Re: [edk2-platforms][PATCH V1 1/5] Platform/ARM/Morello: Add Platform library implementation

["Sami Mujawar" <sami.mujawar@arm.com>]

Hi Chandni,

Please find my response inline marked [SAMI].

Regards,

Sami Mujawar

-----Original Message-----
From: Chandni Cherukuri <chandni.cherukuri@arm.com> 
Sent: 24 February 2021 01:12 PM
To: devel@edk2.groups.io
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>; Leif Lindholm <leif@nuviainc.com>; Sami Mujawar <Sami.Mujawar@arm.com>
Subject: [edk2-platforms][PATCH V1 1/5] Platform/ARM/Morello: Add Platform library implementation

From: Anurag Koul <anurag.koul@arm.com>

This patch adds initial Morello Platform Library support.
It includes virtual memory map and helper functions for
platform initialization.

Co-authored-by: Chandni Cherukuri <chandni.cherukuri@arm.com>
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>
---
 Platform/ARM/Morello/Library/PlatformLib/PlatformLib.inf  |  52 ++++++
 Platform/ARM/Morello/Include/MorelloPlatform.h            |  67 +++++++
 Platform/ARM/Morello/Library/PlatformLib/PlatformLib.c    |  66 +++++++
 Platform/ARM/Morello/Library/PlatformLib/PlatformLibMem.c | 194 ++++++++++++++++++++
 Platform/ARM/Morello/Library/PlatformLib/AArch64/Helper.S |  83 +++++++++
 5 files changed, 462 insertions(+)

diff --git a/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.inf b/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.inf
new file mode 100644
index 000000000000..2066d1f3a3f8
--- /dev/null
+++ b/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.inf
@@ -0,0 +1,52 @@
+## @file
+#
+#  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+#
+#  SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+##
+
+[Defines]
+  INF_VERSION                    = 0x0001001A
+  BASE_NAME                      = ArmMorelloLib
+  FILE_GUID                      = 36853D86-7200-47B4-9408-E962A00963FD
+  MODULE_TYPE                    = BASE
+  VERSION_STRING                 = 1.0
+  LIBRARY_CLASS                  = ArmPlatformLib
+
+[Packages]
+  ArmPkg/ArmPkg.dec
+  ArmPlatformPkg/ArmPlatformPkg.dec
+  MdeModulePkg/MdeModulePkg.dec
+  MdePkg/MdePkg.dec
+  Platform/ARM/Morello/MorelloPlatform.dec
+
+[Sources.common]
+  PlatformLibMem.c
+  PlatformLib.c
[SAMI] Reorder in alphabetical order. Same for the FixedPcd section below.
[/SAMI]
+
+[Sources.AARCH64]
+  AArch64/Helper.S | GCC
+
+[FixedPcd]
+  gArmTokenSpaceGuid.PcdArmPrimaryCore
+  gArmTokenSpaceGuid.PcdArmPrimaryCoreMask
+  gArmTokenSpaceGuid.PcdSystemMemoryBase
+  gArmTokenSpaceGuid.PcdSystemMemorySize
+
+  gArmMorelloTokenSpaceGuid.PcdDramBlock2Base
+
+  gArmMorelloTokenSpaceGuid.PcdPciBusMin
+  gArmMorelloTokenSpaceGuid.PcdPciBusMax
+  gArmMorelloTokenSpaceGuid.PcdPciMmio32Base
+  gArmMorelloTokenSpaceGuid.PcdPciMmio32Size
+  gArmMorelloTokenSpaceGuid.PcdPciMmio64Base
+  gArmMorelloTokenSpaceGuid.PcdPciMmio64Size
+  gArmMorelloTokenSpaceGuid.PcdPciExpressBaseAddress
+  gArmMorelloTokenSpaceGuid.PcdPciIoSize
+
+[Guids]
+  gEfiHobListGuid          ## CONSUMES  ## SystemTable
+
+[Ppis]
+  gArmMpCoreInfoPpiGuid
diff --git a/Platform/ARM/Morello/Include/MorelloPlatform.h b/Platform/ARM/Morello/Include/MorelloPlatform.h
new file mode 100644
index 000000000000..f61cfe7f9ee8
--- /dev/null
+++ b/Platform/ARM/Morello/Include/MorelloPlatform.h
@@ -0,0 +1,67 @@
+/** @file
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#ifndef MORELLO_PLATFORM_H__
+#define MORELLO_PLATFORM_H__
[SAMI] See https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/5_source_files/53_include_files#5-3-5-all-include-file-contents-must-be-protected-by-a-include-guard
There is a ECC patch that has been recently merged to catch these issues. I would recommend that you run the ECC tool on the files/folders introduced in this patch series.
e.g To run ecc on a folder you could use:
  python edk2\BaseTools\Source\Python\Ecc\EccMain.py -c edk2\BaseTools\Source\Python\Ecc\config.ini -e edk2\BaseTools\Source\Python\Ecc\exception.xml -r Ecc.csv  -t <FolderPath>
[/SAMI]

