ EFI_STATUS Status;
+
+ Status = Ext4RetrieveDirent (Directory, Name, Partition, &Entry);
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ // EFI requires us to error out on ".." opens for the root directory
+ if (Entry.inode == Directory->InodeNum) {
+ return EFI_NOT_FOUND;
+ }
+
+ return Ext4OpenDirent (Partition, OpenMode, OutFile, &Entry);
+}
+
+/**
+ Open the root directory on a volume.
+
+ @param This A pointer to the volume to open the root directory.
+ @param Root A pointer to the location to return the opened file handle for the
+ root directory.
+
+ @retval EFI_SUCCESS The device was opened.
+ @retval EFI_UNSUPPORTED This volume does not support the requested file system type.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_ACCESS_DENIED The service denied access to the file.
+ @retval EFI_OUT_OF_RESOURCES The volume was not opened due to lack of resources.
+ @retval EFI_MEDIA_CHANGED The device has a different medium in it or the medium is no
+ longer supported. Any existing file handles for this volume are
+ no longer valid. To access the files on the new medium, the
+ volume must be reopened with OpenVolume().
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4OpenVolume (
+ EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *This, EFI_FILE_PROTOCOL **Root
+ )
+{
+ EXT4_INODE *RootInode;
+ EFI_STATUS Status;
+
+ // 2 is always the root inode number in ext4
+ Status = Ext4ReadInode ((EXT4_PARTITION *)This, 2, &RootInode);
+
+ if(EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Could not open root inode - status %x\n", Status));
+ return Status;
+ }
+
+ EXT4_FILE *RootDir = AllocateZeroPool (sizeof (EXT4_FILE));
+
+ if(!RootDir) {
+ FreePool (RootInode);
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ // The filename will be "\"(null terminated of course)
+ RootDir->FileName = AllocateZeroPool (2 * sizeof (CHAR16));
+
+ if (!RootDir->FileName) {
+ FreePool (RootDir);
+ FreePool (RootInode);
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ RootDir->FileName[0] = L'\\';
+
+ RootDir->Inode = RootInode;
+ RootDir->InodeNum = 2;
+
+ Status = Ext4InitExtentsMap (RootDir);
+
+ if (EFI_ERROR (Status)) {
+ FreePool (RootDir->FileName);
+ FreePool (RootInode);
+ FreePool (RootDir);
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ Ext4SetupFile (RootDir, (EXT4_PARTITION *)This);
+ *Root = &RootDir->Protocol;
+
+ InsertTailList (&((EXT4_PARTITION *)This)->OpenFiles, &RootDir->OpenFilesListNode);
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Validates a directory entry.
+
+ @param[in] Dirent Pointer to the directory entry.
+
+ @retval TRUE Valid directory entry.
+ FALSE Invalid directory entry.
+**/
+STATIC
+BOOLEAN
+Ext4ValidDirent (
+ IN CONST EXT4_DIR_ENTRY *Dirent
+ )
+{
+ UINTN RequiredSize;
+
+ RequiredSize = Dirent->name_len + EXT4_MIN_DIR_ENTRY_LEN;
+
+ if (Dirent->rec_len < RequiredSize) {
+ DEBUG ((DEBUG_ERROR, "[ext4] dirent size %lu too small (compared to %lu)\n", Dirent->rec_len, RequiredSize));
+ return FALSE;
+ }
+
+ // Dirent sizes need to be 4 byte aligned
+ if (Dirent->rec_len % 4) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Reads a directory entry.
+
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] File Pointer to the open directory.
+ @param[out] Buffer Pointer to the output buffer.
+ @param[in] Offset Initial directory position.
+ @param[in out] OutLength Pointer to a UINTN that contains the length of the buffer,
+ and the length of the actual EFI_FILE_INFO after the call.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4ReadDir (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ OUT VOID *Buffer,
+ IN UINT64 Offset,
+ IN OUT UINTN *OutLength
+ )
+{
+ DEBUG ((DEBUG_INFO, "[ext4] Ext4ReadDir offset %lu\n", Offset));
+ EXT4_INODE *DirIno;
+ EFI_STATUS Status;
+ UINT64 DirInoSize;
+ UINTN Len;
+ UINT32 BlockRemainder;
+ EXT4_DIR_ENTRY Entry;
+
+ DirIno = File->Inode;
+ Status = EFI_SUCCESS;
+ DirInoSize = Ext4InodeSize (DirIno);
+
+ DivU64x32Remainder (DirInoSize, Partition->BlockSize, &BlockRemainder);
+ if(BlockRemainder != 0) {
+ // Directory inodes need to have block aligned sizes
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ while(TRUE) {
+ EXT4_FILE *TempFile;
+
+ TempFile = NULL;
+
+ // We (try to) read the maximum size of a directory entry at a time
+ // Note that we don't need to read any padding that may exist after it.
+ Len = sizeof (Entry);
+ Status = Ext4Read (Partition, File, &Entry, Offset, &Len);
+
+ if (EFI_ERROR (Status)) {
+ goto Out;
+ }
+
+ #if 0
+ DEBUG ((DEBUG_INFO, "[ext4] Length read %lu, offset %lu\n", Len, Offset));
+ #endif
+
+ if (Len == 0) {
+ *OutLength = 0;
+ Status = EFI_SUCCESS;
+ goto Out;
+ }
+
+ if (Len < EXT4_MIN_DIR_ENTRY_LEN) {
+ Status = EFI_VOLUME_CORRUPTED;
+ goto Out;
+ }
+
+ // Invalid directory entry length
+ if (!Ext4ValidDirent (&Entry)) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Invalid dirent at offset %lu\n", Offset));
+ Status = EFI_VOLUME_CORRUPTED;
+ goto Out;
+ }
+
+ DEBUG ((DEBUG_INFO, "[ext4] dirent size %lu\n", Entry.rec_len));
+
+ if (Entry.inode == 0) {
+ // When inode = 0, it's unused
+ Offset += Entry.rec_len;
+ continue;
+ }
+
+ Status = Ext4OpenDirent (Partition, EFI_FILE_MODE_READ, &TempFile, &Entry);
+
+ if (EFI_ERROR (Status)) {
+ goto Out;
+ }
+
+ #if 0
+ DEBUG ((DEBUG_INFO, "[ext4] Listing file %s\n", TempFile->FileName));
+ #endif
+
+ Status = Ext4GetFileInfo (TempFile, Buffer, OutLength);
+ if (!EFI_ERROR (Status)) {
+ File->Position = Offset + Entry.rec_len;
+ }
+
+ Ext4CloseInternal (TempFile);
+
+ goto Out;
+ }
+
+ Status = EFI_SUCCESS;
+Out:
+ return Status;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c b/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
new file mode 100644
index 0000000000..57622a9f25
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
@@ -0,0 +1,106 @@
+/** @file Disk utilities
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+#include "Ext4Dxe.h"
+
+/**
+ Reads from the partition's disk using the DISK_IO protocol.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[out] Buffer Pointer to a destination buffer.
+ @param[in] Length Length of the destination buffer.
+ @param[in] Offset Offset, in bytes, of the location to read.
+
+ @return Success status of the disk read.
+**/
+EFI_STATUS
+Ext4ReadDiskIo (
+ IN EXT4_PARTITION *Partition,
+ OUT VOID *Buffer,
+ IN UINTN Length,
+ IN UINT64 Offset
+ )
+{
+ return Ext4DiskIo (Partition)->ReadDisk (Ext4DiskIo (Partition), Ext4MediaId (Partition), Offset, Length, Buffer);
+}
+
+/**
+ Reads blocks from the partition's disk using the DISK_IO protocol.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[out] Buffer Pointer to a destination buffer.
+ @param[in] NumberBlocks Length of the read, in filesystem blocks.
+ @param[in] BlockNumber Starting block number.
+
+ @return Success status of the read.
+**/
+EFI_STATUS
+Ext4ReadBlocks (
+ IN EXT4_PARTITION *Partition,
+ OUT VOID *Buffer,
+ IN UINTN NumberBlocks,
+ IN EXT4_BLOCK_NR BlockNumber
+ )
+{
+ UINT64 Offset;
+ UINTN Length;
+
+ Offset = MultU64x32 (BlockNumber, Partition->BlockSize);
+ Length = NumberBlocks * Partition->BlockSize;
+
+ // Check for overflow on the block -> byte conversions.
+ // Partition->BlockSize is never 0, so we don't need to check for that.
+
+ if (Offset > DivU64x32 ((UINT64)- 1, Partition->BlockSize)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (Length > (UINTN)- 1/Partition->BlockSize) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ return Ext4ReadDiskIo (Partition, Buffer, Length, Offset);
+}
+
+/**
+ Allocates a buffer and reads blocks from the partition's disk using the DISK_IO protocol.
+ This function is deprecated and will be removed in the future.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[in] NumberBlocks Length of the read, in filesystem blocks.
+ @param[in] BlockNumber Starting block number.
+
+ @return Buffer allocated by AllocatePool, or NULL if some part of the process
+ failed.
+**/
+VOID *
+Ext4AllocAndReadBlocks (
+ IN EXT4_PARTITION *Partition,
+ IN UINTN NumberBlocks,
+ IN EXT4_BLOCK_NR BlockNumber
+ )
+{
+ VOID *Buf;
+ UINTN Length;
+
+ Length = NumberBlocks * Partition->BlockSize;
+
+ if (Length > (UINTN)- 1/Partition->BlockSize) {
+ return NULL;
+ }
+
+ Buf = AllocatePool (Length);
+
+ if(Buf == NULL) {
+ return NULL;
+ }
+
+ if(Ext4ReadBlocks (Partition, Buf, NumberBlocks, BlockNumber) != EFI_SUCCESS) {
+ FreePool (Buf);
+ return NULL;
+ }
+
+ return Buf;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h b/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h
new file mode 100644
index 0000000000..de8f12c426
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h
@@ -0,0 +1,455 @@
+/** @file Raw filesystem data structures
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+ Layout of an EXT2/3/4 filesystem:
+ (note: this driver has been developed using
+ https://www.kernel.org/doc/html/latest/filesystems/ext4/index.html as
+ documentation).
+
+ An ext2/3/4 filesystem (here on out referred to as simply an ext4 filesystem,
+ due to the similarities) is composed of various concepts:
+
+ 1) Superblock
+ The superblock is the structure near (1024 bytes offset from the start)
+ the start of the partition, and describes the filesystem in general.
+ Here, we get to know the size of the filesystem's blocks, which features
+ it supports or not, whether it's been cleanly unmounted, how many blocks
+ we have, etc.
+
+ 2) Block groups
+ EXT4 filesystems are divided into block groups, and each block group covers
+ s_blocks_per_group(8 * Block Size) blocks. Each block group has an
+ associated block group descriptor; these are present directly after the
+ superblock. Each block group descriptor contains the location of the
+ inode table, and the inode and block bitmaps (note these bitmaps are only
+ a block long, which gets us the 8 * Block Size formula covered previously).
+
+ 3) Blocks
+ The ext4 filesystem is divided in blocks, of size s_log_block_size ^ 1024.
+ Blocks can be allocated using individual block groups's bitmaps. Note
+ that block 0 is invalid and its presence on extents/block tables means
+ it's part of a file hole, and that particular location must be read as
+ a block full of zeros.
+
+ 4) Inodes
+ The ext4 filesystem divides files/directories into inodes (originally
+ index nodes). Each file/socket/symlink/directory/etc (here on out referred
+ to as a file, since there is no distinction under the ext4 filesystem) is
+ stored as a /nameless/ inode, that is stored in some block group's inode
+ table. Each inode has s_inode_size size (or GOOD_OLD_INODE_SIZE if it's
+ an old filesystem), and holds various metadata about the file. Since the
+ largest inode structure right now is ~160 bytes, the rest of the inode
+ contains inline extended attributes. Inodes' data is stored using either
+ data blocks (under ext2/3) or extents (under ext4).
+
+ 5) Extents
+ Ext4 inodes store data in extents. These let N contiguous logical blocks
+ that are represented by N contiguous physical blocks be represented by a
+ single extent structure, which minimizes filesystem metadata bloat and
+ speeds up block mapping (particularly due to the fact that high-quality
+ ext4 implementations like linux's try /really/ hard to make the file
+ contiguous, so it's common to have files with almost 0 fragmentation).
+ Inodes that use extents store them in a tree, and the top of the tree
+ is stored on i_data. The tree's leaves always start with an
+ EXT4_EXTENT_HEADER and contain EXT4_EXTENT_INDEX on eh_depth != 0 and
+ EXT4_EXTENT on eh_depth = 0; these entries are always sorted by logical
+ block.
+
+ 6) Directories
+ Ext4 directories are files that store name -> inode mappings for the
+ logical directory; this is where files get their names, which means ext4
+ inodes do not themselves have names, since they can be linked (present)
+ multiple times with different names. Directories can store entries in two
+ different ways:
+ 1) Classical linear directories: They store entries as a mostly-linked
+ mostly-list of EXT4_DIR_ENTRY.
+ 2) Hash tree directories: These are used for larger directories, with
+ hundreds of entries, and are designed in a backwards compatible way.
+ These are not yet implemented in the Ext4Dxe driver.
+
+ 7) Journal
+ Ext3/4 filesystems have a journal to help protect the filesystem against
+ system crashes. This is not yet implemented in Ext4Dxe but is described
+ in detail in the Linux kernel's documentation.
+**/
+
+#ifndef EXT4_DISK_H_
+#define EXT4_DISK_H_
+
+#include <Uefi.h>
+
+#define EXT4_SUPERBLOCK_OFFSET 1024U
+
+#define EXT4_SIGNATURE 0xEF53U
+
+#define EXT4_FS_STATE_UNMOUNTED 0x1
+#define EXT4_FS_STATE_ERRORS_DETECTED 0x2
+#define EXT4_FS_STATE_RECOVERING_ORPHANS 0x4
+
+#define EXT4_ERRORS_CONTINUE 1
+#define EXT4_ERRORS_RO 2
+#define EXT4_ERRORS_PANIC 3
+
+#define EXT4_LINUX_ID 0
+#define EXT4_GNU_HURD_ID 1
+#define EXT4_MASIX_ID 2
+#define EXT4_FREEBSD_ID 3
+#define EXT4_LITES_ID 4
+
+#define EXT4_GOOD_OLD_REV 0
+#define EXT4_DYNAMIC_REV 1
+
+#define EXT4_CHECKSUM_CRC32C 0x1
+
+#define EXT4_FEATURE_COMPAT_DIR_PREALLOC 0x01
+#define EXT4_FEATURE_COMPAT_IMAGIC_INODES 0x02
+#define EXT3_FEATURE_COMPAT_HAS_JOURNAL 0x04
+#define EXT4_FEATURE_COMPAT_EXT_ATTR 0x08
+#define EXT4_FEATURE_COMPAT_RESIZE_INO 0x10
+#define EXT4_FEATURE_COMPAT_DIR_INDEX 0x20
+
+#define EXT4_FEATURE_INCOMPAT_COMPRESSION 0x00001
+#define EXT4_FEATURE_INCOMPAT_FILETYPE 0x00002
+#define EXT4_FEATURE_INCOMPAT_RECOVER 0x00004
+#define EXT4_FEATURE_INCOMPAT_JOURNAL_DEV 0x00008
+#define EXT4_FEATURE_INCOMPAT_META_BG 0x00010
+#define EXT4_FEATURE_INCOMPAT_EXTENTS 0x00040
+#define EXT4_FEATURE_INCOMPAT_64BIT 0x00080
+#define EXT4_FEATURE_INCOMPAT_MMP 0x00100
+#define EXT4_FEATURE_INCOMPAT_FLEX_BG 0x00200
+#define EXT4_FEATURE_INCOMPAT_EA_INODE 0x00400
+// It's not clear whether or not this feature (below) is used right now
+#define EXT4_FEATURE_INCOMPAT_DIRDATA 0x01000
+#define EXT4_FEATURE_INCOMPAT_CSUM_SEED 0x02000
+#define EXT4_FEATURE_INCOMPAT_LARGEDIR 0x04000
+#define EXT4_FEATURE_INCOMPAT_INLINE_DATA 0x08000
+#define EXT4_FEATURE_INCOMPAT_ENCRYPT 0x10000
+
+#define EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER 0x0001
+#define EXT4_FEATURE_RO_COMPAT_LARGE_FILE 0x0002
+#define EXT4_FEATURE_RO_COMPAT_BTREE_DIR 0x0004 // Unused
+#define EXT4_FEATURE_RO_COMPAT_HUGE_FILE 0x0008
+#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM 0x0010
+#define EXT4_FEATURE_RO_COMPAT_DIR_NLINK 0x0020
+#define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE 0x0040
+#define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT 0x0080 // Not implemented in ext4
+#define EXT4_FEATURE_RO_COMPAT_QUOTA 0x0100
+#define EXT4_FEATURE_RO_COMPAT_BIGALLOC 0x0200
+#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM 0x0400
+#define EXT4_FEATURE_RO_COMPAT_REPLICA 0x0800 // Not used
+
+// We explicitly don't recognise this, so we get read only.
+#define EXT4_FEATURE_RO_COMPAT_READONLY 0x1000
+#define EXT4_FEATURE_RO_COMPAT_PROJECT 0x2000
+
+/* Important notes about the features
+ * Absolutely needed features:
+ * 1) Every incompat, because we might want to mount root filesystems
+ * 2) Relevant RO_COMPATs(I'm not sure of what to do wrt quota, project)
+**/
+
+#define EXT4_INO_TYPE_FIFO 0x1000
+#define EXT4_INO_TYPE_CHARDEV 0x2000
+#define EXT4_INO_TYPE_DIR 0x4000
+#define EXT4_INO_TYPE_BLOCKDEV 0x6000
+#define EXT4_INO_TYPE_REGFILE 0x8000
+#define EXT4_INO_TYPE_SYMLINK 0xA000
+#define EXT4_INO_TYPE_UNIX_SOCK 0xC000
+
+/* Inode flags */
+#define EXT4_SECRM_FL 0x00000001
+#define EXT4_UNRM_FL 0x00000002
+#define EXT4_COMPR_FL 0x00000004
+#define EXT4_SYNC_FL 0x00000008
+#define EXT4_IMMUTABLE_FL 0x00000010
+#define EXT4_APPEND_FL 0x00000020
+#define EXT4_NODUMP_FL 0x00000040
+#define EXT4_NOATIME_FL 0x00000080
+#define EXT4_DIRTY_FL 0x00000100
+#define EXT4_COMPRBLK_FL 0x00000200
+#define EXT4_NOCOMPR_FL 0x00000400
+#define EXT4_ECOMPR_FL 0x00000800
+#define EXT4_BTREE_FL 0x00001000
+#define EXT4_INDEX_FL 0x00002000
+#define EXT4_JOURNAL_DATA_FL 0x00004000
+#define EXT4_NOTAIL_FL 0x00008000
+#define EXT4_DIRSYNC_FL 0x00010000
+#define EXT4_TOPDIR_FL 0x00020000
+#define EXT4_HUGE_FILE_FL 0x00040000
+#define EXT4_EXTENTS_FL 0x00080000
+#define EXT4_VERITY_FL 0x00100000
+#define EXT4_EA_INODE_FL 0x00200000
+#define EXT4_RESERVED_FL 0x80000000
+
+/* File type flags that are stored in the directory entries */
+#define EXT4_FT_UNKNOWN 0
+#define EXT4_FT_REG_FILE 1
+#define EXT4_FT_DIR 2
+#define EXT4_FT_CHRDEV 3
+#define EXT4_FT_BLKDEV 4
+#define EXT4_FT_FIFO 5
+#define EXT4_FT_SOCK 6
+#define EXT4_FT_SYMLINK 7
+
+typedef struct {
+ UINT32 s_inodes_count;
+ UINT32 s_blocks_count;
+ UINT32 s_r_blocks_count;
+ UINT32 s_free_blocks_count;
+ UINT32 s_free_inodes_count;
+ UINT32 s_first_data_block;
+ UINT32 s_log_block_size;
+ UINT32 s_log_frag_size;
+ UINT32 s_blocks_per_group;
+ UINT32 s_frags_per_group;
+ UINT32 s_inodes_per_group;
+ UINT32 s_mtime;
+ UINT32 s_wtime;
+ UINT16 s_mnt_count;
+ UINT16 s_max_mnt_count;
+ UINT16 s_magic;
+ UINT16 s_state;
+ UINT16 s_errors;
+ UINT16 s_minor_rev_level;
+ UINT32 s_lastcheck;
+ UINT32 s_check_interval;
+ UINT32 s_creator_os;
+ UINT32 s_rev_level;
+ UINT16 s_def_resuid;
+ UINT16 s_def_resgid;
+
+ /* Every field after this comment is revision >= 1 */
+
+ UINT32 s_first_ino;
+ UINT16 s_inode_size;
+ UINT16 s_block_group_nr;
+ UINT32 s_feature_compat;
+ UINT32 s_feature_incompat;
+ UINT32 s_feature_ro_compat;
+ UINT8 s_uuid[16];
+ UINT8 s_volume_name[16];
+ UINT8 s_last_mounted[64];
+ UINT32 s_algo_bitmap;
+ UINT8 s_prealloc_blocks;
+ UINT8 s_prealloc_dir_blocks;
+ UINT16 unused;
+ UINT8 s_journal_uuid[16];
+ UINT32 s_journal_inum;
+ UINT32 s_journal_dev;
+ UINT32 s_last_orphan;
+ UINT32 s_hash_seed[4];
+ UINT8 s_def_hash_version;
+ UINT8 s_jnl_backup_type;
+ UINT16 s_desc_size;
+ UINT32 s_default_mount_options;
+ UINT32 s_first_meta_bg;
+ UINT32 s_mkfs_time;
+ UINT32 s_jnl_blocks[17];
+ UINT32 s_blocks_count_hi;
+ UINT32 s_r_blocks_count_hi;
+ UINT32 s_free_blocks_count_hi;
+ UINT16 s_min_extra_isize;
+ UINT16 s_want_extra_isize;
+ UINT32 s_flags;
+ UINT16 s_raid_stride;
+ UINT16 s_mmp_interval;
+ UINT64 s_mmp_block;
+ UINT32 s_raid_stride_width;
+ UINT8 s_log_groups_per_flex;
+ UINT8 s_checksum_type; // Only valid value is 1 - CRC32C
+ UINT16 s_reserved_pad;
+ UINT64 s_kbytes_written;
+
+ // Snapshot stuff isn't used in Linux and isn't implemented here
+ UINT32 s_snapshot_inum;
+ UINT32 s_snapshot_id;
+ UINT64 s_snapshot_r_blocks_count;
+ UINT32 s_snapshot_list;
+ UINT32 s_error_count;
+ UINT32 s_first_error_time;
+ UINT32 s_first_error_ino;
+ UINT64 s_first_error_block;
+ UINT8 s_first_error_func[32];
+ UINT32 s_first_error_line;
+ UINT32 s_last_error_time;
+ UINT32 s_last_error_ino;
+ UINT32 s_last_error_line;
+ UINT64 s_last_error_block;
+ UINT8 s_last_error_func[32];
+ UINT8 s_mount_opts[64];
+ UINT32 s_usr_quota_inum;
+ UINT32 s_grp_quota_inum;
+ UINT32 s_overhead_blocks;
+ UINT32 s_backup_bgs[2]; // sparse_super2
+ UINT8 s_encrypt_algos[4];
+ UINT8 s_encrypt_pw_salt[16];
+ UINT32 s_lpf_ino;
+ UINT32 s_prj_quota_inum;
+ UINT32 s_checksum_seed;
+ UINT32 s_reserved[98];
+ UINT32 s_checksum;
+} EXT4_SUPERBLOCK;
+
+STATIC_ASSERT (sizeof (EXT4_SUPERBLOCK) == 1024, "ext4 superblock struct has incorrect size");
+
+typedef struct {
+ UINT32 bg_block_bitmap_lo;
+ UINT32 bg_inode_bitmap_lo;
+ UINT32 bg_inode_table_lo;
+ UINT16 bg_free_blocks_count_lo;
+ UINT16 bg_free_inodes_count_lo;
+ UINT16 bg_used_dirs_count_lo;
+ UINT16 bg_flags;
+ UINT32 bg_exclude_bitmap_lo;
+ UINT16 bg_block_bitmap_csum_lo;
+ UINT16 bg_inode_bitmap_csum_lo;
+ UINT16 bg_itable_unused_lo;
+ UINT16 bg_checksum;
+ UINT32 bg_block_bitmap_hi;
+ UINT32 bg_inode_bitmap_hi;
+ UINT32 bg_inode_table_hi;
+ UINT16 bg_free_blocks_count_hi;
+ UINT16 bg_free_inodes_count_hi;
+ UINT16 bg_used_dirs_count_hi;
+ UINT16 bg_itable_unused_hi;
+ UINT32 bg_exclude_bitmap_hi;
+ UINT16 bg_block_bitmap_csum_hi;
+ UINT16 bg_inode_bitmap_csum_hi;
+ UINT32 bg_reserved;
+} EXT4_BLOCK_GROUP_DESC;
+
+#define EXT4_OLD_BLOCK_DESC_SIZE 32
+#define EXT4_64BIT_BLOCK_DESC_SIZE 64
+
+STATIC_ASSERT (
+ sizeof (EXT4_BLOCK_GROUP_DESC) == EXT4_64BIT_BLOCK_DESC_SIZE,
+ "ext4 block group descriptor struct has incorrect size"
+ );
+
+#define EXT4_DBLOCKS 12
+#define EXT4_IND_BLOCK 12
+#define EXT4_DIND_BLOCK 13
+#define EXT4_TIND_BLOCK 14
+#define EXT4_NR_BLOCKS 15
+
+#define EXT4_GOOD_OLD_INODE_SIZE 128
+
+typedef struct _Ext4_I_OSD2_Linux {
+ UINT16 l_i_blocks_high;
+ UINT16 l_i_file_acl_high;
+ UINT16 l_i_uid_high;
+ UINT16 l_i_gid_high;
+ UINT16 l_i_checksum_lo;
+ UINT16 l_i_reserved;
+} EXT4_OSD2_LINUX;
+
+typedef struct _Ext4_I_OSD2_Hurd {
+ UINT16 h_i_reserved1;
+ UINT16 h_i_mode_high;
+ UINT16 h_i_uid_high;
+ UINT16 h_i_gid_high;
+ UINT32 h_i_author;
+} EXT4_OSD2_HURD;
+
+typedef union {
+ // Note: Toolchain-specific defines (such as "linux") stops us from using simpler names down here.