+
+#define MORELLO_DRAM_BLOCK1_SIZE               SIZE_2GB
+
+// ****************************************************************************
+// Platform Memory Map
+// ****************************************************************************
+
+// SubSystem Peripherals - UART0
+#define MORELLO_UART0_BASE                     0x2A400000
+#define MORELLO_UART0_SZ                       SIZE_64KB
+
+// SubSystem Peripherals - UART1
+#define MORELLO_UART1_BASE                     0x2A410000
+#define MORELLO_UART1_SZ                       SIZE_64KB
+
+// SubSystem Peripherals - Generic Watchdog
+#define MORELLO_GENERIC_WDOG_BASE              0x2A440000
+#define MORELLO_GENERIC_WDOG_SZ                SIZE_128KB
+
+// SubSystem Peripherals - GIC(600)
+#define MORELLO_GIC_BASE                       0x30000000
+#define MORELLO_GICR_BASE                      0x300C0000
+#define MORELLO_GIC_SZ                         SIZE_256KB
+#define MORELLO_GICR_SZ                        SIZE_1MB
+
+// SubSystem non-secure SRAM
+#define MORELLO_NON_SECURE_SRAM_BASE           0x06000000
+#define MORELLO_NON_SECURE_SRAM_SZ             SIZE_64KB
+
+// AXI Expansion peripherals
+#define MORELLO_EXP_PERIPH_BASE                0x1C000000
+#define MORELLO_EXP_PERIPH_BASE_SZ             0x1300000
+
+// Platform information structure base address
+#define MORELLO_PLAT_INFO_STRUCT_BASE          MORELLO_NON_SECURE_SRAM_BASE
+
+/*
+ * Platform information structure stored in Non-secure SRAM. Platform
+ * information are passed from the trusted firmware with the below structure
+ * format. The elements of MORELLO_PLAT_INFO should be always in sync with
+ * the lower level firmware.
+ */
+#pragma pack(1)
+
+typedef struct {
+  /*! Local DDR memory size in Bytes */
[SAMI] The doxygen comment stype to be used should be /** instead of /*!. 
Alternatively, you could also follow https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/appendix_a_common_examples#type-declarations 
[/SAMI]