+ EXT4_OSD2_LINUX data_linux;
+ EXT4_OSD2_HURD data_hurd;
+} EXT4_OSD2;
+
+typedef struct _Ext4Inode {
+ UINT16 i_mode;
+ UINT16 i_uid;
+ UINT32 i_size_lo;
+ UINT32 i_atime;
+ UINT32 i_ctime;
+ UINT32 i_mtime;
+ UINT32 i_dtime;
+ UINT16 i_gid;
+ UINT16 i_links;
+ UINT32 i_blocks;
+ UINT32 i_flags;
+ UINT32 i_os_spec;
+ UINT32 i_data[EXT4_NR_BLOCKS];
+ UINT32 i_generation;
+ UINT32 i_file_acl;
+ UINT32 i_size_hi;
+ UINT32 i_faddr;
+
+ EXT4_OSD2 i_osd2;
+
+ UINT16 i_extra_isize;
+ UINT16 i_checksum_hi;
+ UINT32 i_ctime_extra;
+ UINT32 i_mtime_extra;
+ UINT32 i_atime_extra;
+ UINT32 i_crtime;
+ UINT32 i_crtime_extra;
+ UINT32 i_version_hi;
+ UINT32 i_projid;
+} EXT4_INODE;
+
+typedef struct {
+ UINT32 inode;
+ UINT16 rec_len;
+ UINT8 name_len;
+ UINT8 file_type;
+ CHAR8 name[255];
+} EXT4_DIR_ENTRY;
+
+#define EXT4_MIN_DIR_ENTRY_LEN 8
+
+// This on-disk structure is present at the bottom of the extent tree
+typedef struct {
+ // First logical block
+ UINT32 ee_block;
+ // Length of the extent, in blocks
+ UINT16 ee_len;
+ // The physical (filesystem-relative) block is split between the high 16 bits
+ // and the low 32 bits - this forms a 48-bit block number
+ UINT16 ee_start_hi;
+ UINT32 ee_start_lo;
+} EXT4_EXTENT;
+
+// This on-disk structure is present at all levels except the bottom
+typedef struct {
+ // This index covers logical blocks from 'ei_block'
+ UINT32 ei_block;
+ // Block of the next level of the extent tree, similarly split in a high and low portion.
+ UINT32 ei_leaf_lo;
+ UINT16 ei_leaf_hi;
+
+ UINT16 ei_unused;
+} EXT4_EXTENT_INDEX;
+
+typedef struct {
+ // Needs to be EXT4_EXTENT_HEADER_MAGIC
+ UINT16 eh_magic;
+ // Number of entries
+ UINT16 eh_entries;
+ // Maximum number of entries that could follow this header
+ UINT16 eh_max;
+ // Depth of this node in the tree - the tree can be at most 5 levels deep
+ UINT16 eh_depth;
+ // Unused by standard ext4
+ UINT32 eh_generation;
+} EXT4_EXTENT_HEADER;
+
+#define EXT4_EXTENT_HEADER_MAGIC 0xF30A
+
+// Specified by ext4 docs and backed by a bunch of math
+#define EXT4_EXTENT_TREE_MAX_DEPTH 5
+
+typedef struct {
+ // CRC32C of UUID + inode number + igeneration + extent block
+ UINT32 eb_checksum;
+} EXT4_EXTENT_TAIL;
+
+typedef UINT64 EXT4_BLOCK_NR;
+typedef UINT32 EXT4_INO_NR;
+
+#define EXT4_INODE_SIZE(ino) (LShiftU64 (ino->i_size_hi, 32) | ino->i_size_lo)
+
+#endif
diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c
new file mode 100644
index 0000000000..62f73da9f7
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c
@@ -0,0 +1,789 @@
+/** @file Driver entry point
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mExt4DriverNameTable[] = {
+ {
+ "eng;en",
+ L"Ext4 File System Driver"
+ },
+ {
+ NULL,
+ NULL
+ }
+};
+
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_UNICODE_STRING_TABLE mExt4ControllerNameTable[] = {
+ {
+ "eng;en",
+ L"Ext4 File System"
+ },
+ {
+ NULL,
+ NULL
+ }
+};
+
+// Needed by gExt4ComponentName*
+
+/**
+ Retrieves a Unicode string that is the user-readable name of the EFI Driver.
+
+ @param This A pointer to the EFI_COMPONENT_NAME_PROTOCOL instance.
+ @param Language A pointer to a three-character ISO 639-2 language identifier.
+ This is the language of the driver name that that the caller
+ is requesting, and it must match one of the languages specified
+ in SupportedLanguages. The number of languages supported by a
+ driver is up to the driver writer.
+ @param DriverName A pointer to the Unicode string to return. This Unicode string
+ is the name of the driver specified by This in the language
+ specified by Language.
+
+ @retval EFI_SUCCESS The Unicode string for the Driver specified by This
+ and the language specified by Language was returned
+ in DriverName.
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+ @retval EFI_INVALID_PARAMETER DriverName is NULL.
+ @retval EFI_UNSUPPORTED The driver specified by This does not support the
+ language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ComponentNameGetDriverName (
+ IN EFI_COMPONENT_NAME_PROTOCOL *This,
+ IN CHAR8 *Language,
+ OUT CHAR16 **DriverName
+ );
+
+/**
+ Retrieves a Unicode string that is the user readable name of the controller
+ that is being managed by an EFI Driver.
+
+ @param This A pointer to the EFI_COMPONENT_NAME_PROTOCOL instance.
+ @param ControllerHandle The handle of a controller that the driver specified by
+ This is managing. This handle specifies the controller
+ whose name is to be returned.
+ @param ChildHandle The handle of the child controller to retrieve the name
+ of. This is an optional parameter that may be NULL. It
+ will be NULL for device drivers. It will also be NULL
+ for a bus drivers that wish to retrieve the name of the
+ bus controller. It will not be NULL for a bus driver
+ that wishes to retrieve the name of a child controller.
+ @param Language A pointer to a three character ISO 639-2 language
+ identifier. This is the language of the controller name
+ that the caller is requesting, and it must match one
+ of the languages specified in SupportedLanguages. The
+ number of languages supported by a driver is up to the
+ driver writer.
+ @param ControllerName A pointer to the Unicode string to return. This Unicode
+ string is the name of the controller specified by
+ ControllerHandle and ChildHandle in the language specified
+ by Language, from the point of view of the driver specified
+ by This.
+
+ @retval EFI_SUCCESS The Unicode string for the user-readable name in the
+ language specified by Language for the driver
+ specified by This was returned in DriverName.
+ @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
+ @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid EFI_HANDLE.
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+ @retval EFI_INVALID_PARAMETER ControllerName is NULL.
+ @retval EFI_UNSUPPORTED The driver specified by This is not currently managing
+ the controller specified by ControllerHandle and
+ ChildHandle.
+ @retval EFI_UNSUPPORTED The driver specified by This does not support the
+ language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ComponentNameGetControllerName (
+ IN EFI_COMPONENT_NAME_PROTOCOL *This,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_HANDLE ChildHandle OPTIONAL,
+ IN CHAR8 *Language,
+ OUT CHAR16 **ControllerName
+ );
+
+extern EFI_COMPONENT_NAME_PROTOCOL gExt4ComponentName;
+
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME_PROTOCOL gExt4ComponentName = {
+ Ext4ComponentNameGetDriverName,
+ Ext4ComponentNameGetControllerName,
+ "eng"
+};
+
+//
+// EFI Component Name 2 Protocol
+//
+GLOBAL_REMOVE_IF_UNREFERENCED EFI_COMPONENT_NAME2_PROTOCOL gExt4ComponentName2 = {
+ (EFI_COMPONENT_NAME2_GET_DRIVER_NAME)Ext4ComponentNameGetDriverName,
+ (EFI_COMPONENT_NAME2_GET_CONTROLLER_NAME)Ext4ComponentNameGetControllerName,
+ "en"
+};
+
+// Needed by gExt4BindingProtocol
+
+/**
+ Tests to see if this driver supports a given controller. If a child device is provided,
+ it further tests to see if this driver supports creating a handle for the specified child device.
+
+ This function checks to see if the driver specified by This supports the device specified by
+ ControllerHandle. Drivers will typically use the device path attached to
+ ControllerHandle and/or the services from the bus I/O abstraction attached to
+ ControllerHandle to determine if the driver supports ControllerHandle. This function
+ may be called many times during platform initialization. In order to reduce boot times, the tests
+ performed by this function must be very small, and take as little time as possible to execute. This
+ function must not change the state of any hardware devices, and this function must be aware that the
+ device specified by ControllerHandle may already be managed by the same driver or a
+ different driver. This function must match its calls to AllocatePages() with FreePages(),
+ AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
+ Because ControllerHandle may have been previously started by the same driver, if a protocol is
+ already in the opened state, then it must not be closed with CloseProtocol(). This is required
+ to guarantee the state of ControllerHandle is not modified by this function.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to test. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For bus drivers, if this parameter is not NULL, then
+ the bus driver must determine if the bus controller specified
+ by ControllerHandle and the child controller specified
+ by RemainingDevicePath are both supported by this
+ bus driver.
+
+ @retval EFI_SUCCESS The device specified by ControllerHandle and
+ RemainingDevicePath is supported by the driver specified by This.
+ @retval EFI_ALREADY_STARTED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by the driver
+ specified by This.
+ @retval EFI_ACCESS_DENIED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by a different
+ driver or an application that requires exclusive access.
+ Currently not implemented.
+ @retval EFI_UNSUPPORTED The device specified by ControllerHandle and
+ RemainingDevicePath is not supported by the driver specified by This.
+**/
+EFI_STATUS EFIAPI
+Ext4IsBindingSupported (
+ IN EFI_DRIVER_BINDING_PROTOCOL *BindingProtocol,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_DEVICE_PATH *RemainingDevicePath OPTIONAL
+ );
+
+/**
+ Starts a device controller or a bus controller.
+
+ The Start() function is designed to be invoked from the EFI boot service ConnectController().
+ As a result, much of the error checking on the parameters to Start() has been moved into this
+ common boot service. It is legal to call Start() from other locations,
+ but the following calling restrictions must be followed, or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE.
+ 2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
+ EFI_DEVICE_PATH_PROTOCOL.
+ 3. Prior to calling Start(), the Supported() function for the driver specified by This must
+ have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to start. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For a bus driver, if this parameter is NULL, then handles
+ for all the children of Controller are created by this driver.
+ If this parameter is not NULL and the first Device Path Node is
+ not the End of Device Path Node, then only the handle for the
+ child device specified by the first Device Path Node of
+ RemainingDevicePath is created by this driver.
+ If the first Device Path Node of RemainingDevicePath is
+ the End of Device Path Node, no child handle is created by this
+ driver.
+
+ @retval EFI_SUCCESS The device was started.
+ @retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.
+ @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.
+ @retval Others The driver failded to start the device.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Bind (
+ IN EFI_DRIVER_BINDING_PROTOCOL *BindingProtocol,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_DEVICE_PATH *RemainingDevicePath OPTIONAL
+ );
+
+/**
+ Stops a device controller or a bus controller.
+
+ The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
+ As a result, much of the error checking on the parameters to Stop() has been moved
+ into this common boot service. It is legal to call Stop() from other locations,
+ but the following calling restrictions must be followed, or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
+ same driver's Start() function.
+ 2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
+ EFI_HANDLE. In addition, all of these handles must have been created in this driver's
+ Start() function, and the Start() function must have called OpenProtocol() on
+ ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle A handle to the device being stopped. The handle must
+ support a bus specific I/O protocol for the driver
+ to use to stop the device.
+ @param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.
+ @param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL
+ if NumberOfChildren is 0.
+
+ @retval EFI_SUCCESS The device was stopped.
+ @retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Stop (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE ControllerHandle,
+ IN UINTN NumberOfChildren,
+ IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
+ );
+
+EFI_DRIVER_BINDING_PROTOCOL gExt4BindingProtocol =
+{
+ Ext4IsBindingSupported,
+ Ext4Bind,
+ Ext4Stop,
+ EXT4_DRIVER_VERSION
+};
+
+/**
+ Retrieves a Unicode string that is the user readable name of the controller
+ that is being managed by an EFI Driver.
+
+ @param This A pointer to the EFI_COMPONENT_NAME_PROTOCOL instance.
+ @param ControllerHandle The handle of a controller that the driver specified by
+ This is managing. This handle specifies the controller
+ whose name is to be returned.
+ @param ChildHandle The handle of the child controller to retrieve the name
+ of. This is an optional parameter that may be NULL. It
+ will be NULL for device drivers. It will also be NULL
+ for a bus drivers that wish to retrieve the name of the
+ bus controller. It will not be NULL for a bus driver
+ that wishes to retrieve the name of a child controller.
+ @param Language A pointer to a three character ISO 639-2 language
+ identifier. This is the language of the controller name
+ that the caller is requesting, and it must match one
+ of the languages specified in SupportedLanguages. The
+ number of languages supported by a driver is up to the
+ driver writer.
+ @param ControllerName A pointer to the Unicode string to return. This Unicode
+ string is the name of the controller specified by
+ ControllerHandle and ChildHandle in the language specified
+ by Language, from the point of view of the driver specified
+ by This.
+
+ @retval EFI_SUCCESS The Unicode string for the user-readable name in the
+ language specified by Language for the driver
+ specified by This was returned in DriverName.
+ @retval EFI_INVALID_PARAMETER ControllerHandle is NULL.
+ @retval EFI_INVALID_PARAMETER ChildHandle is not NULL and it is not a valid EFI_HANDLE.
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+ @retval EFI_INVALID_PARAMETER ControllerName is NULL.
+ @retval EFI_UNSUPPORTED The driver specified by This is not currently managing
+ the controller specified by ControllerHandle and
+ ChildHandle.
+ @retval EFI_UNSUPPORTED The driver specified by This does not support the
+ language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ComponentNameGetControllerName (
+ IN EFI_COMPONENT_NAME_PROTOCOL *This,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_HANDLE ChildHandle OPTIONAL,
+ IN CHAR8 *Language,
+ OUT CHAR16 **ControllerName
+ )
+{
+ // TODO: Do we need to test whether we're managing the handle, like FAT does?
+ return LookupUnicodeString2 (
+ Language,
+ This->SupportedLanguages,
+ mExt4ControllerNameTable,
+ ControllerName,
+ (BOOLEAN)(This == &gExt4ComponentName)
+ );
+}
+
+/**
+ Retrieves a Unicode string that is the user-readable name of the EFI Driver.
+
+ @param This A pointer to the EFI_COMPONENT_NAME_PROTOCOL instance.
+ @param Language A pointer to a three-character ISO 639-2 language identifier.
+ This is the language of the driver name that that the caller
+ is requesting, and it must match one of the languages specified
+ in SupportedLanguages. The number of languages supported by a
+ driver is up to the driver writer.
+ @param DriverName A pointer to the Unicode string to return. This Unicode string
+ is the name of the driver specified by This in the language
+ specified by Language.
+
+ @retval EFI_SUCCESS The Unicode string for the Driver specified by This
+ and the language specified by Language was returned
+ in DriverName.
+ @retval EFI_INVALID_PARAMETER Language is NULL.
+ @retval EFI_INVALID_PARAMETER DriverName is NULL.
+ @retval EFI_UNSUPPORTED The driver specified by This does not support the
+ language specified by Language.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ComponentNameGetDriverName (
+ IN EFI_COMPONENT_NAME_PROTOCOL *This,
+ IN CHAR8 *Language,
+ OUT CHAR16 **DriverName
+ )
+{
+ return LookupUnicodeString2 (
+ Language,
+ This->SupportedLanguages,
+ mExt4DriverNameTable,
+ DriverName,
+ (BOOLEAN)(This == &gExt4ComponentName)
+ );
+}
+
+/**
+ Stops a device controller or a bus controller.
+
+ The Stop() function is designed to be invoked from the EFI boot service DisconnectController().
+ As a result, much of the error checking on the parameters to Stop() has been moved
+ into this common boot service. It is legal to call Stop() from other locations,
+ but the following calling restrictions must be followed, or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE that was used on a previous call to this
+ same driver's Start() function.
+ 2. The first NumberOfChildren handles of ChildHandleBuffer must all be a valid
+ EFI_HANDLE. In addition, all of these handles must have been created in this driver's
+ Start() function, and the Start() function must have called OpenProtocol() on
+ ControllerHandle with an Attribute of EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle A handle to the device being stopped. The handle must
+ support a bus specific I/O protocol for the driver
+ to use to stop the device.
+ @param[in] NumberOfChildren The number of child device handles in ChildHandleBuffer.
+ @param[in] ChildHandleBuffer An array of child handles to be freed. May be NULL
+ if NumberOfChildren is 0.
+
+ @retval EFI_SUCCESS The device was stopped.
+ @retval EFI_DEVICE_ERROR The device could not be stopped due to a device error.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Stop (
+ IN EFI_DRIVER_BINDING_PROTOCOL *This,
+ IN EFI_HANDLE ControllerHandle,
+ IN UINTN NumberOfChildren,
+ IN EFI_HANDLE *ChildHandleBuffer OPTIONAL
+ )
+{
+ EFI_STATUS Status;
+ EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *Sfs;
+ EXT4_PARTITION *Partition;
+ BOOLEAN HasDiskIo2;
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiSimpleFileSystemProtocolGuid,
+ (VOID **)&Sfs,
+ This->DriverBindingHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Partition = (EXT4_PARTITION *)Sfs;
+
+ HasDiskIo2 = Ext4DiskIo2 (Partition) != NULL;
+
+ Status = Ext4UnmountAndFreePartition (Partition);
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = gBS->UninstallMultipleProtocolInterfaces (
+ ControllerHandle,
+ &gEfiSimpleFileSystemProtocolGuid,
+ &Partition->Interface,
+ NULL
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ // Close all open protocols (DiskIo, DiskIo2, BlockIo)
+
+ Status = gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiDiskIoProtocolGuid,
+ This->DriverBindingHandle,
+ ControllerHandle
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiBlockIoProtocolGuid,
+ This->DriverBindingHandle,
+ ControllerHandle
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ if(HasDiskIo2) {
+ Status = gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiDiskIo2ProtocolGuid,
+ This->DriverBindingHandle,
+ ControllerHandle
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+ }
+
+ return Status;
+}
+
+/**
+ Ext4Dxe Driver's entry point.
+
+ Called at load time.
+
+ @param[in] ImageHandle Handle to the image.
+ @param[in] SystemTable Pointer to the EFI_SYSTEM_TABLE.
+ @return Result of the load.
+**/
+EFI_STATUS
+EFIAPI
+Ext4EntryPoint (
+ IN EFI_HANDLE ImageHandle,
+ IN EFI_SYSTEM_TABLE *SystemTable
+ )
+{
+ EFI_STATUS Status;
+
+ Status = EfiLibInstallAllDriverProtocols2 (
+ ImageHandle,
+ SystemTable,
+ &gExt4BindingProtocol,
+ ImageHandle,
+ &gExt4ComponentName,
+ &gExt4ComponentName2,
+ NULL,
+ NULL,
+ NULL,
+ NULL
+ );
+
+ if(EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ return Ext4InitialiseUnicodeCollation (ImageHandle);
+}
+
+/**
+ Ext4Dxe Driver's unload callback.
+
+ Called at unload time.
+
+ @param[in] ImageHandle Handle to the image.
+ @return Result of the unload.
+**/
+EFI_STATUS
+EFIAPI
+Ext4Unload (
+ IN EFI_HANDLE ImageHandle
+ )
+{
+ EFI_STATUS Status;
+ EFI_HANDLE *DeviceHandleBuffer;
+ UINTN DeviceHandleCount;
+ UINTN Index;
+
+ Status = gBS->LocateHandleBuffer (
+ AllHandles,
+ NULL,
+ NULL,
+ &DeviceHandleCount,
+ &DeviceHandleBuffer
+ );
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ for(Index = 0; Index < DeviceHandleCount; Index++) {
+ EFI_HANDLE Handle;
+
+ Handle = DeviceHandleBuffer[Index];
+
+ Status = EfiTestManagedDevice (Handle, ImageHandle, &gEfiDiskIoProtocolGuid);
+
+ if(Status == EFI_SUCCESS) {
+ Status = gBS->DisconnectController (Handle, ImageHandle, NULL);
+
+ if (EFI_ERROR (Status)) {
+ break;
+ }
+ }
+ }
+
+ FreePool (DeviceHandleBuffer);
+
+ Status = EfiLibUninstallAllDriverProtocols2 (
+ &gExt4BindingProtocol,
+ &gExt4ComponentName,
+ &gExt4ComponentName2,
+ NULL,
+ NULL,
+ NULL,
+ NULL
+ );
+
+ return Status;
+}
+
+/**
+ Tests to see if this driver supports a given controller. If a child device is provided,
+ it further tests to see if this driver supports creating a handle for the specified child device.
+
+ This function checks to see if the driver specified by This supports the device specified by
+ ControllerHandle. Drivers will typically use the device path attached to
+ ControllerHandle and/or the services from the bus I/O abstraction attached to
+ ControllerHandle to determine if the driver supports ControllerHandle. This function
+ may be called many times during platform initialization. In order to reduce boot times, the tests
+ performed by this function must be very small, and take as little time as possible to execute. This
+ function must not change the state of any hardware devices, and this function must be aware that the
+ device specified by ControllerHandle may already be managed by the same driver or a
+ different driver. This function must match its calls to AllocatePages() with FreePages(),
+ AllocatePool() with FreePool(), and OpenProtocol() with CloseProtocol().
+ Because ControllerHandle may have been previously started by the same driver, if a protocol is
+ already in the opened state, then it must not be closed with CloseProtocol(). This is required
+ to guarantee the state of ControllerHandle is not modified by this function.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to test. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For bus drivers, if this parameter is not NULL, then
+ the bus driver must determine if the bus controller specified
+ by ControllerHandle and the child controller specified
+ by RemainingDevicePath are both supported by this
+ bus driver.
+
+ @retval EFI_SUCCESS The device specified by ControllerHandle and
+ RemainingDevicePath is supported by the driver specified by This.
+ @retval EFI_ALREADY_STARTED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by the driver
+ specified by This.
+ @retval EFI_ACCESS_DENIED The device specified by ControllerHandle and
+ RemainingDevicePath is already being managed by a different
+ driver or an application that requires exclusive access.
+ Currently not implemented.
+ @retval EFI_UNSUPPORTED The device specified by ControllerHandle and
+ RemainingDevicePath is not supported by the driver specified by This.
+**/
+EFI_STATUS EFIAPI
+Ext4IsBindingSupported (
+ IN EFI_DRIVER_BINDING_PROTOCOL *BindingProtocol,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_DEVICE_PATH *RemainingDevicePath OPTIONAL
+ )
+{
+ // Note to self: EFI_OPEN_PROTOCOL_TEST_PROTOCOL lets us not close the
+ // protocol and ignore the output argument entirely
+
+ EFI_STATUS Status;
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiDiskIoProtocolGuid,
+ NULL,
+ BindingProtocol->ImageHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_TEST_PROTOCOL
+ );
+
+ if(EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiBlockIoProtocolGuid,
+ NULL,
+ BindingProtocol->ImageHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_TEST_PROTOCOL
+ );
+ return Status;
+}
+
+/**
+ Starts a device controller or a bus controller.
+
+ The Start() function is designed to be invoked from the EFI boot service ConnectController().
+ As a result, much of the error checking on the parameters to Start() has been moved into this
+ common boot service. It is legal to call Start() from other locations,
+ but the following calling restrictions must be followed, or the system behavior will not be deterministic.
+ 1. ControllerHandle must be a valid EFI_HANDLE.
+ 2. If RemainingDevicePath is not NULL, then it must be a pointer to a naturally aligned
+ EFI_DEVICE_PATH_PROTOCOL.
+ 3. Prior to calling Start(), the Supported() function for the driver specified by This must
+ have been called with the same calling parameters, and Supported() must have returned EFI_SUCCESS.
+
+ @param[in] This A pointer to the EFI_DRIVER_BINDING_PROTOCOL instance.
+ @param[in] ControllerHandle The handle of the controller to start. This handle
+ must support a protocol interface that supplies
+ an I/O abstraction to the driver.
+ @param[in] RemainingDevicePath A pointer to the remaining portion of a device path. This
+ parameter is ignored by device drivers, and is optional for bus
+ drivers. For a bus driver, if this parameter is NULL, then handles
+ for all the children of Controller are created by this driver.
+ If this parameter is not NULL and the first Device Path Node is
+ not the End of Device Path Node, then only the handle for the
+ child device specified by the first Device Path Node of
+ RemainingDevicePath is created by this driver.
+ If the first Device Path Node of RemainingDevicePath is
+ the End of Device Path Node, no child handle is created by this
+ driver.
+
+ @retval EFI_SUCCESS The device was started.
+ @retval EFI_DEVICE_ERROR The device could not be started due to a device error.Currently not implemented.
+ @retval EFI_OUT_OF_RESOURCES The request could not be completed due to a lack of resources.
+ @retval Others The driver failded to start the device.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Bind (
+ IN EFI_DRIVER_BINDING_PROTOCOL *BindingProtocol,
+ IN EFI_HANDLE ControllerHandle,
+ IN EFI_DEVICE_PATH *RemainingDevicePath OPTIONAL
+ )
+{
+ EFI_DISK_IO_PROTOCOL *DiskIo;
+ EFI_DISK_IO2_PROTOCOL *DiskIo2;
+ EFI_BLOCK_IO_PROTOCOL *BlockIo;
+ EFI_STATUS Status;
+
+ DiskIo2 = NULL;
+ BlockIo = NULL;
+ DiskIo = NULL;
+
+ DEBUG ((DEBUG_INFO, "[Ext4] Binding to controller\n"));
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiDiskIoProtocolGuid,
+ (VOID **)&DiskIo,
+ BindingProtocol->ImageHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+
+ if(EFI_ERROR (Status)) {
+ goto Error;
+ }
+
+ DEBUG ((DEBUG_INFO, "[Ext4] Controller supports DISK_IO\n"));
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiDiskIo2ProtocolGuid,
+ (VOID **)&DiskIo2,
+ BindingProtocol->ImageHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_BY_DRIVER
+ );
+ // It's okay to not support DISK_IO2
+
+ if(DiskIo2 != NULL) {
+ DEBUG ((DEBUG_INFO, "[Ext4] Controller supports DISK_IO2\n"));
+ }
+
+ Status = gBS->OpenProtocol (
+ ControllerHandle,
+ &gEfiBlockIoProtocolGuid,
+ (VOID **)&BlockIo,
+ BindingProtocol->ImageHandle,
+ ControllerHandle,
+ EFI_OPEN_PROTOCOL_GET_PROTOCOL
+ );
+
+ if(EFI_ERROR (Status)) {
+ goto Error;
+ }
+
+ DEBUG ((DEBUG_INFO, "Opening partition\n"));
+
+ Status = Ext4OpenPartition (ControllerHandle, DiskIo, DiskIo2, BlockIo);
+
+ if(EFI_ERROR (Status)) {
+ DEBUG ((DEBUG_INFO, "[ext4] Error mounting %r\n", Status));
+ // Falls through to Error
+ } else {
+ return Status;
+ }
+
+Error:
+ if(DiskIo) {
+ gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiDiskIoProtocolGuid,
+ BindingProtocol->ImageHandle,
+ ControllerHandle
+ );
+ }
+
+ if(DiskIo2) {
+ gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiDiskIo2ProtocolGuid,
+ BindingProtocol->ImageHandle,
+ ControllerHandle
+ );
+ }
+
+ if(BlockIo) {
+ gBS->CloseProtocol (
+ ControllerHandle,
+ &gEfiBlockIoProtocolGuid,
+ BindingProtocol->ImageHandle,
+ ControllerHandle
+ );
+ }
+
+ return Status;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h
new file mode 100644
index 0000000000..ba5ff5a35d
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h
@@ -0,0 +1,1136 @@
+/** @file Common header for the driver
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef EXT4_H_
+#define EXT4_H_
+
+#include <Uefi.h>
+
+#include <Guid/FileInfo.h>
+#include <Guid/FileSystemInfo.h>
+#include <Guid/FileSystemVolumeLabelInfo.h>
+#include <Protocol/BlockIo.h>
+#include <Protocol/DiskIo.h>
+#include <Protocol/DiskIo2.h>
+#include <Protocol/SimpleFileSystem.h>
+
+#include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
+#include <Library/UefiLib.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <Library/UefiDriverEntryPoint.h>
+#include <Library/UefiBootServicesTableLib.h>
+#include <Library/UefiRuntimeServicesTableLib.h>
+#include <Library/OrderedCollectionLib.h>
+
+#include "Ext4Disk.h"
+
+#define EXT4_NAME_MAX 255
+
+#define EXT4_DRIVER_VERSION 0x0000
+
+/**
+ Opens an ext4 partition and installs the Simple File System protocol.
+
+ @param[in] DeviceHandle Handle to the block device.
+ @param[in] DiskIo Pointer to an EFI_DISK_IO_PROTOCOL.
+ @param[in opt] DiskIo2 Pointer to an EFI_DISK_IO2_PROTOCOL, if supported.
+ @param[in] BlockIo Pointer to an EFI_BLOCK_IO_PROTOCOL.
+
+ @retval EFI_SUCCESS The opening was successful.
+ !EFI_SUCCESS Opening failed.
+**/
+EFI_STATUS
+Ext4OpenPartition (
+ IN EFI_HANDLE DeviceHandle,
+ IN EFI_DISK_IO_PROTOCOL *DiskIo,
+ IN OPTIONAL EFI_DISK_IO2_PROTOCOL *DiskIo2,
+ IN EFI_BLOCK_IO_PROTOCOL *BlockIo
+ );
+
+typedef struct _Ext4File EXT4_FILE;
+
+typedef struct _Ext4_PARTITION {
+ EFI_SIMPLE_FILE_SYSTEM_PROTOCOL Interface;
+ EFI_DISK_IO_PROTOCOL *DiskIo;
+ EFI_DISK_IO2_PROTOCOL *DiskIo2;
+ EFI_BLOCK_IO_PROTOCOL *BlockIo;
+
+ EXT4_SUPERBLOCK SuperBlock;
+ BOOLEAN Unmounting;
+
+ UINT32 FeaturesIncompat;
+ UINT32 FeaturesCompat;
+ UINT32 FeaturesRoCompat;
+ UINT32 InodeSize;
+ UINT32 BlockSize;
+ BOOLEAN ReadOnly;
+ UINT64 NumberBlockGroups;
+ EXT4_BLOCK_NR NumberBlocks;
+
+ EXT4_BLOCK_GROUP_DESC *BlockGroups;
+ UINT32 DescSize;
+ EXT4_FILE *Root;
+
+ UINT32 InitialSeed;
+
+ LIST_ENTRY OpenFiles;
+} EXT4_PARTITION;
+
+/**
+ Opens and parses the superblock.
+
+ @param[out] Partition Partition structure to fill with filesystem details.
+ @retval EFI_SUCCESS Parsing was succesful and the partition is a
+ valid ext4 partition.
+**/
+EFI_STATUS
+Ext4OpenSuperblock (
+ OUT EXT4_PARTITION *Partition
+ );
+
+/**
+ Retrieves the EFI_BLOCK_IO_PROTOCOL of the partition.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @return The Block IO protocol associated with the partition.
+**/
+STATIC inline
+EFI_BLOCK_IO_PROTOCOL *
+Ext4BlockIo (
+ EXT4_PARTITION *Partition
+ )
+{
+ return Partition->BlockIo;
+}
+
+/**
+ Retrieves the EFI_DISK_IO_PROTOCOL of the partition.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @return The Disk IO protocol associated with the partition.
+**/
+STATIC inline
+EFI_DISK_IO_PROTOCOL *
+Ext4DiskIo (
+ EXT4_PARTITION *Partition
+ )
+{
+ return Partition->DiskIo;
+}
+
+/**
+ Retrieves the EFI_DISK_IO2_PROTOCOL of the partition.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @return The Disk IO 2 protocol associated with the partition, or NULL if
+ not supported.
+**/
+STATIC inline
+EFI_DISK_IO2_PROTOCOL *
+Ext4DiskIo2 (
+ EXT4_PARTITION *Partition
+ )
+{
+ return Partition->DiskIo2;
+}
+
+/**
+ Retrieves the media ID of the partition.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @return The media ID associated with the partition.
+**/
+STATIC inline
+UINT32
+Ext4MediaId (
+ EXT4_PARTITION *Partition
+ )
+{
+ return Partition->BlockIo->Media->MediaId;
+}
+
+/**
+ Reads from the partition's disk using the DISK_IO protocol.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[out] Buffer Pointer to a destination buffer.
+ @param[in] Length Length of the destination buffer.
+ @param[in] Offset Offset, in bytes, of the location to read.
+
+ @return Success status of the disk read.
+**/
+EFI_STATUS
+Ext4ReadDiskIo (
+ IN EXT4_PARTITION *Partition,
+ OUT VOID *Buffer,
+ IN UINTN Length,
+ IN UINT64 Offset
+ );
+
+/**
+ Reads blocks from the partition's disk using the DISK_IO protocol.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[out] Buffer Pointer to a destination buffer.
+ @param[in] NumberBlocks Length of the read, in filesystem blocks.
+ @param[in] BlockNumber Starting block number.
+
+ @return Success status of the read.
+**/
+EFI_STATUS
+Ext4ReadBlocks (
+ IN EXT4_PARTITION *Partition,
+ OUT VOID *Buffer,
+ IN UINTN NumberBlocks,
+ IN EXT4_BLOCK_NR BlockNumber
+ );
+
+/**
+ Allocates a buffer and reads blocks from the partition's disk using the DISK_IO protocol.
+ This function is deprecated and will be removed in the future.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[in] NumberBlocks Length of the read, in filesystem blocks.
+ @param[in] BlockNumber Starting block number.
+
+ @return Buffer allocated by AllocatePool, or NULL if some part of the process
+ failed.
+**/
+VOID *
+Ext4AllocAndReadBlocks (
+ IN EXT4_PARTITION *Partition,
+ IN UINTN NumberBlocks,
+ IN EXT4_BLOCK_NR BlockNumber
+ );
+
+/**
+ Checks if the opened partition has the 64-bit feature (see EXT4_FEATURE_INCOMPAT_64BIT).
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+
+ @return TRUE if EXT4_FEATURE_INCOMPAT_64BIT is enabled, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4Is64Bit (
+ IN CONST EXT4_PARTITION *Partition
+ )
+{
+ return Partition->FeaturesIncompat & EXT4_FEATURE_INCOMPAT_64BIT;
+}
+
+/**
+ Composes an EXT4_BLOCK_NR safely, from two halfs.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[in] Low Low half of the block number.
+ @param[in] High High half of the block number.
+
+ @return The block number formed by Low, and if 64 bit is enabled, High.
+**/
+STATIC inline
+EXT4_BLOCK_NR
+Ext4MakeBlockNumberFromHalfs (
+ IN CONST EXT4_PARTITION *Partition,
+ IN UINT32 Low,
+ IN UINT32 High
+ )
+{
+ // High might have garbage if it's not a 64 bit filesystem
+ return Ext4Is64Bit (Partition) ? (Low | LShiftU64 (High, 32)) : Low;
+}
+
+/**
+ Retrieves a block group descriptor of the ext4 filesystem.
+
+ @param[in] Partition Pointer to the opened ext4 partition.
+ @param[in] BlockGroup Block group number.
+
+ @return A pointer to the block group descriptor.
+**/
+STATIC inline
+EXT4_BLOCK_GROUP_DESC *
+Ext4GetBlockGroupDesc (
+ IN EXT4_PARTITION *Partition,
+ IN UINT32 BlockGroup
+ )
+{
+ // Maybe assert that the block group nr isn't a nonsense number?
+ return (EXT4_BLOCK_GROUP_DESC *)((CHAR8 *)Partition->BlockGroups + BlockGroup * Partition->DescSize);
+}
+
+/**
+ Reads an inode from disk.
+
+ @param[in] Partition Pointer to the opened partition.
+ @param[in] InodeNum Number of the desired Inode
+ @param[out] OutIno Pointer to where it will be stored a pointer to the read inode.
+
+ @return Status of the inode read.
+**/
+EFI_STATUS
+Ext4ReadInode (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_INO_NR InodeNum,
+ OUT EXT4_INODE **OutIno
+ );
+
+/**
+ Converts blocks to bytes.
+
+ @param[in] Partition Pointer to the opened partition.
+ @param[in] Block Block number/number of blocks.
+
+ @return The number of bytes.
+**/
+STATIC inline
+UINT64
+Ext4BlockToByteOffset (
+ IN CONST EXT4_PARTITION *Partition,
+ IN EXT4_BLOCK_NR Block
+ )
+{
+ return MultU64x32 (Block, Partition->BlockSize);
+}
+
+/**
+ Reads from an EXT4 inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] File Pointer to the opened file.
+ @param[out] Buffer Pointer to the buffer.
+ @param[in] Offset Offset of the read.
+ @param[in out] Length Pointer to the length of the buffer, in bytes.
+ After a succesful read, it's updated to the number of read bytes.
+
+ @return Status of the read operation.
+**/
+EFI_STATUS
+Ext4Read (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ OUT VOID *Buffer,
+ IN UINT64 Offset,
+ IN OUT UINTN *Length
+ );
+
+/**
+ Retrieves the size of the inode.
+
+ @param[in] Inode Pointer to the ext4 inode.
+
+ @return The size of the inode, in bytes.
+**/
+STATIC inline
+UINT64
+Ext4InodeSize (
+ CONST EXT4_INODE *Inode
+ )
+{
+ return (LShiftU64 (Inode->i_size_hi, 32) | Inode->i_size_lo);
+}
+
+/**
+ Retrieves an extent from an EXT4 inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] File Pointer to the opened file.
+ @param[in] LogicalBlock Block number which the returned extent must cover.
+ @param[out] Extent Pointer to the output buffer, where the extent will be copied to.
+
+ @retval EFI_SUCCESS Retrieval was succesful.
+ @retval EFI_NO_MAPPING Block has no mapping.
+**/
+EFI_STATUS
+Ext4GetExtent (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ IN EXT4_BLOCK_NR LogicalBlock,
+ OUT EXT4_EXTENT *Extent
+ );
+
+struct _Ext4File {
+ EFI_FILE_PROTOCOL Protocol;
+ EXT4_INODE *Inode;
+ EXT4_INO_NR InodeNum;
+
+ UINT64 OpenMode;
+ UINT64 Position;
+
+ EXT4_PARTITION *Partition;
+ CHAR16 *FileName;
+
+ ORDERED_COLLECTION *ExtentsMap;
+
+ LIST_ENTRY OpenFilesListNode;
+};
+
+#define EXT4_FILE_FROM_OPEN_FILES_NODE(Node) BASE_CR (Node, EXT4_FILE, OpenFilesListNode)
+
+/**
+ Retrieves a directory entry.
+
+ @param[in] Directory Pointer to the opened directory.
+ @param[in] NameUnicode Pointer to the UCS-2 formatted filename.
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[out] Result Pointer to the destination directory entry.
+
+ @return The result of the operation.
+**/
+EFI_STATUS
+Ext4RetrieveDirent (
+ IN EXT4_FILE *Directory,
+ IN CONST CHAR16 *NameUnicode,
+ IN EXT4_PARTITION *Partition,
+ OUT EXT4_DIR_ENTRY *Result
+ );
+
+/**
+ Opens a file.
+
+ @param[in] Directory Pointer to the opened directory.
+ @param[in] Name Pointer to the UCS-2 formatted filename.
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] OpenMode Mode in which the file is supposed to be open.
+ @param[out] OutFile Pointer to the newly opened file.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4OpenFile (
+ IN EXT4_FILE *Directory,
+ IN CONST CHAR16 *Name,
+ IN EXT4_PARTITION *Partition,
+ IN UINT64 OpenMode,
+ OUT EXT4_FILE **OutFile
+ );
+
+/**
+ Opens a file using a directory entry.
+
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] OpenMode Mode in which the file is supposed to be open.
+ @param[out] OutFile Pointer to the newly opened file.
+ @param[in] Entry Directory entry to be used.
+
+ @retval EFI_STATUS Result of the operation
+**/
+EFI_STATUS
+Ext4OpenDirent (
+ IN EXT4_PARTITION *Partition,
+ IN UINT64 OpenMode,
+ OUT EXT4_FILE **OutFile,
+ IN EXT4_DIR_ENTRY *Entry
+ );
+
+/**
+ Allocates a zeroed inode structure.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+
+ @return Pointer to the allocated structure, from the pool,
+ with size Partition->InodeSize.
+**/
+EXT4_INODE *
+Ext4AllocateInode (
+ IN EXT4_PARTITION *Partition
+ );
+
+// Part of the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
+
+/**
+ Open the root directory on a volume.
+
+ @param This A pointer to the volume to open the root directory.
+ @param Root A pointer to the location to return the opened file handle for the
+ root directory.
+
+ @retval EFI_SUCCESS The device was opened.