+  UINT64   LocalDdrSize;
+  /*! Remote DDR memory size in Bytes */
+  UINT64   RemoteDdrSize;
+  /*! Slave count in C2C mode */
+  UINT8   SlaveCount;
+  /*! 0 - Single Chip, 1 - Chip to Chip (C2C) */
+  UINT8   Mode;
+} MORELLO_PLAT_INFO;
+
+#pragma pack()
+
+#endif
diff --git a/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.c b/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.c
new file mode 100644
index 000000000000..cd06ca5ce53f
--- /dev/null
+++ b/Platform/ARM/Morello/Library/PlatformLib/PlatformLib.c
@@ -0,0 +1,66 @@
+/** @file
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/ArmPlatformLib.h>
+#include <Library/BaseLib.h>
+#include <Ppi/ArmMpCoreInfo.h>
+
+STATIC ARM_CORE_INFO mCoreInfoTable[] = {
+  { 0x0, 0x0 }, // Cluster 0, Core 0
+  { 0x0, 0x1 }, // Cluster 0, Core 1
+  { 0x1, 0x0 }, // Cluster 1, Core 0
+  { 0x1, 0x1 }  // Cluster 1, Core 1
+};
+
+EFI_BOOT_MODE
+ArmPlatformGetBootMode (
+  VOID
+  )
[SAMI] Please add doxygen function documentation header. Same at other places in this patch series.
[/SAMI]
+{
+  return BOOT_WITH_FULL_CONFIGURATION;
+}
+
+RETURN_STATUS
+ArmPlatformInitialize (
+  IN  UINTN                     MpId
+  )
+{
+  return RETURN_SUCCESS;
+}
+
+EFI_STATUS
+PrePeiCoreGetMpCoreInfo (
+  OUT UINTN                   *CoreCount,
+  OUT ARM_CORE_INFO           **ArmCoreTable
+  )
+{
+  *CoreCount = sizeof (mCoreInfoTable) / sizeof (ARM_CORE_INFO);
+  *ArmCoreTable = mCoreInfoTable;
+  return EFI_SUCCESS;
+}
+
+STATIC ARM_MP_CORE_INFO_PPI mMpCoreInfoPpi = {
+  PrePeiCoreGetMpCoreInfo
+};
+
+STATIC EFI_PEI_PPI_DESCRIPTOR gPlatformPpiTable[] = {
+  {
+    EFI_PEI_PPI_DESCRIPTOR_PPI,
+    &gArmMpCoreInfoPpiGuid,
+    &mMpCoreInfoPpi
+  }
+};
+
+VOID
+ArmPlatformGetPlatformPpiList (
+  OUT UINTN                   *PpiListSize,
+  OUT EFI_PEI_PPI_DESCRIPTOR  **PpiList
+  )
+{
+  *PpiListSize = sizeof (gPlatformPpiTable);
+  *PpiList = gPlatformPpiTable;
+}
diff --git a/Platform/ARM/Morello/Library/PlatformLib/PlatformLibMem.c b/Platform/ARM/Morello/Library/PlatformLib/PlatformLibMem.c
new file mode 100644
index 000000000000..140a6ec79bd3
--- /dev/null
+++ b/Platform/ARM/Morello/Library/PlatformLib/PlatformLibMem.c
@@ -0,0 +1,194 @@
+/** @file
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Library/ArmPlatformLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HobLib.h>
+#include <Library/MemoryAllocationLib.h>
+#include <MorelloPlatform.h>
+
+// The total number of descriptors, including the final "end-of-table" descriptor.
+#define MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS  12
+
+#if !defined(MDEPKG_NDEBUG)
+STATIC CONST CHAR8 *tblAttrDesc[] = {
+  "UNCACHED_UNBUFFERED          ",
+  "NONSECURE_UNCACHED_UNBUFFERED",
+  "WRITE_BACK                   ",
+  "NONSECURE_WRITE_BACK         ",
+  "WB_NONSHAREABLE              ",
+  "NONSECURE_WB_NONSHAREABLE    ",
+  "WRITE_THROUGH                ",
+  "NONSECURE_WRITE_THROUGH      ",
+  "DEVICE                       ",
+  "NONSECURE_DEVICE             "
+};
+#endif
+
+#define LOG_MEM(desc) DEBUG ((                                            \
+                        EFI_D_ERROR,                                      \
[SAMI] Replace EFI_D_ERROR with DEBUG_ERROR at all places in this patch series.
[/SAMI]
+                        desc,                                             \
+                        VirtualMemoryTable[Index].PhysicalBase,           \
+                        (VirtualMemoryTable[Index].PhysicalBase +         \
+                         VirtualMemoryTable[Index].Length - 1),           \
+                        VirtualMemoryTable[Index].Length,                 \
+                        tblAttrDesc[VirtualMemoryTable[Index].Attributes] \
+                        ));
+
+/**
+  Returns the Virtual Memory Map of the platform.
+
+  This Virtual Memory Map is used by MemoryInitPei Module to initialize the MMU
+  on your platform.
+
+  @param[out] VirtualMemoryMap Array of ARM_MEMORY_REGION_DESCRIPTOR describing
+                               a Physical-to-Virtual Memory mapping. This array
+                               must be ended by a zero-filled entry.
+**/
+VOID
+ArmPlatformGetVirtualMemoryMap (
+  IN ARM_MEMORY_REGION_DESCRIPTOR** VirtualMemoryMap
+  )
+{
+  UINTN                           Index = 0;
+  ARM_MEMORY_REGION_DESCRIPTOR  * VirtualMemoryTable;
+  EFI_RESOURCE_ATTRIBUTE_TYPE     ResourceAttributes;