+ @retval EFI_UNSUPPORTED This volume does not support the requested file system type.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_ACCESS_DENIED The service denied access to the file.
+ @retval EFI_OUT_OF_RESOURCES The volume was not opened due to lack of resources.
+ @retval EFI_MEDIA_CHANGED The device has a different medium in it or the medium is no
+ longer supported. Any existing file handles for this volume are
+ no longer valid. To access the files on the new medium, the
+ volume must be reopened with OpenVolume().
+
+**/
+EFI_STATUS EFIAPI
+Ext4OpenVolume (
+ IN EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *This,
+ IN EFI_FILE_PROTOCOL **Root
+ );
+
+// End of EFI_SIMPLE_FILE_SYSTEM_PROTOCOL
+
+/**
+ Sets up the protocol and metadata of a file that is being opened.
+
+ @param[in out] File Pointer to the file.
+ @param[in] Partition Pointer to the opened partition.
+**/
+VOID
+Ext4SetupFile (
+ IN OUT EXT4_FILE *File,
+ IN EXT4_PARTITION *Partition
+ );
+
+/**
+ Closes a file.
+
+ @param[in] File Pointer to the file.
+
+ @return Status of the closing of the file.
+**/
+EFI_STATUS
+Ext4CloseInternal (
+ IN EXT4_FILE *File
+ );
+
+// Part of the EFI_FILE_PROTOCOL
+
+/**
+ Opens a new file relative to the source file's location.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to the source location. This would typically be an open
+ handle to a directory.
+ @param NewHandle A pointer to the location to return the opened handle for the new
+ file.
+ @param FileName The Null-terminated string of the name of the file to be opened.
+ The file name may contain the following path modifiers: "\", ".",
+ and "..".
+ @param OpenMode The mode to open the file. The only valid combinations that the
+ file may be opened with are: Read, Read/Write, or Create/Read/Write.
+ @param Attributes Only valid for EFI_FILE_MODE_CREATE, in which case these are the
+ attribute bits for the newly created file.
+
+ @retval EFI_SUCCESS The file was opened.
+ @retval EFI_NOT_FOUND The specified file could not be found on the device.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_MEDIA_CHANGED The device has a different medium in it or the medium is no
+ longer supported.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED An attempt was made to create a file, or open a file for write
+ when the media is write-protected.
+ @retval EFI_ACCESS_DENIED The service denied access to the file.
+ @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
+ @retval EFI_VOLUME_FULL The volume is full.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Open (
+ IN EFI_FILE_PROTOCOL *This,
+ OUT EFI_FILE_PROTOCOL **NewHandle,
+ IN CHAR16 *FileName,
+ IN UINT64 OpenMode,
+ IN UINT64 Attributes
+ );
+
+/**
+ Closes a specified file handle.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to close.
+
+ @retval EFI_SUCCESS The file was closed.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Close (
+ IN EFI_FILE_PROTOCOL *This
+ );
+
+/**
+ Close and delete the file handle.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the
+ handle to the file to delete.
+
+ @retval EFI_SUCCESS The file was closed and deleted, and the handle was closed.
+ @retval EFI_WARN_DELETE_FAILURE The handle was closed, but the file was not deleted.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Delete (
+ IN EFI_FILE_PROTOCOL *This
+ );
+
+/**
+ Reads data from a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to read data from.
+ @param BufferSize On input, the size of the Buffer. On output, the amount of data
+ returned in Buffer. In both cases, the size is measured in bytes.
+ @param Buffer The buffer into which the data is read.
+
+ @retval EFI_SUCCESS Data was read.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_DEVICE_ERROR An attempt was made to read from a deleted file.
+ @retval EFI_DEVICE_ERROR On entry, the current file position is beyond the end of the file.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory
+ entry. BufferSize has been updated with the size
+ needed to complete the request.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ReadFile (
+ IN EFI_FILE_PROTOCOL *This,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ );
+
+/**
+ Writes data to a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to write data to.
+ @param BufferSize On input, the size of the Buffer. On output, the amount of data
+ actually written. In both cases, the size is measured in bytes.
+ @param Buffer The buffer of data to write.
+
+ @retval EFI_SUCCESS Data was written.
+ @retval EFI_UNSUPPORTED Writes to open directory files are not supported.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_DEVICE_ERROR An attempt was made to write to a deleted file.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED The file or medium is write-protected.
+ @retval EFI_ACCESS_DENIED The file was opened read only.
+ @retval EFI_VOLUME_FULL The volume is full.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4WriteFile (
+ IN EFI_FILE_PROTOCOL *This,
+ IN OUT UINTN *BufferSize,
+ IN VOID *Buffer
+ );
+
+/**
+ Returns a file's current position.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to get the current position on.
+ @param Position The address to return the file's current position value.
+
+ @retval EFI_SUCCESS The position was returned.
+ @retval EFI_UNSUPPORTED The request is not valid on open directories.
+ @retval EFI_DEVICE_ERROR An attempt was made to get the position from a deleted file.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4GetPosition (
+ IN EFI_FILE_PROTOCOL *This,
+ OUT UINT64 *Position
+ );
+
+/**
+ Sets a file's current position.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the
+ file handle to set the requested position on.
+ @param Position The byte position from the start of the file to set.
+
+ @retval EFI_SUCCESS The position was set.
+ @retval EFI_UNSUPPORTED The seek request for nonzero is not valid on open
+ directories.
+ @retval EFI_DEVICE_ERROR An attempt was made to set the position of a deleted file.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4SetPosition (
+ IN EFI_FILE_PROTOCOL *This,
+ IN UINT64 Position
+ );
+
+/**
+ Returns information about a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle the requested information is for.
+ @param InformationType The type identifier for the information being requested.
+ @param BufferSize On input, the size of Buffer. On output, the amount of data
+ returned in Buffer. In both cases, the size is measured in bytes.
+ @param Buffer A pointer to the data buffer to return. The buffer's type is
+ indicated by InformationType.
+
+ @retval EFI_SUCCESS The information was returned.
+ @retval EFI_UNSUPPORTED The InformationType is not known.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory entry.
+ BufferSize has been updated with the size needed to complete
+ the request.
+**/
+EFI_STATUS
+EFIAPI
+Ext4GetInfo (
+ IN EFI_FILE_PROTOCOL *This,
+ IN EFI_GUID *InformationType,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ );
+
+/**
+ Sets information about a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle the information is for.
+ @param InformationType The type identifier for the information being set.
+ @param BufferSize The size, in bytes, of Buffer.
+ @param Buffer A pointer to the data buffer to write. The buffer's type is
+ indicated by InformationType.
+
+ @retval EFI_SUCCESS The information was set.
+ @retval EFI_UNSUPPORTED The InformationType is not known.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_INFO_ID and the media is
+ read-only.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_PROTOCOL_SYSTEM_INFO_ID
+ and the media is read only.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_SYSTEM_VOLUME_LABEL_ID
+ and the media is read-only.
+ @retval EFI_ACCESS_DENIED An attempt is made to change the name of a file to a
+ file that is already present.
+ @retval EFI_ACCESS_DENIED An attempt is being made to change the EFI_FILE_DIRECTORY
+ Attribute.
+ @retval EFI_ACCESS_DENIED An attempt is being made to change the size of a directory.
+ @retval EFI_ACCESS_DENIED InformationType is EFI_FILE_INFO_ID and the file was opened
+ read-only and an attempt is being made to modify a field
+ other than Attribute.
+ @retval EFI_VOLUME_FULL The volume is full.
+ @retval EFI_BAD_BUFFER_SIZE BufferSize is smaller than the size of the type indicated
+ by InformationType.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4SetInfo (
+ IN EFI_FILE_PROTOCOL *This,
+ IN EFI_GUID *InformationType,
+ IN UINTN BufferSize,
+ IN VOID *Buffer
+ );
+
+// EFI_FILE_PROTOCOL implementation ends here.
+
+/**
+ Checks if a file is a directory.
+ @param[in] File Pointer to the opened file.
+
+ @return TRUE if file is a directory.
+**/
+BOOLEAN
+Ext4FileIsDir (
+ IN CONST EXT4_FILE *File
+ );
+
+/**
+ Checks if a file is a regular file.
+ @param[in] File Pointer to the opened file.
+
+ @return BOOLEAN TRUE if file is a regular file.
+**/
+BOOLEAN
+Ext4FileIsReg (
+ IN CONST EXT4_FILE *File
+ );
+
+// In EFI we can't open FIFO pipes, UNIX sockets, character/block devices since these concepts are
+// at the kernel level and are OS dependent.
+
+/**
+ Checks if a file is openable.
+ @param[in] File Pointer to the file trying to be opened.
+
+
+ @return TRUE if file is openable. A file is considered openable if
+ it's a regular file or a directory, since most other file types
+ don't make sense under UEFI.
+**/
+STATIC inline
+BOOLEAN
+Ext4FileIsOpenable (
+ IN CONST EXT4_FILE *File
+ )
+{
+ return Ext4FileIsReg (File) || Ext4FileIsDir (File);
+}
+
+#define EXT4_INODE_HAS_FIELD(Inode, \
+ Field) (Inode->i_extra_isize + EXT4_GOOD_OLD_INODE_SIZE >= OFFSET_OF (EXT4_INODE, Field) + \
+ sizeof (((EXT4_INODE *)NULL)->Field))
+
+/**
+ Calculates the physical space used by a file.
+ @param[in] File Pointer to the opened file.
+
+ @return Physical space used by a file, in bytes.
+**/
+UINT64
+Ext4FilePhysicalSpace (
+ EXT4_FILE *File
+ );
+
+/**
+ Gets the file's last access time.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+**/
+VOID
+Ext4FileATime (
+ IN EXT4_FILE *File,
+ OUT EFI_TIME *Time
+ );
+
+/**
+ Gets the file's last (data) modification time.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+**/
+VOID
+Ext4FileMTime (
+ IN EXT4_FILE *File,
+ OUT EFI_TIME *Time
+ );
+
+/**
+ Gets the file's creation time, if possible.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+ In the case where the the creation time isn't recorded,
+ Time is zeroed.
+**/
+VOID
+Ext4FileCreateTime (
+ IN EXT4_FILE *File, OUT EFI_TIME *Time
+ );
+
+/**
+ Initialises Unicode collation, which is needed for case-insensitive string comparisons
+ within the driver (a good example of an application of this is filename comparison).
+
+ @param[in] DriverHandle Handle to the driver image.
+
+ @retval EFI_SUCCESS Unicode collation was successfully initialised.
+ @retval !EFI_SUCCESS Failure.
+**/
+EFI_STATUS
+Ext4InitialiseUnicodeCollation (
+ EFI_HANDLE DriverHandle
+ );
+
+/**
+ Does a case-insensitive string comparison. Refer to EFI_UNICODE_COLLATION_PROTOCOL's StriColl
+ for more details.
+
+ @param[in] Str1 Pointer to a null terminated string.
+ @param[in] Str2 Pointer to a null terminated string.
+
+ @retval 0 Str1 is equivalent to Str2.
+ @retval >0 Str1 is lexically greater than Str2.
+ @retval <0 Str1 is lexically less than Str2.
+**/
+INTN
+Ext4StrCmpInsensitive (
+ IN CHAR16 *Str1,
+ IN CHAR16 *Str2
+ );
+
+/**
+ Retrieves the filename of the directory entry and converts it to UTF-16/UCS-2
+
+ @param[in] Entry Pointer to a EXT4_DIR_ENTRY.
+ @param[out] Ucs2FileName Pointer to an array of CHAR16's, of size EXT4_NAME_MAX + 1.
+
+ @retval EFI_SUCCESS Unicode collation was successfully initialised.
+ @retval !EFI_SUCCESS Failure.
+**/
+EFI_STATUS
+Ext4GetUcs2DirentName (
+ IN EXT4_DIR_ENTRY *Entry,
+ OUT CHAR16 Ucs2FileName[EXT4_NAME_MAX + 1]
+ );
+
+/**
+ Retrieves information about the file and stores it in the EFI_FILE_INFO format.
+
+ @param[in] File Pointer to an opened file.
+ @param[out] Info Pointer to a EFI_FILE_INFO.
+ @param[in out] BufferSize Pointer to the buffer size
+
+ @return Status of the file information request.
+**/
+EFI_STATUS
+Ext4GetFileInfo (
+ IN EXT4_FILE *File,
+ OUT EFI_FILE_INFO *Info,
+ IN OUT UINTN *BufferSize
+ );
+
+/**
+ Reads a directory entry.
+
+ @param[in] Partition Pointer to the ext4 partition.
+ @param[in] File Pointer to the open directory.
+ @param[out] Buffer Pointer to the output buffer.
+ @param[in] Offset Initial directory position.
+ @param[in out] OutLength Pointer to a UINTN that contains the length of the buffer,
+ and the length of the actual EFI_FILE_INFO after the call.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4ReadDir (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ OUT VOID *Buffer,
+ IN UINT64 Offset,
+ IN OUT UINTN *OutLength
+ );
+
+/**
+ Initialises the (empty) extents map, that will work as a cache of extents.
+
+ @param[in] File Pointer to the open file.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4InitExtentsMap (
+ IN EXT4_FILE *File
+ );
+
+/**
+ Frees the extents map, deleting every extent stored.
+
+ @param[in] File Pointer to the open file.
+**/
+VOID
+Ext4FreeExtentsMap (
+ IN EXT4_FILE *File
+ );
+
+/**
+ Calculates the CRC32c checksum of the given buffer.
+
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The CRC32c checksum.
+**/
+UINT32
+CalculateCrc32c (
+ IN CONST VOID *Buffer,
+ IN UINTN Length,
+ IN UINT32 InitialValue
+ );
+
+/**
+ Calculates the CRC16 checksum of the given buffer.
+
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The CRC16 checksum.
+**/
+UINT16
+CalculateCrc16 (
+ IN CONST VOID *Buffer,
+ IN UINTN Length,
+ IN UINT16 InitialValue
+ );
+
+/**
+ Calculates the checksum of the given buffer.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST VOID *Buffer,
+ IN UINTN Length,
+ IN UINT32 InitialValue
+ );
+
+/**
+ Calculates the checksum of the given inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Inode Pointer to the inode.
+ @param[in] InodeNum Inode number.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateInodeChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_INODE *Inode,
+ IN EXT4_INO_NR InodeNum
+ );
+
+/**
+ Checks if the checksum of the inode is correct.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Inode Pointer to the inode.
+ @param[in] InodeNum Inode number.
+
+ @return TRUE if checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4CheckInodeChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_INODE *Inode,
+ IN EXT4_INO_NR InodeNum
+ );
+
+/**
+ Unmounts and frees an ext4 partition.
+
+ @param[in] Partition Pointer to the opened partition.
+
+ @return Status of the unmount.
+**/
+EFI_STATUS
+Ext4UnmountAndFreePartition (
+ IN EXT4_PARTITION *Partition
+ );
+
+/**
+ Checks if the checksum of the block group descriptor is correct.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return TRUE if checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4VerifyBlockGroupDescChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ );
+
+/**
+ Calculates the checksum of the block group descriptor.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] BlockGroupDesc Pointer to the block group descriptor.
+ @param[in] BlockGroupNum Number of the block group.
+
+ @return The checksum.
+**/
+UINT16
+Ext4CalculateBlockGroupDescChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_BLOCK_GROUP_DESC *BlockGroupDesc,
+ IN UINT32 BlockGroupNum
+ );
+
+/**
+ Verifies the existance of a particular RO compat feature set.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] RoCompatFeatureSet Feature set to test.
+
+ @return TRUE if all features are supported, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4HasRoCompat (
+ IN CONST EXT4_PARTITION *Partition,
+ IN UINT32 RoCompatFeatureSet
+ )
+{
+ return (Partition->FeaturesRoCompat & RoCompatFeatureSet) == RoCompatFeatureSet;
+}
+
+/**
+ Verifies the existance of a particular compat feature set.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] RoCompatFeatureSet Feature set to test.
+
+ @return TRUE if all features are supported, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4HasCompat (
+ IN CONST EXT4_PARTITION *Partition,
+ IN UINT32 CompatFeatureSet
+ )
+{
+ return (Partition->FeaturesCompat & CompatFeatureSet) == CompatFeatureSet;
+}
+
+/**
+ Verifies the existance of a particular compat feature set.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] IncompatFeatureSet Feature set to test.
+
+ @return TRUE if all features are supported, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4HasIncompat (
+ IN CONST EXT4_PARTITION *Partition,
+ IN UINT32 IncompatFeatureSet
+ )
+{
+ return (Partition->FeaturesIncompat & IncompatFeatureSet) == IncompatFeatureSet;
+}
+
+// Note: Might be a good idea to provide generic Ext4Has$feature() through macros.
+
+/**
+ Checks if metadata_csum is enabled on the partition.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+
+ @return TRUE if the metadata_csum is supported, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4HasMetadataCsum (
+ IN CONST EXT4_PARTITION *Partition
+ )
+{
+ return Ext4HasRoCompat (Partition, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+}
+
+/**
+ Checks if gdt_csum is enabled on the partition.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+
+ @return TRUE if the gdt_csum is supported, else FALSE.
+**/
+STATIC inline
+BOOLEAN
+Ext4HasGdtCsum (
+ IN CONST EXT4_PARTITION *Partition
+ )
+{
+ return Ext4HasRoCompat (Partition, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM);
+}
+
+#endif
diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
new file mode 100644
index 0000000000..6533de6247
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
@@ -0,0 +1,149 @@
+## @file
+# Ext4 Package
+#
+# UEFI Driver that produces the Simple File System Protocol for a partition that is formatted
+# with the EXT4 file system.
+# More details are available at: https://www.kernel.org/doc/html/v5.4/filesystems/ext4/index.html
+#
+# Copyright (c) 2021 Pedro Falcato
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+# Layout of an EXT2/3/4 filesystem:
+# (note: this driver has been developed using
+# https://www.kernel.org/doc/html/latest/filesystems/ext4/index.html as
+# documentation).
+#
+# An ext2/3/4 filesystem (here on out referred to as simply an ext4 filesystem,
+# due to the similarities) is composed of various concepts:
+#
+# 1) Superblock
+# The superblock is the structure near (1024 bytes offset from the start)
+# the start of the partition, and describes the filesystem in general.
+# Here, we get to know the size of the filesystem's blocks, which features
+# it supports or not, whether it's been cleanly unmounted, how many blocks
+# we have, etc.
+#
+# 2) Block groups
+# EXT4 filesystems are divided into block groups, and each block group covers
+# s_blocks_per_group(8 * Block Size) blocks. Each block group has an
+# associated block group descriptor; these are present directly after the
+# superblock. Each block group descriptor contains the location of the
+# inode table, and the inode and block bitmaps (note these bitmaps are only
+# a block long, which gets us the 8 * Block Size formula covered previously).
+#
+# 3) Blocks
+# The ext4 filesystem is divided in blocks, of size s_log_block_size ^ 1024.
+# Blocks can be allocated using individual block groups's bitmaps. Note
+# that block 0 is invalid and its presence on extents/block tables means
+# it's part of a file hole, and that particular location must be read as
+# a block full of zeros.
+#
+# 4) Inodes
+# The ext4 filesystem divides files/directories into inodes (originally
+# index nodes). Each file/socket/symlink/directory/etc (here on out referred
+# to as a file, since there is no distinction under the ext4 filesystem) is
+# stored as a /nameless/ inode, that is stored in some block group's inode
+# table. Each inode has s_inode_size size (or GOOD_OLD_INODE_SIZE if it's
+# an old filesystem), and holds various metadata about the file. Since the
+# largest inode structure right now is ~160 bytes, the rest of the inode
+# contains inline extended attributes. Inodes' data is stored using either
+# data blocks (under ext2/3) or extents (under ext4).
+#
+# 5) Extents
+# Ext4 inodes store data in extents. These let N contiguous logical blocks
+# that are represented by N contiguous physical blocks be represented by a
+# single extent structure, which minimizes filesystem metadata bloat and
+# speeds up block mapping (particularly due to the fact that high-quality
+# ext4 implementations like linux's try /really/ hard to make the file
+# contiguous, so it's common to have files with almost 0 fragmentation).
+# Inodes that use extents store them in a tree, and the top of the tree
+# is stored on i_data. The tree's leaves always start with an
+# EXT4_EXTENT_HEADER and contain EXT4_EXTENT_INDEX on eh_depth != 0 and
+# EXT4_EXTENT on eh_depth = 0; these entries are always sorted by logical
+# block.
+#
+# 6) Directories
+# Ext4 directories are files that store name -> inode mappings for the
+# logical directory; this is where files get their names, which means ext4
+# inodes do not themselves have names, since they can be linked (present)
+# multiple times with different names. Directories can store entries in two
+# different ways:
+# 1) Classical linear directories: They store entries as a mostly-linked
+# mostly-list of EXT4_DIR_ENTRY.
+# 2) Hash tree directories: These are used for larger directories, with
+# hundreds of entries, and are designed in a backwards compatible way.
+# These are not yet implemented in the Ext4Dxe driver.
+#
+# 7) Journal
+# Ext3/4 filesystems have a journal to help protect the filesystem against
+# system crashes. This is not yet implemented in Ext4Dxe but is described
+# in detail in the Linux kernel's documentation.
+##
+
+
+[Defines]
+ INF_VERSION = 0x00010005
+ BASE_NAME = Ext4Dxe
+ MODULE_UNI_FILE = Ext4Dxe.uni
+ FILE_GUID = 75F2B676-D73B-45CB-B7C1-303C7F4E6FD6
+ MODULE_TYPE = UEFI_DRIVER
+ VERSION_STRING = 1.0
+
+ ENTRY_POINT = Ext4EntryPoint
+ UNLOAD_IMAGE = Ext4Unload
+
+#
+# The following information is for reference only and not required by the build tools.
+#
+# VALID_ARCHITECTURES = IA32 X64 EBC
+#
+
+[Sources]
+ Ext4Dxe.c
+ Partition.c
+ DiskUtil.c
+ Superblock.c
+ BlockGroup.c
+ Inode.c
+ Directory.c
+ Extents.c
+ File.c
+ Collation.c
+ Crc32c.c
+ Crc16.c
+ Ext4Disk.h
+ Ext4Dxe.h
+
+[Packages]
+ MdePkg/MdePkg.dec
+ RedfishPkg/RedfishPkg.dec
+
+[LibraryClasses]
+ UefiRuntimeServicesTableLib
+ UefiBootServicesTableLib
+ MemoryAllocationLib
+ BaseMemoryLib
+ BaseLib
+ UefiLib
+ UefiDriverEntryPoint
+ DebugLib
+ PcdLib
+ OrderedCollectionLib
+ BaseUcs2Utf8Lib
+
+[Guids]
+ gEfiFileInfoGuid ## SOMETIMES_CONSUMES ## UNDEFINED
+ gEfiFileSystemInfoGuid ## SOMETIMES_CONSUMES ## UNDEFINED
+ gEfiFileSystemVolumeLabelInfoIdGuid ## SOMETIMES_CONSUMES ## UNDEFINED
+
+[Protocols]
+ gEfiDiskIoProtocolGuid ## TO_START
+ gEfiDiskIo2ProtocolGuid ## TO_START
+ gEfiBlockIoProtocolGuid ## TO_START
+ gEfiSimpleFileSystemProtocolGuid ## BY_START
+ gEfiUnicodeCollationProtocolGuid ## TO_START
+ gEfiUnicodeCollation2ProtocolGuid ## TO_START
+
+[Pcd]
+ gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultLang ## SOMETIMES_CONSUMES
+ gEfiMdePkgTokenSpaceGuid.PcdUefiVariableDefaultPlatformLang ## SOMETIMES_CONSUMES
diff --git a/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni
new file mode 100644
index 0000000000..7476fbf9bd
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni
@@ -0,0 +1,15 @@
+## @file
+# Ext4 Package
+#
+# UEFI Driver that produces the Simple File System Protocol for a partition that is formatted
+# with the EXT4 file system.
+# More details are available at: https://www.kernel.org/doc/html/v5.4/filesystems/ext4/index.html
+#
+# Copyright (c) 2021 Pedro Falcato
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+#string STR_MODULE_ABSTRACT #language en-US "UEFI driver for the EXT4 file system."
+
+#string STR_MODULE_DESCRIPTION #language en-US "Produces the EFI Simple File System protocol."
diff --git a/Features/Ext4Pkg/Ext4Dxe/Extents.c b/Features/Ext4Pkg/Ext4Dxe/Extents.c
new file mode 100644
index 0000000000..86ad0a8701
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Extents.c
@@ -0,0 +1,618 @@
+/** @file Extent related routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+/**
+ Checks if the checksum of the extent data block is correct.
+ @param[in] ExtHeader Pointer to the EXT4_EXTENT_HEADER.
+ @param[in] File Pointer to the file.
+
+ @return TRUE if the checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4CheckExtentChecksum (
+ IN CONST EXT4_EXTENT_HEADER *ExtHeader,
+ IN CONST EXT4_FILE *File
+ );
+
+/**
+ Calculates the checksum of the extent data block.
+ @param[in] ExtHeader Pointer to the EXT4_EXTENT_HEADER.
+ @param[in] File Pointer to the file.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateExtentChecksum (
+ IN CONST EXT4_EXTENT_HEADER *ExtHeader,
+ IN CONST EXT4_FILE *File
+ );
+
+/**
+ Caches a range of extents, by allocating pool memory for each extent and adding it to the tree.
+
+ @param[in] File Pointer to the open file.
+ @param[in] Extents Pointer to an array of extents.
+ @param[in] NumberExtents Length of the array.
+**/
+VOID
+Ext4CacheExtents (
+ IN EXT4_FILE *File,
+ IN CONST EXT4_EXTENT *Extents,
+ IN UINT16 NumberExtents
+ );
+
+/**
+ Gets an extent from the extents cache of the file.
+
+ @param[in] File Pointer to the open file.
+ @param[in] Block Block we want to grab.
+
+ @return Pointer to the extent, or NULL if it was not found.
+**/
+EXT4_EXTENT *
+Ext4GetExtentFromMap (
+ IN EXT4_FILE *File,
+ IN UINT32 Block
+ );
+
+/**
+ Retrieves the pointer to the top of the extent tree.
+ @param[in] Inode Pointer to the inode structure.
+
+ @return Pointer to an EXT4_EXTENT_HEADER. This pointer is inside
+ the inode and must not be freed.
+**/
+STATIC
+EXT4_EXTENT_HEADER *
+Ext4GetInoExtentHeader (
+ IN EXT4_INODE *Inode
+ )
+{
+ return (EXT4_EXTENT_HEADER *)Inode->i_data;
+}
+
+/**
+ Checks if an extent header is valid.
+ @param[in] Header Pointer to the EXT4_EXTENT_HEADER structure.
+
+ @return TRUE if valid, FALSE if not.
+**/
+STATIC
+BOOLEAN
+Ext4ExtentHeaderValid (
+ IN CONST EXT4_EXTENT_HEADER *Header
+ )
+{
+ if(Header->eh_depth > EXT4_EXTENT_TREE_MAX_DEPTH) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Invalid extent header depth %u\n", Header->eh_depth));
+ return FALSE;
+ }
+
+ if(Header->eh_magic != EXT4_EXTENT_HEADER_MAGIC) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Invalid extent header magic %x\n", Header->eh_magic));
+ return FALSE;
+ }
+
+ if(Header->eh_max < Header->eh_entries) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "[ext4] Invalid extent header num entries %u max entries %u\n",
+ Header->eh_entries,
+ Header->eh_max
+ ));
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Performs a binary search for a EXT4_EXTENT_INDEX that corresponds to a
+ logical block in a given extent tree node.
+
+ @param[in] Header Pointer to the EXT4_EXTENT_HEADER structure.
+ @param[in] LogicalBlock Block that will be searched
+
+ @return Pointer to the found EXT4_EXTENT_INDEX.
+**/
+STATIC
+EXT4_EXTENT_INDEX *
+Ext4BinsearchExtentIndex (
+ IN EXT4_EXTENT_HEADER *Header,
+ IN EXT4_BLOCK_NR LogicalBlock
+ )
+{
+ EXT4_EXTENT_INDEX *l;
+ EXT4_EXTENT_INDEX *r;
+ EXT4_EXTENT_INDEX *m;
+
+ l = ((EXT4_EXTENT_INDEX *)(Header + 1)) + 1;
+ r = ((EXT4_EXTENT_INDEX *)(Header + 1)) + Header->eh_entries - 1;
+
+ // Perform a mostly-standard binary search on the array
+ // This works very nicely because the extents arrays are always sorted.
+
+ while(l <= r) {
+ m = l + (r - l) / 2;
+
+ if(LogicalBlock < m->ei_block) {
+ r = m - 1;
+ } else {
+ l = m + 1;
+ }
+ }
+
+ return l - 1;
+}
+
+/**
+ Performs a binary search for a EXT4_EXTENT that corresponds to a
+ logical block in a given extent tree node.
+
+ @param[in] Header Pointer to the EXT4_EXTENT_HEADER structure.
+ @param[in] LogicalBlock Block that will be searched
+
+ @return Pointer to the found EXT4_EXTENT_INDEX, else NULL if the array is empty.
+ Note: The caller must check if the logical block
+ is actually mapped under the given extent.
+**/
+STATIC
+EXT4_EXTENT *
+Ext4BinsearchExtentExt (
+ IN EXT4_EXTENT_HEADER *Header,
+ IN EXT4_BLOCK_NR LogicalBlock
+ )
+{
+ EXT4_EXTENT *l;
+ EXT4_EXTENT *r;
+ EXT4_EXTENT *m;
+
+ l = ((EXT4_EXTENT *)(Header + 1)) + 1;
+ r = ((EXT4_EXTENT *)(Header + 1)) + Header->eh_entries - 1;
+ // Perform a mostly-standard binary search on the array
+ // This works very nicely because the extents arrays are always sorted.
+
+ // Empty array
+ if(Header->eh_entries == 0) {
+ return NULL;
+ }
+
+ while(l <= r) {
+ m = l + (r - l) / 2;
+
+ if(LogicalBlock < m->ee_block) {
+ r = m - 1;
+ } else {
+ l = m + 1;
+ }
+ }
+
+ return l - 1;
+}
+
+/**
+ Retrieves the leaf block from an EXT4_EXTENT_INDEX.
+
+ @param[in] Index Pointer to the EXT4_EXTENT_INDEX structure.
+
+ @return Block number of the leaf node.
+**/
+STATIC
+EXT4_BLOCK_NR
+Ext4ExtentIdxLeafBlock (
+ IN EXT4_EXTENT_INDEX *Index
+ )
+{
+ return LShiftU64 (Index->ei_leaf_hi, 32) | Index->ei_leaf_lo;
+}
+
+STATIC UINTN GetExtentRequests = 0;
+STATIC UINTN GetExtentCacheHits = 0;
+
+/**
+ Retrieves an extent from an EXT4 inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] File Pointer to the opened file.
+ @param[in] LogicalBlock Block number which the returned extent must cover.
+ @param[out] Extent Pointer to the output buffer, where the extent will be copied to.
+
+ @retval EFI_SUCCESS Retrieval was succesful.
+ @retval EFI_NO_MAPPING Block has no mapping.
+**/
+EFI_STATUS
+Ext4GetExtent (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ IN EXT4_BLOCK_NR LogicalBlock,
+ OUT EXT4_EXTENT *Extent
+ )
+{
+ EXT4_INODE *Inode;
+ VOID *Buffer;
+ EXT4_EXTENT *Ext;
+ UINT32 CurrentDepth;
+ EXT4_EXTENT_HEADER *ExtHeader;
+
+ Inode = File->Inode;
+ Ext = NULL;
+ Buffer = NULL;
+
+ DEBUG ((DEBUG_INFO, "[ext4] Looking up extent for block %lu\n", LogicalBlock));
+
+ if (!(Inode->i_flags & EXT4_EXTENTS_FL)) {
+ return EFI_UNSUPPORTED;
+ }
+
+ // ext4 does not have support for logical block numbers bigger than UINT32_MAX
+ if (LogicalBlock > (UINT32)- 1) {
+ return EFI_NO_MAPPING;
+ }
+
+ GetExtentRequests++;
+ #if DEBUG_EXTENT_CACHE
+ DEBUG ((
+ DEBUG_INFO,
+ "[ext4] Requests %lu, hits %lu, misses %lu\n",
+ GetExtentRequests,
+ GetExtentCacheHits,
+ GetExtentRequests - GetExtentCacheHits
+ ));
+ #endif
+
+ // Note: Right now, holes are the single biggest reason for cache misses
+ // We should find a way to get (or cache) holes
+ if ((Ext = Ext4GetExtentFromMap (File, (UINT32)LogicalBlock)) != NULL) {
+ *Extent = *Ext;
+ GetExtentCacheHits++;
+
+ return EFI_SUCCESS;
+ }
+
+ // Slow path, we'll need to read from disk and (try to) cache those extents.
+
+ ExtHeader = Ext4GetInoExtentHeader (Inode);
+
+ if(!Ext4ExtentHeaderValid (ExtHeader)) {
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ CurrentDepth = ExtHeader->eh_depth;
+
+ while(ExtHeader->eh_depth != 0) {
+ EXT4_EXTENT_INDEX *Index;
+ EFI_STATUS Status;
+
+ CurrentDepth--;
+ // While depth != 0, we're traversing the tree itself and not any leaves
+ // As such, every entry is an EXT4_EXTENT_INDEX entry
+ // Note: Entries after the extent header, either index or actual extent, are always sorted.
+ // Therefore, we can use binary search, and it's actually the standard for doing so
+ // (see FreeBSD).
+
+ Index = Ext4BinsearchExtentIndex (ExtHeader, LogicalBlock);
+
+ if(Buffer == NULL) {
+ Buffer = AllocatePool (Partition->BlockSize);
+ if(Buffer == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+ }
+
+ // Read the leaf block onto the previously-allocated buffer.
+
+ Status = Ext4ReadBlocks (Partition, Buffer, 1, Ext4ExtentIdxLeafBlock (Index));
+ if(EFI_ERROR (Status)) {
+ FreePool (Buffer);
+ return Status;
+ }
+
+ ExtHeader = Buffer;
+
+ if(!Ext4ExtentHeaderValid (ExtHeader)) {
+ FreePool (Buffer);
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ if(!Ext4CheckExtentChecksum (ExtHeader, File)) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Invalid extent checksum\n"));
+ FreePool (Buffer);
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ if(ExtHeader->eh_depth != CurrentDepth) {
+ FreePool (Buffer);
+ return EFI_VOLUME_CORRUPTED;
+ }
+ }
+
+ /* We try to cache every extent under a single leaf, since it's quite likely that we
+ * may need to access things sequentially. Furthermore, ext4 block allocation as done
+ * by linux (and possibly other systems) is quite fancy and usually it results in a small number of extents.
+ * Therefore, we shouldn't have any memory issues.
+ **/
+ Ext4CacheExtents (File, (EXT4_EXTENT *)(ExtHeader + 1), ExtHeader->eh_entries);
+
+ Ext = Ext4BinsearchExtentExt (ExtHeader, LogicalBlock);
+
+ if(!Ext) {
+ if(Buffer != NULL) {
+ FreePool (Buffer);
+ }
+
+ return EFI_NO_MAPPING;
+ }
+
+ if(!(LogicalBlock >= Ext->ee_block && Ext->ee_block + Ext->ee_len > LogicalBlock)) {
+ // This extent does not cover the block
+ if(Buffer != NULL) {
+ FreePool (Buffer);
+ }
+
+ return EFI_NO_MAPPING;
+ }
+
+ *Extent = *Ext;
+
+ if(Buffer != NULL) {
+ FreePool (Buffer);
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Compare two EXT4_EXTENT structs.
+ Used in the extent map's ORDERED_COLLECTION.
+
+ @param[in] UserStruct1 Pointer to the first user structure.
+
+ @param[in] UserStruct2 Pointer to the second user structure.
+
+ @retval <0 If UserStruct1 compares less than UserStruct2.
+
+ @retval 0 If UserStruct1 compares equal to UserStruct2.
+
+ @retval >0 If UserStruct1 compares greater than UserStruct2.
+**/
+STATIC
+INTN EFIAPI
+Ext4ExtentsMapStructCompare (
+ IN CONST VOID *UserStruct1,
+ IN CONST VOID *UserStruct2
+ )
+{
+ CONST EXT4_EXTENT *Extent1 = UserStruct1;
+ CONST EXT4_EXTENT *Extent2 = UserStruct2;
+
+ // TODO: Detect extent overlaps? in case of corruption.
+
+ /* DEBUG((DEBUG_INFO, "[ext4] extent 1 %u extent 2 %u = %ld\n", Extent1->ee_block,
+ Extent2->ee_block, Extent1->ee_block - Extent2->ee_block)); */
+ return Extent1->ee_block < Extent2->ee_block ? - 1 :
+ Extent1->ee_block > Extent2->ee_block ? 1 : 0;
+}
+
+/**
+ Compare a standalone key against a EXT4_EXTENT containing an embedded key.
+ Used in the extent map's ORDERED_COLLECTION.
+
+ @param[in] StandaloneKey Pointer to the bare key.
+
+ @param[in] UserStruct Pointer to the user structure with the embedded
+ key.
+
+ @retval <0 If StandaloneKey compares less than UserStruct's key.
+
+ @retval 0 If StandaloneKey compares equal to UserStruct's key.
+
+ @retval >0 If StandaloneKey compares greater than UserStruct's key.
+**/
+STATIC
+INTN EFIAPI
+Ext4ExtentsMapKeyCompare (
+ IN CONST VOID *StandaloneKey,
+ IN CONST VOID *UserStruct
+ )
+{
+ CONST EXT4_EXTENT *Extent;
+ UINT32 Block;
+
+ // Note that logical blocks are 32-bits in size so no truncation can happen here
+ // with regards to 32-bit architectures.
+ Extent = UserStruct;
+ Block = (UINT32)(UINTN)StandaloneKey;
+
+ // DEBUG((DEBUG_INFO, "[ext4] comparing %u %u\n", Block, Extent->ee_block));
+ if(Block >= Extent->ee_block && Block < Extent->ee_block + Extent->ee_len) {
+ return 0;
+ }
+
+ return Block < Extent->ee_block ? - 1 :
+ Block > Extent->ee_block ? 1 : 0;
+}
+
+/**
+ Initialises the (empty) extents map, that will work as a cache of extents.
+
+ @param[in] File Pointer to the open file.
+
+ @return Result of the operation.
+**/
+EFI_STATUS
+Ext4InitExtentsMap (
+ IN EXT4_FILE *File
+ )
+{
+ File->ExtentsMap = OrderedCollectionInit (Ext4ExtentsMapStructCompare, Ext4ExtentsMapKeyCompare);
+ if (!File->ExtentsMap) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Frees the extents map, deleting every extent stored.
+
+ @param[in] File Pointer to the open file.
+**/
+VOID
+Ext4FreeExtentsMap (
+ IN EXT4_FILE *File
+ )
+{
+ // Keep calling Min(), so we get an arbitrary node we can delete.
+ // If Min() returns NULL, it's empty.
+
+ ORDERED_COLLECTION_ENTRY *MinEntry;
+ EXT4_EXTENT *Ext;
+
+ MinEntry = NULL;
+
+ while ((MinEntry = OrderedCollectionMin (File->ExtentsMap)) != NULL) {
+ OrderedCollectionDelete (File->ExtentsMap, MinEntry, (VOID **)&Ext);
+ FreePool (Ext);
+ }
+
+ ASSERT (OrderedCollectionIsEmpty (File->ExtentsMap));
+
+ OrderedCollectionUninit (File->ExtentsMap);
+ File->ExtentsMap = NULL;
+}
+
+/**
+ Caches a range of extents, by allocating pool memory for each extent and adding it to the tree.
+
+ @param[in] File Pointer to the open file.
+ @param[in] Extents Pointer to an array of extents.
+ @param[in] NumberExtents Length of the array.
+**/
+VOID
+Ext4CacheExtents (
+ IN EXT4_FILE *File, IN CONST EXT4_EXTENT *Extents, IN UINT16 NumberExtents
+ )
+{
+ UINT16 i;
+
+ /* Note that any out of memory condition might mean we don't get to cache a whole leaf of extents
+ * in which case, future insertions might fail.
+ */
+
+ for(i = 0; i < NumberExtents; i++, Extents++) {
+ EXT4_EXTENT *Extent;
+ EFI_STATUS Status;
+
+ Extent = AllocatePool (sizeof (EXT4_EXTENT));
+
+ if (Extent == NULL) {
+ return;
+ }
+
+ CopyMem (Extent, Extents, sizeof (EXT4_EXTENT));
+ Status = OrderedCollectionInsert (File->ExtentsMap, NULL, Extent);
+
+ // EFI_ALREADY_STARTED = already exists in the tree.
+ if (EFI_ERROR (Status)) {
+ FreePool (Extent);
+
+ if(Status == EFI_ALREADY_STARTED) {
+ continue;
+ }
+
+ return;
+ }
+
+ #if DEBUG_EXTENT_CACHE
+ DEBUG ((
+ DEBUG_INFO,
+ "[ext4] Cached extent [%lu, %lu]\n",
+ Extent->ee_block,
+ Extent->ee_block + Extent->ee_len - 1
+ ));
+ #endif
+ }
+}
+
+/**
+ Gets an extent from the extents cache of the file.
+
+ @param[in] File Pointer to the open file.
+ @param[in] Block Block we want to grab.
+
+ @return Pointer to the extent, or NULL if it was not found.
+**/
+EXT4_EXTENT *
+Ext4GetExtentFromMap (
+ IN EXT4_FILE *File,
+ IN UINT32 Block
+ )
+{
+ ORDERED_COLLECTION_ENTRY *Entry;
+
+ Entry = OrderedCollectionFind (File->ExtentsMap, (CONST VOID *)(UINTN)Block);
+
+ if (Entry == NULL) {
+ return NULL;
+ }
+
+ return OrderedCollectionUserStruct (Entry);
+}
+
+/**
+ Calculates the checksum of the extent data block.
+ @param[in] ExtHeader Pointer to the EXT4_EXTENT_HEADER.
+ @param[in] File Pointer to the file.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateExtentChecksum (
+ IN CONST EXT4_EXTENT_HEADER *ExtHeader,
+ IN CONST EXT4_FILE *File
+ )
+{
+ UINT32 Csum;
+ EXT4_PARTITION *Partition;
+ EXT4_INODE *Inode;
+
+ Partition = File->Partition;
+ Inode = File->Inode;
+
+ Csum = Ext4CalculateChecksum (Partition, &File->InodeNum, sizeof (EXT4_INO_NR), Partition->InitialSeed);
+ Csum = Ext4CalculateChecksum (Partition, &Inode->i_generation, sizeof (Inode->i_generation), Csum);
+ Csum = Ext4CalculateChecksum (Partition, ExtHeader, Partition->BlockSize - sizeof (EXT4_EXTENT_TAIL), Csum);
+
+ return Csum;
+}
+
+/**
+ Checks if the checksum of the extent data block is correct.
+ @param[in] ExtHeader Pointer to the EXT4_EXTENT_HEADER.
+ @param[in] File Pointer to the file.
+
+ @return TRUE if the checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4CheckExtentChecksum (
+ IN CONST EXT4_EXTENT_HEADER *ExtHeader,
+ IN CONST EXT4_FILE *File
+ )
+{
+ EXT4_PARTITION *Partition;
+ EXT4_EXTENT_TAIL *Tail;
+
+ Partition = File->Partition;
+
+ if(!Ext4HasMetadataCsum (Partition)) {
+ return TRUE;
+ }
+
+ Tail = (EXT4_EXTENT_TAIL *)((CONST CHAR8 *)ExtHeader + (Partition->BlockSize - 4));
+
+ return Tail->eb_checksum == Ext4CalculateExtentChecksum (ExtHeader, File);
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/File.c b/Features/Ext4Pkg/Ext4Dxe/File.c
new file mode 100644
index 0000000000..4db0d2fe59
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/File.c
@@ -0,0 +1,786 @@
+/** @file EFI_FILE_PROTOCOL implementation for EXT4
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+#include <Library/BaseUcs2Utf8Lib.h>
+
+/**
+ Duplicates a file structure.
+
+ @param[in] Original Pointer to the original file.
+
+ @return Pointer to the new file structure.
+**/
+STATIC
+EXT4_FILE *
+Ext4DuplicateFile (
+ IN CONST EXT4_FILE *Original
+ );
+
+/**
+ Gets the next path segment.
+
+ @param[in] Path Pointer to the rest of the path.
+ @param[out] PathSegment Pointer to the buffer that will hold the path segment.
+ Note: It's necessarily EXT4_NAME_MAX +1 long.
+ @param[out] Length Pointer to the UINTN that will hold the length of the path segment.
+
+ @retval !EFI_SUCCESS The path segment is too large(> EXT4_NAME_MAX).