+  MORELLO_PLAT_INFO             * PlatInfo;
+  UINT64                          DramBlock2Size = 0;
+
+  PlatInfo = (MORELLO_PLAT_INFO *)MORELLO_PLAT_INFO_STRUCT_BASE;
+  if (PlatInfo->LocalDdrSize > MORELLO_DRAM_BLOCK1_SIZE)
[SAMI] Add { } braces, see https://edk2-docs.gitbook.io/edk-ii-c-coding-standards-specification/5_source_files/57_c_programming#5-7-3-4-1-the-if-statement-shall-be-followed-by-a-space-and-then-the-open-parenthesis
+    DramBlock2Size = PlatInfo->LocalDdrSize - MORELLO_DRAM_BLOCK1_SIZE;
+
+  if (DramBlock2Size != 0) {
+    ResourceAttributes =
+      EFI_RESOURCE_ATTRIBUTE_PRESENT |
+      EFI_RESOURCE_ATTRIBUTE_INITIALIZED |
+      EFI_RESOURCE_ATTRIBUTE_WRITE_COMBINEABLE |
+      EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
+      EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE |
+      EFI_RESOURCE_ATTRIBUTE_TESTED;
+
+    BuildResourceDescriptorHob (
+      EFI_RESOURCE_SYSTEM_MEMORY,
+      ResourceAttributes,
+      FixedPcdGet64 (PcdDramBlock2Base),
+      DramBlock2Size);
+  }
+
+  ASSERT (VirtualMemoryMap != NULL);
+  Index = 0;
[SAMI] Redundant.
[/SAMI]
+
+  VirtualMemoryTable = AllocatePool (sizeof (ARM_MEMORY_REGION_DESCRIPTOR) *
+                                     MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS);
+  if (VirtualMemoryTable == NULL) {
+    return;
+  }
+
+  DEBUG ((
+    EFI_D_ERROR,
+    " Memory Map\n----------------------------------------------------------\n"
+    ));
+  DEBUG ((
+    EFI_D_ERROR,
+    "Description                     :        START       -        END         " \
+    "[        SIZE        ] {              ATTR             }\n"
+    ));
+
+  // SubSystem Peripherals - Generic Watchdog
+  VirtualMemoryTable[Index].PhysicalBase    = MORELLO_GENERIC_WDOG_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_GENERIC_WDOG_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_GENERIC_WDOG_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("Generic Watchdog                : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // SubSystem Peripherals - GIC-600
+  VirtualMemoryTable[++Index].PhysicalBase  = MORELLO_GIC_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_GIC_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_GIC_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("GIC-600                         : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // SubSystem Peripherals - GICR-600
+  VirtualMemoryTable[++Index].PhysicalBase  = MORELLO_GICR_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_GICR_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_GICR_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("GICR-600                        : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // SubSystem non-secure SRAM
+  VirtualMemoryTable[++Index].PhysicalBase  = MORELLO_NON_SECURE_SRAM_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_NON_SECURE_SRAM_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_NON_SECURE_SRAM_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_UNCACHED_UNBUFFERED;
+  LOG_MEM ("non-secure SRAM                 : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // SubSystem Pheripherals - UART0
+  VirtualMemoryTable[++Index].PhysicalBase  = MORELLO_UART0_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_UART0_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_UART0_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("UART0                           : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // DDR Primary
+  VirtualMemoryTable[++Index].PhysicalBase  = PcdGet64 (PcdSystemMemoryBase);
+  VirtualMemoryTable[Index].VirtualBase     = PcdGet64 (PcdSystemMemoryBase);
+  VirtualMemoryTable[Index].Length          = PcdGet64 (PcdSystemMemorySize);
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+  LOG_MEM ("DDR Primary                     : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // DDR Secondary
+  if (DramBlock2Size != 0) {
+    VirtualMemoryTable[++Index].PhysicalBase  = PcdGet64 (PcdDramBlock2Base);
+    VirtualMemoryTable[Index].VirtualBase     = PcdGet64 (PcdDramBlock2Base);
+    VirtualMemoryTable[Index].Length          = DramBlock2Size;
+    VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_WRITE_BACK;
+    LOG_MEM ("DDR Secondary                   : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+  }
+