+**/
+STATIC
+EFI_STATUS
+GetPathSegment (
+ IN CONST CHAR16 *Path, OUT CHAR16 *PathSegment, OUT UINTN *Length
+ )
+{
+ CONST CHAR16 *Start = Path;
+ CONST CHAR16 *End = Path;
+
+ // The path segment ends on a backslash or a null terminator
+ for( ; *End != L'\0' && *End != L'\\'; End++) {
+ }
+
+ *Length = End - Start;
+
+ return StrnCpyS (PathSegment, EXT4_NAME_MAX, Start, End - Start);
+}
+
+/**
+ Detects if we have more path segments on the path.
+
+ @param[in] Path Pointer to the rest of the path.
+ @return True if we're on the last segment, false if there are more
+ segments.
+**/
+STATIC
+BOOLEAN
+Ext4IsLastPathSegment (
+ IN CONST CHAR16 *Path
+ )
+{
+ while(Path[0] == L'\\') {
+ Path++;
+ }
+
+ return Path[0] == '\0';
+}
+
+#define EXT4_INO_PERM_READ_OWNER 0400
+#define EXT4_INO_PERM_WRITE_OWNER 0200
+#define EXT4_INO_PERM_EXEC_OWNER 0100
+
+/**
+ Detects if we have permissions to open the file on the desired mode.
+
+ @param[in out] File Pointer to the file we're opening.
+ @param[in] OpenMode Mode in which to open the file.
+
+ @return True if the open was succesful, false if we don't have
+ enough permissions.
+**/
+STATIC
+BOOLEAN
+Ext4ApplyPermissions (
+ IN OUT EXT4_FILE *File, IN UINT64 OpenMode
+ )
+{
+ UINT16 NeededPerms;
+
+ NeededPerms = 0;
+
+ if((OpenMode & EFI_FILE_MODE_READ) != 0) {
+ NeededPerms |= EXT4_INO_PERM_READ_OWNER;
+ }
+
+ if((OpenMode & EFI_FILE_MODE_WRITE) != 0) {
+ NeededPerms |= EXT4_INO_PERM_WRITE_OWNER;
+ }
+
+ if((File->Inode->i_mode & NeededPerms) != NeededPerms) {
+ return FALSE;
+ }
+
+ File->OpenMode = OpenMode;
+
+ return TRUE;
+}
+
+/**
+ Detects if we have permissions to search on the directory.
+
+ @param[in out] File Pointer to the open directory.
+
+ @return True if we have permission to search, else false.
+**/
+STATIC
+BOOLEAN
+Ext4DirCanLookup (
+ IN CONST EXT4_FILE *File
+ )
+{
+ // In UNIX, executable permission on directories means that we have permission to look up
+ // files in a directory.
+ return (File->Inode->i_mode & EXT4_INO_PERM_EXEC_OWNER) == EXT4_INO_PERM_EXEC_OWNER;
+}
+
+/**
+ Opens a new file relative to the source file's location.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to the source location. This would typically be an open
+ handle to a directory.
+ @param NewHandle A pointer to the location to return the opened handle for the new
+ file.
+ @param FileName The Null-terminated string of the name of the file to be opened.
+ The file name may contain the following path modifiers: "\", ".",
+ and "..".
+ @param OpenMode The mode to open the file. The only valid combinations that the
+ file may be opened with are: Read, Read/Write, or Create/Read/Write.
+ @param Attributes Only valid for EFI_FILE_MODE_CREATE, in which case these are the
+ attribute bits for the newly created file.
+
+ @retval EFI_SUCCESS The file was opened.
+ @retval EFI_NOT_FOUND The specified file could not be found on the device.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_MEDIA_CHANGED The device has a different medium in it or the medium is no
+ longer supported.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED An attempt was made to create a file, or open a file for write
+ when the media is write-protected.
+ @retval EFI_ACCESS_DENIED The service denied access to the file.
+ @retval EFI_OUT_OF_RESOURCES Not enough resources were available to open the file.
+ @retval EFI_VOLUME_FULL The volume is full.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4Open (
+ IN EFI_FILE_PROTOCOL *This,
+ OUT EFI_FILE_PROTOCOL **NewHandle,
+ IN CHAR16 *FileName,
+ IN UINT64 OpenMode,
+ IN UINT64 Attributes
+ )
+{
+ EXT4_FILE *Current;
+ EXT4_PARTITION *Partition;
+ UINTN Level;
+
+ Current = (EXT4_FILE *)This;
+ Partition = Current->Partition;
+ Level = 0;
+
+ DEBUG ((DEBUG_INFO, "[ext4] Ext4Open %s\n", FileName));
+ // If the path starts with a backslash, we treat the root directory as the base directory
+ if(FileName[0] == L'\\') {
+ FileName++;
+ Current = Partition->Root;
+ }
+
+ while(FileName[0] != L'\0') {
+ CHAR16 PathSegment[EXT4_NAME_MAX + 1];
+ UINTN Length;
+ EXT4_FILE *File;
+ EFI_STATUS Status;
+
+ // Discard leading path separators
+ while(FileName[0] == L'\\') {
+ FileName++;
+ }
+
+ if(GetPathSegment (FileName, PathSegment, &Length) != EFI_SUCCESS) {
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ // Reached the end of the path
+ if(Length == 0) {
+ break;
+ }
+
+ FileName += Length;
+
+ DEBUG ((DEBUG_INFO, "[ext4] Opening %s\n", PathSegment));
+
+ // TODO: What to do with symlinks? They're nonsense when absolute but may
+ // be useful when they're relative.
+
+ if (!Ext4FileIsDir (Current)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ if (!Ext4IsLastPathSegment (FileName)) {
+ if (!Ext4DirCanLookup (Current)) {
+ return EFI_ACCESS_DENIED;
+ }
+ }
+
+ Status = Ext4OpenFile (Current, PathSegment, Partition, EFI_FILE_MODE_READ, &File);
+
+ if(EFI_ERROR (Status) && Status != EFI_NOT_FOUND) {
+ return Status;
+ } else if(Status == EFI_NOT_FOUND) {
+ // WRITE SUPPORT: Handle file creation when write support is added
+ return Status;
+ }
+
+ // Check if this is a valid file to open in EFI
+ if(!Ext4FileIsOpenable (File)) {
+ Ext4CloseInternal (File);
+ // This looks like an /okay/ status to return.
+ return EFI_ACCESS_DENIED;
+ }
+
+ if(Level != 0) {
+ // Careful not to close the base directory
+ Ext4CloseInternal (Current);
+ }
+
+ Level++;
+
+ Current = File;
+ }
+
+ if (Level == 0) {
+ // We opened the base directory again, so we need to duplicate the file structure
+ Current = Ext4DuplicateFile (Current);
+ if (Current == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+ }
+
+ if(!Ext4ApplyPermissions (Current, OpenMode)) {
+ Ext4CloseInternal (Current);
+ return EFI_ACCESS_DENIED;
+ }
+
+ *NewHandle = &Current->Protocol;
+
+ DEBUG ((DEBUG_INFO, "Open successful\n"));
+ DEBUG ((DEBUG_INFO, "Opened filename %s\n", Current->FileName));
+ return EFI_SUCCESS;
+}
+
+/**
+ Closes a specified file handle.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to close.
+
+ @retval EFI_SUCCESS The file was closed.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Close (
+ IN EFI_FILE_PROTOCOL *This
+ )
+{
+ return Ext4CloseInternal ((EXT4_FILE *)This);
+}
+
+/**
+ Closes a file.
+
+ @param[in] File Pointer to the file.
+
+ @return Status of the closing of the file.
+**/
+EFI_STATUS
+Ext4CloseInternal (
+ IN EXT4_FILE *File
+ )
+{
+ if(File == File->Partition->Root && !File->Partition->Unmounting) {
+ return EFI_SUCCESS;
+ }
+
+ DEBUG ((DEBUG_INFO, "[ext4] Closed file %p (inode %lu)\n", File, File->InodeNum));
+ RemoveEntryList (&File->OpenFilesListNode);
+ FreePool (File->FileName);
+ FreePool (File->Inode);
+ Ext4FreeExtentsMap (File);
+ FreePool (File);
+ return EFI_SUCCESS;
+}
+
+/**
+ Close and delete the file handle.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the
+ handle to the file to delete.
+
+ @retval EFI_SUCCESS The file was closed and deleted, and the handle was closed.
+ @retval EFI_WARN_DELETE_FAILURE The handle was closed, but the file was not deleted.
+
+**/
+EFI_STATUS EFIAPI
+Ext4Delete (
+ IN EFI_FILE_PROTOCOL *This
+ )
+{
+ // Write support
+ Ext4Close (This);
+ return EFI_WARN_DELETE_FAILURE;
+}
+
+/**
+ Reads data from a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to read data from.
+ @param BufferSize On input, the size of the Buffer. On output, the amount of data
+ returned in Buffer. In both cases, the size is measured in bytes.
+ @param Buffer The buffer into which the data is read.
+
+ @retval EFI_SUCCESS Data was read.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_DEVICE_ERROR An attempt was made to read from a deleted file.
+ @retval EFI_DEVICE_ERROR On entry, the current file position is beyond the end of the file.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory
+ entry. BufferSize has been updated with the size
+ needed to complete the request.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4ReadFile (
+ IN EFI_FILE_PROTOCOL *This,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ )
+{
+ EXT4_FILE *File;
+ EXT4_PARTITION *Partition;
+ EFI_STATUS Status;
+
+ File = (EXT4_FILE *)This;
+ Partition = File->Partition;
+
+ ASSERT (Ext4FileIsOpenable (File));
+
+ if(Ext4FileIsReg (File)) {
+ Status = Ext4Read (Partition, File, Buffer, File->Position, BufferSize);
+ if(Status == EFI_SUCCESS) {
+ File->Position += *BufferSize;
+ }
+
+ return Status;
+ } else if(Ext4FileIsDir (File)) {
+ Status = Ext4ReadDir (Partition, File, Buffer, File->Position, BufferSize);
+ DEBUG ((DEBUG_INFO, "[ext4] ReadDir status %lx\n", Status));
+
+ if(Status == EFI_SUCCESS) {
+ DEBUG ((DEBUG_INFO, "[ext4] ReadDir retlen %lu\n", *BufferSize));
+ }
+
+ return Status;
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Writes data to a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to write data to.
+ @param BufferSize On input, the size of the Buffer. On output, the amount of data
+ actually written. In both cases, the size is measured in bytes.
+ @param Buffer The buffer of data to write.
+
+ @retval EFI_SUCCESS Data was written.
+ @retval EFI_UNSUPPORTED Writes to open directory files are not supported.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_DEVICE_ERROR An attempt was made to write to a deleted file.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED The file or medium is write-protected.
+ @retval EFI_ACCESS_DENIED The file was opened read only.
+ @retval EFI_VOLUME_FULL The volume is full.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4WriteFile (
+ IN EFI_FILE_PROTOCOL *This,
+ IN OUT UINTN *BufferSize,
+ IN VOID *Buffer
+ )
+{
+ EXT4_FILE *File;
+
+ File = (EXT4_FILE *)This;
+
+ if(!(File->OpenMode & EFI_FILE_MODE_WRITE)) {
+ return EFI_ACCESS_DENIED;
+ }
+
+ // TODO: Add write support
+ return EFI_WRITE_PROTECTED;
+}
+
+/**
+ Returns a file's current position.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle to get the current position on.
+ @param Position The address to return the file's current position value.
+
+ @retval EFI_SUCCESS The position was returned.
+ @retval EFI_UNSUPPORTED The request is not valid on open directories.
+ @retval EFI_DEVICE_ERROR An attempt was made to get the position from a deleted file.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4GetPosition (
+ IN EFI_FILE_PROTOCOL *This,
+ OUT UINT64 *Position
+ )
+{
+ EXT4_FILE *File;
+
+ File = (EXT4_FILE *)This;
+
+ if(Ext4FileIsDir (File)) {
+ return EFI_UNSUPPORTED;
+ }
+
+ *Position = File->Position;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Sets a file's current position.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the
+ file handle to set the requested position on.
+ @param Position The byte position from the start of the file to set.
+
+ @retval EFI_SUCCESS The position was set.
+ @retval EFI_UNSUPPORTED The seek request for nonzero is not valid on open
+ directories.
+ @retval EFI_DEVICE_ERROR An attempt was made to set the position of a deleted file.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4SetPosition (
+ IN EFI_FILE_PROTOCOL *This,
+ IN UINT64 Position
+ )
+{
+ EXT4_FILE *File;
+
+ File = (EXT4_FILE *)This;
+
+ // Only seeks to 0 (so it resets the ReadDir operation) are allowed
+ if(Ext4FileIsDir (File) && Position != 0) {
+ return EFI_UNSUPPORTED;
+ }
+
+ // -1 (0xffffff.......) seeks to the end of the file
+ if(Position == (UINT64)- 1) {
+ Position = EXT4_INODE_SIZE (File->Inode);
+ }
+
+ File->Position = Position;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Retrieves information about the file and stores it in the EFI_FILE_INFO format.
+
+ @param[in] File Pointer to an opened file.
+ @param[out] Info Pointer to a EFI_FILE_INFO.
+ @param[in out] BufferSize Pointer to the buffer size
+
+ @return Status of the file information request.
+**/
+EFI_STATUS
+Ext4GetFileInfo (
+ IN EXT4_FILE *File, OUT EFI_FILE_INFO *Info, IN OUT UINTN *BufferSize
+ )
+{
+ // TODO: Get a way to set the directory entry for SetFileInfo
+ UINTN FileNameLen;
+ UINTN FileNameSize;
+ UINTN NeededLength;
+
+ FileNameLen = StrLen (File->FileName);
+ FileNameSize = StrSize (File->FileName);
+
+ NeededLength = SIZE_OF_EFI_FILE_INFO + FileNameSize;
+
+ if(*BufferSize < NeededLength) {
+ *BufferSize = NeededLength;
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ Info->FileSize = EXT4_INODE_SIZE (File->Inode);
+ Info->PhysicalSize = Ext4FilePhysicalSpace (File);
+ Ext4FileATime (File, &Info->LastAccessTime);
+ Ext4FileMTime (File, &Info->ModificationTime);
+ Ext4FileCreateTime (File, &Info->LastAccessTime);
+ Info->Attribute = 0;
+ Info->Size = NeededLength;
+
+ if(Ext4FileIsDir (File)) {
+ Info->Attribute |= EFI_FILE_DIRECTORY;
+ }
+
+ *BufferSize = NeededLength;
+
+ return StrCpyS (Info->FileName, FileNameLen + 1, File->FileName);
+}
+
+/**
+ Retrieves information about the filesystem and stores it in the EFI_FILE_SYSTEM_INFO format.
+
+ @param[in] Part Pointer to the opened partition.
+ @param[out] Info Pointer to a EFI_FILE_SYSTEM_INFO.
+ @param[in out] BufferSize Pointer to the buffer size
+
+ @return Status of the file information request.
+**/
+STATIC
+EFI_STATUS
+Ext4GetFilesystemInfo (
+ IN EXT4_PARTITION *Part, OUT EFI_FILE_SYSTEM_INFO *Info, IN OUT UINTN *BufferSize
+ )
+{
+ // Length of s_volume_name + null terminator
+ CHAR8 TempVolName[16 + 1];
+ CHAR16 *VolumeName;
+ UINTN VolNameLength;
+ EFI_STATUS Status;
+ UINTN NeededLength;
+ EXT4_BLOCK_NR TotalBlocks;
+ EXT4_BLOCK_NR FreeBlocks;
+
+ VolNameLength = 0;
+ VolumeName = NULL;
+
+ // s_volume_name is only valid on dynamic revision; old filesystems don't support this
+ if(Part->SuperBlock.s_rev_level == EXT4_DYNAMIC_REV) {
+ CopyMem (TempVolName, (CONST CHAR8 *)Part->SuperBlock.s_volume_name, 16);
+ TempVolName[16] = '\0';
+
+ Status = UTF8StrToUCS2 (TempVolName, &VolumeName);
+
+ if(EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ VolNameLength = StrLen (VolumeName);
+ }
+
+ NeededLength = SIZE_OF_EFI_FILE_SYSTEM_INFO;
+
+ if (VolumeName != NULL) {
+ NeededLength += StrSize (VolumeName);
+ } else {
+ // If we don't have a volume name, we set VolumeLabel to a single null terminator
+ NeededLength += sizeof (CHAR16);
+ }
+
+ if(*BufferSize < NeededLength) {
+ *BufferSize = NeededLength;
+
+ if (VolumeName != NULL) {
+ FreePool (VolumeName);
+ }
+
+ return EFI_BUFFER_TOO_SMALL;
+ }
+
+ TotalBlocks = Part->NumberBlocks;
+
+ FreeBlocks = Ext4MakeBlockNumberFromHalfs (
+ Part,
+ Part->SuperBlock.s_free_blocks_count,
+ Part->SuperBlock.s_free_blocks_count_hi
+ );
+
+ Info->BlockSize = Part->BlockSize;
+ Info->Size = NeededLength;
+ Info->ReadOnly = Part->ReadOnly;
+ Info->VolumeSize = MultU64x32 (TotalBlocks, Part->BlockSize);
+ Info->FreeSpace = MultU64x32 (FreeBlocks, Part->BlockSize);
+
+ if (VolumeName != NULL) {
+ StrCpyS (Info->VolumeLabel, VolNameLength + 1, VolumeName);
+ } else {
+ Info->VolumeLabel[0] = L'\0';
+ }
+
+ if (VolumeName != NULL) {
+ FreePool (VolumeName);
+ }
+
+ *BufferSize = NeededLength;
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Returns information about a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle the requested information is for.
+ @param InformationType The type identifier for the information being requested.
+ @param BufferSize On input, the size of Buffer. On output, the amount of data
+ returned in Buffer. In both cases, the size is measured in bytes.
+ @param Buffer A pointer to the data buffer to return. The buffer's type is
+ indicated by InformationType.
+
+ @retval EFI_SUCCESS The information was returned.
+ @retval EFI_UNSUPPORTED The InformationType is not known.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_BUFFER_TOO_SMALL The BufferSize is too small to read the current directory entry.
+ BufferSize has been updated with the size needed to complete
+ the request.
+**/
+EFI_STATUS
+EFIAPI
+Ext4GetInfo (
+ IN EFI_FILE_PROTOCOL *This,
+ IN EFI_GUID *InformationType,
+ IN OUT UINTN *BufferSize,
+ OUT VOID *Buffer
+ )
+{
+ if (CompareGuid (InformationType, &gEfiFileInfoGuid)) {
+ return Ext4GetFileInfo ((EXT4_FILE *)This, Buffer, BufferSize);
+ }
+
+ if (CompareGuid (InformationType, &gEfiFileSystemInfoGuid)) {
+ return Ext4GetFilesystemInfo (((EXT4_FILE *)This)->Partition, Buffer, BufferSize);
+ }
+
+ return EFI_UNSUPPORTED;
+}
+
+/**
+ Duplicates a file structure.
+
+ @param[in] Original Pointer to the original file.
+
+ @return Pointer to the new file structure.
+**/
+STATIC
+EXT4_FILE *
+Ext4DuplicateFile (
+ IN CONST EXT4_FILE *Original
+ )
+{
+ EXT4_PARTITION *Partition;
+ EXT4_FILE *File;
+
+ Partition = Original->Partition;
+ File = AllocateZeroPool (sizeof (EXT4_FILE));
+
+ if (File == NULL) {
+ return NULL;
+ }
+
+ File->Inode = Ext4AllocateInode (Partition);
+ if (File->Inode == NULL) {
+ FreePool (File);
+ return NULL;
+ }
+
+ CopyMem (File->Inode, Original->Inode, Partition->InodeSize);
+
+ File->FileName = AllocateZeroPool (StrSize (Original->FileName));
+ if (File->FileName == NULL) {
+ FreePool (File->Inode);
+ FreePool (File);
+ return NULL;
+ }
+
+ StrCpyS (File->FileName, StrLen (Original->FileName) + 1, Original->FileName);
+
+ File->Position = 0;
+ Ext4SetupFile (File, Partition);
+ File->InodeNum = Original->InodeNum;
+ File->OpenMode = 0; // Will be filled by other code
+
+ if (!Ext4InitExtentsMap (File)) {
+ FreePool (File->FileName);
+ FreePool (File->Inode);
+ FreePool (File);
+ return NULL;
+ }
+
+ InsertTailList (&Partition->OpenFiles, &File->OpenFilesListNode);
+
+ return File;
+}
+
+/**
+ Sets information about a file.
+
+ @param This A pointer to the EFI_FILE_PROTOCOL instance that is the file
+ handle the information is for.
+ @param InformationType The type identifier for the information being set.
+ @param BufferSize The size, in bytes, of Buffer.
+ @param Buffer A pointer to the data buffer to write. The buffer's type is
+ indicated by InformationType.
+
+ @retval EFI_SUCCESS The information was set.
+ @retval EFI_UNSUPPORTED The InformationType is not known.
+ @retval EFI_NO_MEDIA The device has no medium.
+ @retval EFI_DEVICE_ERROR The device reported an error.
+ @retval EFI_VOLUME_CORRUPTED The file system structures are corrupted.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_INFO_ID and the media is
+ read-only.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_PROTOCOL_SYSTEM_INFO_ID
+ and the media is read only.
+ @retval EFI_WRITE_PROTECTED InformationType is EFI_FILE_SYSTEM_VOLUME_LABEL_ID
+ and the media is read-only.
+ @retval EFI_ACCESS_DENIED An attempt is made to change the name of a file to a
+ file that is already present.
+ @retval EFI_ACCESS_DENIED An attempt is being made to change the EFI_FILE_DIRECTORY
+ Attribute.
+ @retval EFI_ACCESS_DENIED An attempt is being made to change the size of a directory.
+ @retval EFI_ACCESS_DENIED InformationType is EFI_FILE_INFO_ID and the file was opened
+ read-only and an attempt is being made to modify a field
+ other than Attribute.
+ @retval EFI_VOLUME_FULL The volume is full.
+ @retval EFI_BAD_BUFFER_SIZE BufferSize is smaller than the size of the type indicated
+ by InformationType.
+
+**/
+EFI_STATUS
+EFIAPI
+Ext4SetInfo (
+ IN EFI_FILE_PROTOCOL *This,
+ IN EFI_GUID *InformationType,
+ IN UINTN BufferSize,
+ IN VOID *Buffer
+ )
+{
+ EXT4_FILE *File;
+ EXT4_PARTITION *Part;
+
+ File = (EXT4_FILE *)This;
+ Part = File->Partition;
+
+ if (Part->ReadOnly) {
+ return EFI_WRITE_PROTECTED;
+ }
+
+ // Write support
+ return EFI_UNSUPPORTED;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Inode.c b/Features/Ext4Pkg/Ext4Dxe/Inode.c
new file mode 100644
index 0000000000..7db8d22a90
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Inode.c
@@ -0,0 +1,467 @@
+/** @file Inode related routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+
+ EpochToEfiTime copied from EmbeddedPkg/Library/TimeBaseLib.c
+ Copyright (c) 2016, Hisilicon Limited. All rights reserved.
+ Copyright (c) 2016-2019, Linaro Limited. All rights reserved.
+ Copyright (c) 2021, Ampere Computing LLC. All rights reserved.
+**/
+
+#include "Ext4Dxe.h"
+
+#include <Uefi.h>
+
+/**
+ Calculates the checksum of the given inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Inode Pointer to the inode.
+ @param[in] InodeNum Inode number.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateInodeChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_INODE *Inode,
+ IN EXT4_INO_NR InodeNum
+ )
+{
+ UINT32 Crc;
+ UINT16 Dummy;
+ BOOLEAN HasSecondChecksumField;
+ CONST VOID *RestOfInode;
+ UINTN RestOfInodeLength;
+ UINTN Length;
+
+ HasSecondChecksumField = EXT4_INODE_HAS_FIELD (Inode, i_checksum_hi);
+
+ Dummy = 0;
+
+ Crc = Ext4CalculateChecksum (Partition, &InodeNum, sizeof (InodeNum), Partition->InitialSeed);
+ Crc = Ext4CalculateChecksum (Partition, &Inode->i_generation, sizeof (Inode->i_generation), Crc);
+
+ Crc = Ext4CalculateChecksum (
+ Partition,
+ Inode,
+ OFFSET_OF (EXT4_INODE, i_osd2.data_linux.l_i_checksum_lo),
+ Crc
+ );
+
+ Crc = Ext4CalculateChecksum (Partition, &Dummy, sizeof (Dummy), Crc);
+
+ RestOfInode = &Inode->i_osd2.data_linux.l_i_reserved;
+ RestOfInodeLength = Partition->InodeSize - OFFSET_OF (EXT4_INODE, i_osd2.data_linux.l_i_reserved);
+
+ if (HasSecondChecksumField) {
+ Length = OFFSET_OF (EXT4_INODE, i_checksum_hi) - OFFSET_OF (EXT4_INODE, i_osd2.data_linux.l_i_reserved);
+
+ Crc = Ext4CalculateChecksum (Partition, &Inode->i_osd2.data_linux.l_i_reserved, Length, Crc);
+ Crc = Ext4CalculateChecksum (Partition, &Dummy, sizeof (Dummy), Crc);
+
+ // 4 is the size of the i_extra_size field + the size of i_checksum_hi
+ RestOfInodeLength = Partition->InodeSize - EXT4_GOOD_OLD_INODE_SIZE - 4;
+ RestOfInode = &Inode->i_ctime_extra;
+ }
+
+ Crc = Ext4CalculateChecksum (Partition, RestOfInode, RestOfInodeLength, Crc);
+
+ return Crc;
+}
+
+/**
+ Reads from an EXT4 inode.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] File Pointer to the opened file.
+ @param[out] Buffer Pointer to the buffer.
+ @param[in] Offset Offset of the read.
+ @param[in out] Length Pointer to the length of the buffer, in bytes.
+ After a succesful read, it's updated to the number of read bytes.
+
+ @return Status of the read operation.
+**/
+EFI_STATUS
+Ext4Read (
+ IN EXT4_PARTITION *Partition,
+ IN EXT4_FILE *File,
+ OUT VOID *Buffer,
+ IN UINT64 Offset,
+ IN OUT UINTN *Length
+ )
+{
+ // DEBUG((DEBUG_INFO, "Ext4Read[Offset %lu, Length %lu]\n", Offset, *Length));
+ EXT4_INODE *Inode;
+ UINT64 InodeSize;
+ UINT64 CurrentSeek;
+ UINTN RemainingRead;
+ UINTN BeenRead;
+
+ Inode = File->Inode;
+ InodeSize = Ext4InodeSize (Inode);
+ CurrentSeek = Offset;
+ RemainingRead = *Length;
+ BeenRead = 0;
+
+ if(Offset > InodeSize) {
+ return EFI_DEVICE_ERROR;
+ }
+
+ if (RemainingRead > InodeSize - Offset) {
+ RemainingRead = (UINTN)(InodeSize - Offset);
+ }
+
+ while(RemainingRead != 0) {
+ UINTN WasRead;
+ EXT4_EXTENT Extent;
+ UINT32 BlockOff;
+ EFI_STATUS Status;
+ BOOLEAN HasBackingExtent;
+
+ WasRead = 0;
+
+ // The algorithm here is to get the extent corresponding to the current block
+ // and then read as much as we can from the current extent.
+
+ Status = Ext4GetExtent (
+ Partition,
+ File,
+ DivU64x32Remainder (CurrentSeek, Partition->BlockSize, &BlockOff),
+ &Extent
+ );
+
+ if(Status != EFI_SUCCESS && Status != EFI_NO_MAPPING) {
+ return Status;
+ }
+
+ HasBackingExtent = Status != EFI_NO_MAPPING;
+
+ if(!HasBackingExtent) {
+ UINT32 HoleOff;
+ UINTN HoleLen;
+
+ HoleOff = BlockOff;
+ HoleLen = Partition->BlockSize - HoleOff;
+ WasRead = HoleLen > RemainingRead ? RemainingRead : HoleLen;
+ // TODO: Get the hole size and memset all that
+ SetMem (Buffer, WasRead, 0);
+ } else {
+ UINT64 ExtentStartBytes;
+ UINT64 ExtentLengthBytes;
+ UINT64 ExtentLogicalBytes;
+
+ // Our extent offset is the difference between CurrentSeek and ExtentLogicalBytes
+ UINT64 ExtentOffset;
+ UINTN ExtentMayRead;
+
+ ExtentStartBytes = MultU64x32 (LShiftU64 (Extent.ee_start_hi, 32) | Extent.ee_start_lo, Partition->BlockSize);
+ ExtentLengthBytes = Extent.ee_len * Partition->BlockSize;
+ ExtentLogicalBytes = (UINT64)Extent.ee_block * Partition->BlockSize;
+ ExtentOffset = CurrentSeek - ExtentLogicalBytes;
+ ExtentMayRead = (UINTN)(ExtentLengthBytes - ExtentOffset);
+
+ WasRead = ExtentMayRead > RemainingRead ? RemainingRead : ExtentMayRead;
+
+ // DEBUG((DEBUG_INFO, "[ext4] may read %lu, remaining %lu\n", ExtentMayRead, RemainingRead));
+ // DEBUG((DEBUG_INFO, "[ext4] Reading block %lu\n", (ExtentStartBytes + ExtentOffset) / Partition->BlockSize));
+ Status = Ext4ReadDiskIo (Partition, Buffer, WasRead, ExtentStartBytes + ExtentOffset);
+
+ if(EFI_ERROR (Status)) {
+ DEBUG ((
+ DEBUG_ERROR,
+ "[ext4] Error %x reading [%lu, %lu]\n",
+ Status,
+ ExtentStartBytes + ExtentOffset,
+ ExtentStartBytes + ExtentOffset + WasRead - 1
+ ));
+ return Status;
+ }
+ }
+
+ RemainingRead -= WasRead;
+ Buffer = (VOID *)((CHAR8 *)Buffer + WasRead);
+ BeenRead += WasRead;
+ CurrentSeek += WasRead;
+ }
+
+ *Length = BeenRead;
+
+ // DEBUG((DEBUG_INFO, "File length %lu crc %x\n", BeenRead, CalculateCrc32(original, BeenRead)));
+ return EFI_SUCCESS;
+}
+
+/**
+ Allocates a zeroed inode structure.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+
+ @return Pointer to the allocated structure, from the pool,
+ with size Partition->InodeSize.
+**/
+EXT4_INODE *
+Ext4AllocateInode (
+ IN EXT4_PARTITION *Partition
+ )
+{
+ BOOLEAN NeedsToZeroRest;
+ UINT32 InodeSize;
+ EXT4_INODE *Inode;
+
+ NeedsToZeroRest = FALSE;
+ InodeSize = Partition->InodeSize;
+
+ // HACK!: We allocate a structure of at least sizeof(EXT4_INODE), but in the future, when
+ // write support is added and we need to flush inodes to disk, we could have a bit better
+ // distinction between the on-disk inode and a separate, nicer to work with inode struct.
+ if (InodeSize < sizeof (EXT4_INODE)) {
+ InodeSize = sizeof (EXT4_INODE);
+ NeedsToZeroRest = TRUE;
+ }
+
+ Inode = AllocateZeroPool (InodeSize);
+
+ if (!Inode) {
+ return NULL;
+ }
+
+ if (NeedsToZeroRest) {
+ Inode->i_extra_isize = 0;
+ }
+
+ return Inode;
+}
+
+/**
+ Checks if a file is a directory.
+ @param[in] File Pointer to the opened file.
+
+ @return TRUE if file is a directory.
+**/
+BOOLEAN
+Ext4FileIsDir (
+ IN CONST EXT4_FILE *File
+ )
+{
+ return (File->Inode->i_mode & EXT4_INO_TYPE_DIR) == EXT4_INO_TYPE_DIR;
+}
+
+/**
+ Checks if a file is a regular file.
+ @param[in] File Pointer to the opened file.
+
+ @return BOOLEAN TRUE if file is a regular file.
+**/
+BOOLEAN
+Ext4FileIsReg (
+ IN CONST EXT4_FILE *File
+ )
+{
+ return (File->Inode->i_mode & EXT4_INO_TYPE_REGFILE) == EXT4_INO_TYPE_REGFILE;
+}
+
+/**
+ Calculates the physical space used by a file.
+ @param[in] File Pointer to the opened file.
+
+ @return Physical space used by a file, in bytes.
+**/
+UINT64
+Ext4FilePhysicalSpace (
+ EXT4_FILE *File
+ )
+{
+ BOOLEAN HugeFile;
+ UINT64 Blocks;
+
+ HugeFile = Ext4HasRoCompat (File->Partition, EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
+ Blocks = File->Inode->i_blocks;
+
+ if(HugeFile) {
+ Blocks |= LShiftU64 (File->Inode->i_osd2.data_linux.l_i_blocks_high, 32);
+
+ // If HUGE_FILE is enabled and EXT4_HUGE_FILE_FL is set in the inode's flags, each unit
+ // in i_blocks corresponds to an actual filesystem block
+ if(File->Inode->i_flags & EXT4_HUGE_FILE_FL) {
+ return MultU64x32 (Blocks, File->Partition->BlockSize);
+ }
+ }
+
+ // Else, each i_blocks unit corresponds to 512 bytes
+ return MultU64x32 (Blocks, 512);
+}
+
+// Copied from EmbeddedPkg at my mentor's request.
+// The lack of comments and good variable names is frightening...
+
+/**
+ Converts Epoch seconds (elapsed since 1970 JANUARY 01, 00:00:00 UTC) to EFI_TIME.
+
+ @param EpochSeconds Epoch seconds.
+ @param Time The time converted to UEFI format.
+
+**/
+STATIC
+VOID
+EFIAPI
+EpochToEfiTime (
+ IN UINTN EpochSeconds,
+ OUT EFI_TIME *Time
+ )
+{
+ UINTN a;
+ UINTN b;
+ UINTN c;
+ UINTN d;
+ UINTN g;
+ UINTN j;
+ UINTN m;
+ UINTN y;
+ UINTN da;
+ UINTN db;
+ UINTN dc;
+ UINTN dg;
+ UINTN hh;
+ UINTN mm;
+ UINTN ss;
+ UINTN J;
+
+ J = (EpochSeconds / 86400) + 2440588;
+ j = J + 32044;
+ g = j / 146097;
+ dg = j % 146097;
+ c = (((dg / 36524) + 1) * 3) / 4;
+ dc = dg - (c * 36524);
+ b = dc / 1461;
+ db = dc % 1461;
+ a = (((db / 365) + 1) * 3) / 4;
+ da = db - (a * 365);
+ y = (g * 400) + (c * 100) + (b * 4) + a;
+ m = (((da * 5) + 308) / 153) - 2;
+ d = da - (((m + 4) * 153) / 5) + 122;
+
+ Time->Year = (UINT16)(y - 4800 + ((m + 2) / 12));
+ Time->Month = ((m + 2) % 12) + 1;
+ Time->Day = (UINT8)(d + 1);
+
+ ss = EpochSeconds % 60;
+ a = (EpochSeconds - ss) / 60;
+ mm = a % 60;
+ b = (a - mm) / 60;
+ hh = b % 24;
+
+ Time->Hour = (UINT8)hh;
+ Time->Minute = (UINT8)mm;
+ Time->Second = (UINT8)ss;
+ Time->Nanosecond = 0;
+}
+
+// The time format used to (de/en)code timestamp and timestamp_extra is documented on
+// the ext4 docs page in kernel.org
+#define EXT4_EXTRA_TIMESTAMP_MASK ((1 << 2) - 1)
+
+#define EXT4_FILE_GET_TIME_GENERIC(Name, Field) \
+ VOID \
+ Ext4File ## Name (IN EXT4_FILE *File, OUT EFI_TIME *Time) \
+ { \
+ EXT4_INODE *Inode = File->Inode; \
+ UINT64 SecondsEpoch = Inode->Field; \
+ UINT32 Nanoseconds = 0; \
+ \
+ if (EXT4_INODE_HAS_FIELD (Inode, Field ## _extra)) { \
+ SecondsEpoch |= LShiftU64 ((UINT64)(Inode->Field ## _extra & EXT4_EXTRA_TIMESTAMP_MASK), 32); \
+ Nanoseconds = Inode->Field ## _extra >> 2; \
+ } \
+ EpochToEfiTime ((UINTN)SecondsEpoch, Time); \
+ Time->Nanosecond = Nanoseconds; \
+ }
+
+// Note: EpochToEfiTime should be adjusted to take in a UINT64 instead of a UINTN, in order to avoid Y2038
+// on 32-bit systems.
+
+/**
+ Gets the file's last access time.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+**/
+EXT4_FILE_GET_TIME_GENERIC (ATime, i_atime);
+
+/**
+ Gets the file's last (data) modification time.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+**/
+EXT4_FILE_GET_TIME_GENERIC (MTime, i_mtime);
+
+/**
+ Gets the file's creation time.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+**/
+STATIC
+EXT4_FILE_GET_TIME_GENERIC (
+ CrTime, i_crtime
+ );
+
+/**
+ Gets the file's creation time, if possible.
+ @param[in] File Pointer to the opened file.
+ @param[out] Time Pointer to an EFI_TIME structure.
+ In the case where the the creation time isn't recorded,
+ Time is zeroed.
+**/
+VOID
+Ext4FileCreateTime (
+ IN EXT4_FILE *File,
+ OUT EFI_TIME *Time
+ )
+{
+ EXT4_INODE *Inode;
+
+ Inode = File->Inode;
+
+ if (!EXT4_INODE_HAS_FIELD (Inode, i_crtime)) {
+ SetMem (Time, sizeof (EFI_TIME), 0);
+ return;
+ }
+
+ Ext4FileCrTime (File, Time);
+}
+
+/**
+ Checks if the checksum of the inode is correct.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Inode Pointer to the inode.
+ @param[in] InodeNum Inode number.
+
+ @return TRUE if checksum is correct, FALSE if there is corruption.
+**/
+BOOLEAN
+Ext4CheckInodeChecksum (
+ IN CONST EXT4_PARTITION *Partition,
+ IN CONST EXT4_INODE *Inode,
+ IN EXT4_INO_NR InodeNum
+ )
+{
+ UINT32 Csum;
+ UINT32 DiskCsum;
+
+ if(!Ext4HasMetadataCsum (Partition)) {
+ return TRUE;
+ }
+
+ Csum = Ext4CalculateInodeChecksum (Partition, Inode, InodeNum);
+
+ DiskCsum = Inode->i_osd2.data_linux.l_i_checksum_lo;
+
+ if (EXT4_INODE_HAS_FIELD (Inode, i_checksum_hi)) {
+ DiskCsum |= ((UINT32)Inode->i_checksum_hi) << 16;
+ } else {
+ // Only keep the lower bits for the comparison if the checksum is 16 bits.
+ Csum &= 0xffff;
+ }
+
+ #if 0
+ DEBUG ((DEBUG_INFO, "[ext4] Inode %d csum %x vs %x\n", InodeNum, Csum, DiskCsum));
+ #endif
+
+ return Csum == DiskCsum;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Partition.c b/Features/Ext4Pkg/Ext4Dxe/Partition.c
new file mode 100644
index 0000000000..ddacd7cb51
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Partition.c
@@ -0,0 +1,122 @@
+/** @file Driver entry point
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+/**
+ Opens an ext4 partition and installs the Simple File System protocol.
+
+ @param[in] DeviceHandle Handle to the block device.
+ @param[in] DiskIo Pointer to an EFI_DISK_IO_PROTOCOL.
+ @param[in opt] DiskIo2 Pointer to an EFI_DISK_IO2_PROTOCOL, if supported.
+ @param[in] BlockIo Pointer to an EFI_BLOCK_IO_PROTOCOL.
+
+ @retval EFI_SUCCESS The opening was successful.
+ !EFI_SUCCESS Opening failed.
+**/
+EFI_STATUS
+Ext4OpenPartition (
+ IN EFI_HANDLE DeviceHandle,
+ IN EFI_DISK_IO_PROTOCOL *DiskIo,
+ IN OPTIONAL EFI_DISK_IO2_PROTOCOL *DiskIo2,
+ IN EFI_BLOCK_IO_PROTOCOL *BlockIo
+ )
+{
+ EXT4_PARTITION *Part;
+ EFI_STATUS Status;
+
+ Part = AllocateZeroPool (sizeof (*Part));
+
+ if(Part == NULL) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ InitializeListHead (&Part->OpenFiles);
+
+ Part->BlockIo = BlockIo;
+ Part->DiskIo = DiskIo;
+ Part->DiskIo2 = DiskIo2;
+
+ Status = Ext4OpenSuperblock (Part);
+
+ if(EFI_ERROR (Status)) {
+ FreePool (Part);
+ return Status;
+ }
+
+ Part->Interface.Revision = EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_REVISION;
+ Part->Interface.OpenVolume = Ext4OpenVolume;
+ Status = gBS->InstallMultipleProtocolInterfaces (
+ &DeviceHandle,
+ &gEfiSimpleFileSystemProtocolGuid,
+ &Part->Interface,
+ NULL
+ );
+
+ if(EFI_ERROR (Status)) {
+ FreePool (Part);
+ return Status;
+ }
+
+ return EFI_SUCCESS;
+}
+
+/**
+ Sets up the protocol and metadata of a file that is being opened.
+
+ @param[in out] File Pointer to the file.
+ @param[in] Partition Pointer to the opened partition.
+**/
+VOID
+Ext4SetupFile (
+ IN OUT EXT4_FILE *File, EXT4_PARTITION *Partition
+ )
+{
+ // TODO: Support revision 2 (needs DISK_IO2 + asynchronous IO)
+ File->Protocol.Revision = EFI_FILE_PROTOCOL_REVISION;
+ File->Protocol.Open = Ext4Open;
+ File->Protocol.Close = Ext4Close;
+ File->Protocol.Delete = Ext4Delete;
+ File->Protocol.Read = Ext4ReadFile;
+ File->Protocol.Write = Ext4WriteFile;
+ File->Protocol.SetPosition = Ext4SetPosition;
+ File->Protocol.GetPosition = Ext4GetPosition;
+ File->Protocol.GetInfo = Ext4GetInfo;
+ File->Protocol.SetInfo = Ext4SetInfo;
+
+ File->Partition = Partition;
+}
+
+/**
+ Unmounts and frees an ext4 partition.
+
+ @param[in] Partition Pointer to the opened partition.
+
+ @retval Status of the unmount.
+**/
+EFI_STATUS
+Ext4UnmountAndFreePartition (
+ IN EXT4_PARTITION *Partition
+ )
+{
+ LIST_ENTRY *Entry;
+ LIST_ENTRY *NextEntry;
+ EXT4_FILE *File;
+
+ Partition->Unmounting = TRUE;
+ Ext4CloseInternal (Partition->Root);
+
+ BASE_LIST_FOR_EACH_SAFE (Entry, NextEntry, &Partition->OpenFiles) {
+ File = EXT4_FILE_FROM_OPEN_FILES_NODE (Entry);
+
+ Ext4CloseInternal (File);
+ }
+
+ FreePool (Partition->BlockGroups);
+ FreePool (Partition);
+
+ return EFI_SUCCESS;
+}
diff --git a/Features/Ext4Pkg/Ext4Dxe/Superblock.c b/Features/Ext4Pkg/Ext4Dxe/Superblock.c
new file mode 100644
index 0000000000..22a33ce1f8
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Dxe/Superblock.c
@@ -0,0 +1,281 @@
+/** @file Superblock managing routines
+
+ Copyright (c) 2021 Pedro Falcato All rights reserved.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include "Ext4Dxe.h"
+
+STATIC CONST UINT32 gSupportedCompatFeat = EXT4_FEATURE_COMPAT_EXT_ATTR;
+
+STATIC CONST UINT32 gSupportedRoCompatFeat =
+ EXT4_FEATURE_RO_COMPAT_DIR_NLINK | EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE |
+ EXT4_FEATURE_RO_COMPAT_HUGE_FILE | EXT4_FEATURE_RO_COMPAT_LARGE_FILE |
+ EXT4_FEATURE_RO_COMPAT_GDT_CSUM | EXT4_FEATURE_RO_COMPAT_METADATA_CSUM | EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER;
+// TODO: Add btree support
+STATIC CONST UINT32 gSupportedIncompatFeat =
+ EXT4_FEATURE_INCOMPAT_64BIT | EXT4_FEATURE_INCOMPAT_DIRDATA |
+ EXT4_FEATURE_INCOMPAT_FLEX_BG | EXT4_FEATURE_INCOMPAT_FILETYPE |
+ EXT4_FEATURE_INCOMPAT_EXTENTS | EXT4_FEATURE_INCOMPAT_LARGEDIR |
+ EXT4_FEATURE_INCOMPAT_MMP;
+
+// TODO: Add meta_bg support
+
+// Note: We ignore MMP because it's impossible that it's mapped elsewhere,
+// I think (unless there's some sort of network setup where we're accessing a remote partition).
+
+/**
+ Does brief validation of the ext4 superblock.
+
+ @param[in] Sb Pointer to the read superblock.
+
+ @return TRUE if a valid ext4 superblock, else FALSE.
+**/
+BOOLEAN
+Ext4SuperblockValidate (
+ CONST EXT4_SUPERBLOCK *Sb
+ )
+{
+ if(Sb->s_magic != EXT4_SIGNATURE) {
+ return FALSE;
+ }
+
+ // TODO: We should try to support EXT2/3 partitions too
+ if(Sb->s_rev_level != EXT4_DYNAMIC_REV && Sb->s_rev_level != EXT4_GOOD_OLD_REV) {
+ return FALSE;
+ }
+
+ // TODO: Is this correct behaviour? Imagine the power cuts out, should the system fail to boot because
+ // we're scared of touching something corrupt?
+ if((Sb->s_state & EXT4_FS_STATE_UNMOUNTED) == 0) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ Calculates the superblock's checksum.
+
+ @param[in] Partition Pointer to the opened partition.
+ @param[in] Sb Pointer to the superblock.
+
+ @return The superblock's checksum.
+**/
+STATIC UINT32
+Ext4CalculateSuperblockChecksum (
+ EXT4_PARTITION *Partition, CONST EXT4_SUPERBLOCK *Sb
+ )
+{
+ // Most checksums require us to go through a dummy 0 as part of the requirement
+ // that the checksum is done over a structure with its checksum field = 0.
+ UINT32 Checksum;
+
+ Checksum = Ext4CalculateChecksum (
+ Partition,
+ Sb,
+ OFFSET_OF (EXT4_SUPERBLOCK, s_checksum),
+ ~0U
+ );
+
+ return Checksum;
+}
+
+/**
+ Verifies that the superblock's checksum is valid.
+
+ @param[in] Partition Pointer to the opened partition.
+ @param[in] Sb Pointer to the superblock.
+
+ @return The superblock's checksum.
+**/
+STATIC BOOLEAN
+Ext4VerifySuperblockChecksum (
+ EXT4_PARTITION *Partition, CONST EXT4_SUPERBLOCK *Sb
+ )
+{
+ if(!Ext4HasMetadataCsum (Partition)) {
+ return TRUE;
+ }
+
+ return Sb->s_checksum == Ext4CalculateSuperblockChecksum (Partition, Sb);
+}
+
+/**
+ Opens and parses the superblock.
+
+ @param[out] Partition Partition structure to fill with filesystem details.
+ @retval EFI_SUCCESS Parsing was succesful and the partition is a
+ valid ext4 partition.
+**/
+EFI_STATUS
+Ext4OpenSuperblock (
+ OUT EXT4_PARTITION *Partition
+ )
+{
+ UINT32 Index;
+ EFI_STATUS Status;
+ EXT4_SUPERBLOCK *Sb;
+ UINT32 NrBlocksRem;
+ UINTN NrBlocks;
+ UINT32 UnsupportedRoCompat;
+
+ Status = Ext4ReadDiskIo (
+ Partition,
+ &Partition->SuperBlock,
+ sizeof (EXT4_SUPERBLOCK),
+ EXT4_SUPERBLOCK_OFFSET
+ );
+
+ if (EFI_ERROR (Status)) {
+ return Status;
+ }
+
+ Sb = &Partition->SuperBlock;
+
+ if (!Ext4SuperblockValidate (Sb)) {
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ if (Sb->s_rev_level == EXT4_DYNAMIC_REV) {
+ Partition->FeaturesCompat = Sb->s_feature_compat;
+ Partition->FeaturesIncompat = Sb->s_feature_incompat;
+ Partition->FeaturesRoCompat = Sb->s_feature_ro_compat;
+ Partition->InodeSize = Sb->s_inode_size;
+ } else {
+ // GOOD_OLD_REV
+ Partition->FeaturesCompat = Partition->FeaturesIncompat = Partition->FeaturesRoCompat = 0;
+ Partition->InodeSize = EXT4_GOOD_OLD_INODE_SIZE;
+ }
+
+ // Now, check for the feature set of the filesystem
+ // It's essential to check for this to avoid filesystem corruption and to avoid
+ // accidentally opening an ext2/3/4 filesystem we don't understand, which would be disasterous.
+
+ if (Partition->FeaturesIncompat & ~gSupportedIncompatFeat) {
+ DEBUG ((DEBUG_INFO, "[Ext4] Unsupported %lx\n", Partition->FeaturesIncompat & ~gSupportedIncompatFeat));
+ return EFI_UNSUPPORTED;
+ }
+
+ // This should be removed once we add ext2/3 support in the future.
+ if ((Partition->FeaturesIncompat & EXT4_FEATURE_INCOMPAT_EXTENTS) == 0) {
+ return EFI_UNSUPPORTED;
+ }
+
+ // At the time of writing, it's the only supported checksum.
+ if (Partition->FeaturesCompat & EXT4_FEATURE_RO_COMPAT_METADATA_CSUM &&
+ Sb->s_checksum_type != EXT4_CHECKSUM_CRC32C) {
+ return EFI_UNSUPPORTED;
+ }
+
+ if (Partition->FeaturesIncompat & EXT4_FEATURE_INCOMPAT_CSUM_SEED) {
+ Partition->InitialSeed = Sb->s_checksum_seed;
+ } else {
+ Partition->InitialSeed = Ext4CalculateChecksum (Partition, Sb->s_uuid, 16, ~0U);
+ }
+
+ UnsupportedRoCompat = Partition->FeaturesRoCompat & ~gSupportedRoCompatFeat;
+
+ if (UnsupportedRoCompat != 0) {
+ DEBUG ((DEBUG_INFO, "[Ext4] Unsupported ro compat %x\n", UnsupportedRoCompat));
+ Partition->ReadOnly = TRUE;
+ }
+
+ (VOID)gSupportedCompatFeat;
+
+ DEBUG ((DEBUG_INFO, "Read only = %u\n", Partition->ReadOnly));
+
+ Partition->BlockSize = (UINT32)LShiftU64 (1024, Sb->s_log_block_size);
+
+ // The size of a block group can also be calculated as 8 * Partition->BlockSize
+ if(Sb->s_blocks_per_group != 8 * Partition->BlockSize) {
+ return EFI_UNSUPPORTED;
+ }
+
+ Partition->NumberBlocks = Ext4MakeBlockNumberFromHalfs (Partition, Sb->s_blocks_count, Sb->s_blocks_count_hi);
+ Partition->NumberBlockGroups = DivU64x32 (Partition->NumberBlocks, Sb->s_blocks_per_group);
+
+ DEBUG ((
+ DEBUG_INFO,
+ "[ext4] Number of blocks = %lu\n[ext4] Number of block groups: %lu\n",
+ Partition->NumberBlocks,
+ Partition->NumberBlockGroups
+ ));
+
+ if (Ext4Is64Bit (Partition)) {
+ Partition->DescSize = Sb->s_desc_size;
+ } else {
+ Partition->DescSize = EXT4_OLD_BLOCK_DESC_SIZE;
+ }
+
+ if (Partition->DescSize < EXT4_64BIT_BLOCK_DESC_SIZE && Ext4Is64Bit (Partition)) {
+ // 64 bit filesystems need DescSize to be 64 bytes
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ if (!Ext4VerifySuperblockChecksum (Partition, Sb)) {
+ DEBUG ((DEBUG_ERROR, "[ext4] Bad superblock checksum %lx\n", Ext4CalculateSuperblockChecksum (Partition, Sb)));
+ return EFI_VOLUME_CORRUPTED;
+ }
+
+ NrBlocks = (UINTN)DivU64x32Remainder (
+ MultU64x32 (Partition->NumberBlockGroups, Partition->DescSize),
+ Partition->BlockSize,
+ &NrBlocksRem
+ );
+
+ if(NrBlocksRem != 0) {
+ NrBlocks++;
+ }
+
+ Partition->BlockGroups = Ext4AllocAndReadBlocks (Partition, NrBlocks, Partition->BlockSize == 1024 ? 2 : 1);
+
+ if (!Partition->BlockGroups) {
+ return EFI_OUT_OF_RESOURCES;
+ }
+
+ for (Index = 0; Index < Partition->NumberBlockGroups; Index++) {
+ EXT4_BLOCK_GROUP_DESC *Desc;
+
+ Desc = Ext4GetBlockGroupDesc (Partition, Index);
+ if (!Ext4VerifyBlockGroupDescChecksum (Partition, Desc, Index)) {
+ DEBUG ((DEBUG_INFO, "[ext4] Block group descriptor %u has an invalid checksum\n", Index));
+ return EFI_VOLUME_CORRUPTED;
+ }
+ }
+
+ // Note that the cast below is completely safe, because EXT4_FILE is a specialisation of EFI_FILE_PROTOCOL
+ Status = Ext4OpenVolume (&Partition->Interface, (EFI_FILE_PROTOCOL **)&Partition->Root);
+
+ DEBUG ((DEBUG_INFO, "[ext4] Root File %p\n", Partition->Root));
+ return Status;
+}
+
+/**
+ Calculates the checksum of the given buffer.
+ @param[in] Partition Pointer to the opened EXT4 partition.
+ @param[in] Buffer Pointer to the buffer.
+ @param[in] Length Length of the buffer, in bytes.
+ @param[in] InitialValue Initial value of the CRC.
+
+ @return The checksum.
+**/
+UINT32
+Ext4CalculateChecksum (
+ IN CONST EXT4_PARTITION *Partition, IN CONST VOID *Buffer, IN UINTN Length,
+ IN UINT32 InitialValue
+ )
+{
+ if(!Ext4HasMetadataCsum (Partition)) {
+ return 0;
+ }
+
+ switch(Partition->SuperBlock.s_checksum_type) {
+ case EXT4_CHECKSUM_CRC32C:
+ // For some reason, EXT4 really likes non-inverted CRC32C checksums, so we stick to that here.
+ return ~CalculateCrc32c(Buffer, Length, ~InitialValue);
+ default:
+ UNREACHABLE ();
+ return 0;
+ }
+}
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [Patch v2 3/3] Ext4Pkg: Add .DSC file.
2021-08-07 22:05 [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Pedro Falcato
2021-08-07 22:05 ` [Patch v2 1/3] Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni Pedro Falcato
2021-08-07 22:05 ` [Patch v2 2/3] Ext4Pkg: Add Ext4Dxe driver Pedro Falcato
@ 2021-08-07 22:05 ` Pedro Falcato
2021-08-11 16:43 ` [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Michael D Kinney
3 siblings, 0 replies; 5+ messages in thread
From: Pedro Falcato @ 2021-08-07 22:05 UTC (permalink / raw)
To: devel; +Cc: Pedro Falcato, Leif Lindholm, Michael D Kinney, Bret Barkelew
This file is required to build Ext4Pkg.
Cc: Leif Lindholm <leif@nuviainc.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
---
Features/Ext4Pkg/Ext4Pkg.dsc | 68 ++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
create mode 100644 Features/Ext4Pkg/Ext4Pkg.dsc
diff --git a/Features/Ext4Pkg/Ext4Pkg.dsc b/Features/Ext4Pkg/Ext4Pkg.dsc
new file mode 100644
index 0000000000..62cb4e69cf
--- /dev/null
+++ b/Features/Ext4Pkg/Ext4Pkg.dsc
@@ -0,0 +1,68 @@
+## @file
+# Ext4 Package
+#
+# This package provides libraries and drivers related to the ext4 filesystem implementation.
+# More details are available at: https://www.kernel.org/doc/html/v5.4/filesystems/ext4/index.html
+#
+# Copyright (c) 2021 Pedro Falcato
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+
+[Defines]
+ PLATFORM_NAME = Ext4
+ PLATFORM_GUID = 6B4BF998-668B-46D3-BCFA-971F99F8708C
+ PLATFORM_VERSION = 0.1
+ DSC_SPECIFICATION = 0x00010005
+ SUPPORTED_ARCHITECTURES = IA32|X64|EBC|ARM|AARCH64|RISCV64
+ OUTPUT_DIRECTORY = Build/Ext4Pkg
+ BUILD_TARGETS = DEBUG|RELEASE|NOOPT
+ SKUID_IDENTIFIER = DEFAULT
+
+[BuildOptions]
+ *_*_*_CC_FLAGS = -D DISABLE_NEW_DEPRECATED_INTERFACES
+
+[LibraryClasses]
+ #
+ # Entry Point Libraries
+ #
+ UefiDriverEntryPoint|MdePkg/Library/UefiDriverEntryPoint/UefiDriverEntryPoint.inf
+ #
+ # Common Libraries
+ #
+ BaseLib|MdePkg/Library/BaseLib/BaseLib.inf
+ BaseMemoryLib|MdePkg/Library/BaseMemoryLib/BaseMemoryLib.inf
+ UefiLib|MdePkg/Library/UefiLib/UefiLib.inf
+ PrintLib|MdePkg/Library/BasePrintLib/BasePrintLib.inf
+ PcdLib|MdePkg/Library/BasePcdLibNull/BasePcdLibNull.inf
+ MemoryAllocationLib|MdePkg/Library/UefiMemoryAllocationLib/UefiMemoryAllocationLib.inf
+ UefiBootServicesTableLib|MdePkg/Library/UefiBootServicesTableLib/UefiBootServicesTableLib.inf
+ UefiRuntimeServicesTableLib|MdePkg/Library/UefiRuntimeServicesTableLib/UefiRuntimeServicesTableLib.inf
+ DebugLib|MdePkg/Library/BaseDebugLibNull/BaseDebugLibNull.inf
+ DebugPrintErrorLevelLib|MdePkg/Library/BaseDebugPrintErrorLevelLib/BaseDebugPrintErrorLevelLib.inf
+ DevicePathLib|MdePkg/Library/UefiDevicePathLib/UefiDevicePathLib.inf
+ OrderedCollectionLib|MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.inf
+ BaseUcs2Utf8Lib|RedfishPkg/Library/BaseUcs2Utf8Lib/BaseUcs2Utf8Lib.inf
+
+###################################################################################################
+#
+# Components Section - list of the modules and components that will be processed by compilation
+# tools and the EDK II tools to generate PE32/PE32+/Coff image files.
+#
+# Note: The EDK II DSC file is not used to specify how compiled binary images get placed
+# into firmware volume images. This section is just a list of modules to compile from
+# source into UEFI-compliant binaries.
+# It is the FDF file that contains information on combining binary files into firmware
+# volume images, whose concept is beyond UEFI and is described in PI specification.
+# Binary modules do not need to be listed in this section, as they should be
+# specified in the FDF file. For example: Shell binary (Shell_Full.efi), FAT binary (Fat.efi),
+# Logo (Logo.bmp), and etc.
+# There may also be modules listed in this section that are not required in the FDF file,
+# When a module listed here is excluded from FDF file, then UEFI-compliant binary will be
+# generated for it, but the binary will not be put into any firmware volume.
+#
+###################################################################################################
+
+[Components]
+ Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
--
2.32.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg
2021-08-07 22:05 [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Pedro Falcato
` (2 preceding siblings ...)
2021-08-07 22:05 ` [Patch v2 3/3] Ext4Pkg: Add .DSC file Pedro Falcato
@ 2021-08-11 16:43 ` Michael D Kinney
3 siblings, 0 replies; 5+ messages in thread
From: Michael D Kinney @ 2021-08-11 16:43 UTC (permalink / raw)
To: Pedro Falcato, devel@edk2.groups.io, Kinney, Michael D
Cc: Leif Lindholm, Bret Barkelew
Hi Pedro,
Really good updates. Here are a few comments on V2:
1) I see use of "inline" on some functions. Those are not required
and should be removed. The compiler options used for release
builds always maximize optimization with inlining used by the
compiler if that provides the best optimization.
2) Code style issue for function declarations.
Align types and parameter names in columns
2 spaces between type name and parameter name.
Here is one example (please review all functions):
EFI_STATUS
Ext4ReadDiskIo (
IN EXT4_PARTITION *Partition,
OUT VOID *Buffer,
IN UINTN Length,
IN UINT64 Offset
);
Should be:
EFI_STATUS
Ext4ReadDiskIo (
IN EXT4_PARTITION *Partition,
OUT VOID *Buffer,
IN UINTN Length,
IN UINT64 Offset
);
3) Code style issue.
EFIAPI should always be on its own line.
Here is one example (please review all functions):
EFI_STATUS EFIAPI
Ext4Close (
IN EFI_FILE_PROTOCOL *This
);
Should be:
EFI_STATUS
EFIAPI
Ext4Close (
IN EFI_FILE_PROTOCOL *This
);
4) Some @param comments missing [in], [out], or [in out] decorator
5) What is #if DEBUG_EXTENT_CACHE. We try not to use any ifdefs
and instead convert them to PCD Feature Flags if we need build
time enable/disable of a feature.
I also see a couple #if 0 statements. Those should also be
removed or converted to a PCD Feature Flag if it is something
that is an optional feature. Or converted to DEBUG_CODE()
if it is something that should only be enabled when DEBUG_CODE()
feature is enabled.
6) I see a 12 TODO comments. Can you write up a separate email
with the questions you need answered to address each of those
TODOs? The version committed should not have any remaining
TODO comments. Instead, if there are additional features that
need to be considered for the future, those should be entered
as TianoCore Bugzillas.
7) I see a few places where there are commented out DEBUG() messages
These should either be removed or changed to a debug level that
is normally disabled (DEBUG_VERBOSE or DEBUG_FS) and can be
optionally enabled to debug a specific issue. Here is an example:
EFI_STATUS
Ext4Read (
IN EXT4_PARTITION *Partition,
IN EXT4_FILE *File,
OUT VOID *Buffer,
IN UINT64 Offset,
IN OUT UINTN *Length
)
{
// DEBUG((DEBUG_INFO, "Ext4Read[Offset %lu, Length %lu]\n", Offset, *Length));
EXT4_INODE *Inode;
8) All function local variables must be declared at the beginning of
a function. Ext4Read() is an example where I see additional variables
being declared in the scope of a while and if/else statements.
9) I see places where @file is followed by the brief description of the file
on the same line. The brief description of a file should go on the next line.
10) I see one "HACK!" comment. Looks like it is related to an assumption for
read-only vs read/write capabilities in this driver. Perhaps update the
comment to state that the current implementation assumes read-only and
enter a TianoCore Bugzilla feature request to add read/write support
in the future and note the places in the current driver where read-only
assumptions need to be addressed to add read/write capability.
Thanks,
Mike
> -----Original Message-----
> From: Pedro Falcato <pedro.falcato@gmail.com>
> Sent: Saturday, August 7, 2021 3:06 PM
> To: devel@edk2.groups.io
> Cc: Pedro Falcato <pedro.falcato@gmail.com>; Leif Lindholm <leif@nuviainc.com>; Kinney, Michael D
> <michael.d.kinney@intel.com>; Bret Barkelew <Bret.Barkelew@microsoft.com>
> Subject: [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg
>
> This patch-set adds Ext4Pkg, a package designed to hold various drivers and
> utilities related to the EXT4 filesystem.
>
> Right now, it holds a single read-only UEFI EXT4 driver (Ext4Dxe), which consumes the
> DISK_IO, BLOCK_IO and DISK_IO2 protocols and produce EFI_FILE_PROTOCOL and
> EFI_SIMPLE_FILE_SYSTEM_PROTOCOL; this driver allows the mounting of EXT4 partitions and
> the reading of their contents.
>
> Relevant RFC discussion, which includes a more in-depth walkthrough of EXT4 internals and
> driver limitations is available at https://edk2.groups.io/g/devel/topic/84368561.
>
> This patch set is version 2 and attempts to address issues raised by the
> community in v1's code review.
>
> Cc: Leif Lindholm <leif@nuviainc.com>
> Cc: Michael D Kinney <michael.d.kinney@intel.com>
> Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
>
> Pedro Falcato (3):
> Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni.
> Ext4Pkg: Add Ext4Dxe driver.
> Ext4Pkg: Add .DSC file.
>
> Features/Ext4Pkg/Ext4Dxe/BlockGroup.c | 207 +++++
> Features/Ext4Pkg/Ext4Dxe/Collation.c | 171 ++++
> Features/Ext4Pkg/Ext4Dxe/Crc16.c | 74 ++
> Features/Ext4Pkg/Ext4Dxe/Crc32c.c | 83 ++
> Features/Ext4Pkg/Ext4Dxe/Directory.c | 513 +++++++++++
> Features/Ext4Pkg/Ext4Dxe/DiskUtil.c | 106 +++
> Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h | 455 ++++++++++
> Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c | 789 +++++++++++++++++
> Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h | 1136 +++++++++++++++++++++++++
> Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf | 149 ++++
> Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni | 15 +
> Features/Ext4Pkg/Ext4Dxe/Extents.c | 618 ++++++++++++++
> Features/Ext4Pkg/Ext4Dxe/File.c | 786 +++++++++++++++++
> Features/Ext4Pkg/Ext4Dxe/Inode.c | 467 ++++++++++
> Features/Ext4Pkg/Ext4Dxe/Partition.c | 122 +++
> Features/Ext4Pkg/Ext4Dxe/Superblock.c | 281 ++++++
> Features/Ext4Pkg/Ext4Pkg.dec | 17 +
> Features/Ext4Pkg/Ext4Pkg.dsc | 68 ++
> Features/Ext4Pkg/Ext4Pkg.uni | 14 +
> 19 files changed, 6071 insertions(+)
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/BlockGroup.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Collation.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc16.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Crc32c.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Directory.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/DiskUtil.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Disk.h
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.h
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.inf
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Ext4Dxe.uni
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Extents.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/File.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Inode.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Partition.c
> create mode 100644 Features/Ext4Pkg/Ext4Dxe/Superblock.c
> create mode 100644 Features/Ext4Pkg/Ext4Pkg.dec
> create mode 100644 Features/Ext4Pkg/Ext4Pkg.dsc
> create mode 100644 Features/Ext4Pkg/Ext4Pkg.uni
>
> --
> 2.32.0
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-08-11 16:47 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2021-08-07 22:05 [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Pedro Falcato
2021-08-07 22:05 ` [Patch v2 1/3] Ext4Pkg: Add Ext4Pkg.dec and Ext4Pkg.uni Pedro Falcato
2021-08-07 22:05 ` [Patch v2 2/3] Ext4Pkg: Add Ext4Dxe driver Pedro Falcato
2021-08-07 22:05 ` [Patch v2 3/3] Ext4Pkg: Add .DSC file Pedro Falcato
2021-08-11 16:43 ` [Patch v2 0/3] Ext4Pkg: Add Ext4Pkg Michael D Kinney
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