+  // Expansion Peripherals
+  VirtualMemoryTable[++Index].PhysicalBase  = MORELLO_EXP_PERIPH_BASE;
+  VirtualMemoryTable[Index].VirtualBase     = MORELLO_EXP_PERIPH_BASE;
+  VirtualMemoryTable[Index].Length          = MORELLO_EXP_PERIPH_BASE_SZ;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("Expansion Peripherals           : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // PCI Configuration Space
+  VirtualMemoryTable[++Index].PhysicalBase  = PcdGet64 (PcdPciExpressBaseAddress);
+  VirtualMemoryTable[Index].VirtualBase     = PcdGet64 (PcdPciExpressBaseAddress);
+  VirtualMemoryTable[Index].Length          = (FixedPcdGet32 (PcdPciBusMax) -
+                                               FixedPcdGet32 (PcdPciBusMin) + 1) *
+                                               SIZE_1MB;
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("PCI Configuration Space         : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // PCI MMIO32/IO Space
+  VirtualMemoryTable[++Index].PhysicalBase  = PcdGet32 (PcdPciMmio32Base);
+  VirtualMemoryTable[Index].VirtualBase     = PcdGet32 (PcdPciMmio32Base);
+  VirtualMemoryTable[Index].Length          = PcdGet32 (PcdPciMmio32Size) +
+                                              PcdGet32 (PcdPciIoSize);
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("PCI MMIO32 & IO Region          : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // PCI MMIO64 Space
+  VirtualMemoryTable[++Index].PhysicalBase  = PcdGet64 (PcdPciMmio64Base);
+  VirtualMemoryTable[Index].VirtualBase     = PcdGet64 (PcdPciMmio64Base);
+  VirtualMemoryTable[Index].Length          = PcdGet64 (PcdPciMmio64Size);
+  VirtualMemoryTable[Index].Attributes      = ARM_MEMORY_REGION_ATTRIBUTE_DEVICE;
+  LOG_MEM ("PCI MMIO64 Region               : 0x%016lx - 0x%016lx [ 0x%016lx ] { %a }\n");
+
+  // End of Table
+  VirtualMemoryTable[++Index].PhysicalBase  = 0;
+  VirtualMemoryTable[Index].VirtualBase     = 0;
+  VirtualMemoryTable[Index].Length          = 0;
+  VirtualMemoryTable[Index].Attributes      = (ARM_MEMORY_REGION_ATTRIBUTES)0;
+
+  ASSERT ((Index) < MAX_VIRTUAL_MEMORY_MAP_DESCRIPTORS);
+  DEBUG ((DEBUG_INIT, "Virtual Memory Table setup complete.\n"));
+
+  *VirtualMemoryMap = VirtualMemoryTable;
+}
diff --git a/Platform/ARM/Morello/Library/PlatformLib/AArch64/Helper.S b/Platform/ARM/Morello/Library/PlatformLib/AArch64/Helper.S
new file mode 100644
index 000000000000..f6cc087a132c
--- /dev/null
+++ b/Platform/ARM/Morello/Library/PlatformLib/AArch64/Helper.S
@@ -0,0 +1,83 @@
+/** @file
+
+  Copyright (c) 2021, ARM Limited. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <AsmMacroIoLibV8.h>
+#include <Library/ArmLib.h>
+
+.text
+.align 3
+
+GCC_ASM_EXPORT(ArmPlatformPeiBootAction)
+GCC_ASM_EXPORT(ArmPlatformGetCorePosition)
+GCC_ASM_EXPORT(ArmPlatformGetPrimaryCoreMpId)
+GCC_ASM_EXPORT(ArmPlatformIsPrimaryCore)
+
+//
+// First platform specific function to be called in the PEI phase
+//
+// This function is actually the first function called by the PrePi
+// or PrePeiCore modules. It allows to retrieve arguments passed to
+// the UEFI firmware through the CPU registers.
+//
+ASM_PFX(ArmPlatformPeiBootAction):
+  ret
+
+//
+// Return the core position from the value of its MpId register
+//
+// This function returns core position from the position 0 in the processor.
+// This function might be called from assembler before any stack is set.
+//
+// @return   Return the core position
+//
+//UINTN
+//ArmPlatformGetCorePosition (
+//  IN UINTN MpId
+//  );
+// With this function: CorePos = (ClusterId * 2) + CoreId
+ASM_PFX(ArmPlatformGetCorePosition):
+  and   x1, x0, #ARM_CORE_MASK
+  and   x0, x0, #ARM_CLUSTER_MASK
+  add   x0, x1, x0, LSR #7
+  ret
+
+//
+// Return the MpId of the primary core
+//
+// This function returns the MpId of the primary core.
+// This function might be called from assembler before any stack is set.
+//
+// @return   Return the MpId of the primary core
+//
+//UINTN
+//ArmPlatformGetPrimaryCoreMpId (
+//  VOID
+//  );
+ASM_PFX(ArmPlatformGetPrimaryCoreMpId):
+  MOV32 (w0, FixedPcdGet32(PcdArmPrimaryCore))
+  ret
+
+//
+// Return a non-zero value if the callee is the primary core
+//
+// This function returns a non-zero value if the callee is the primary core.
+// Primary core is the core responsible to initialize hardware and run UEFI.
+// This function might be called from assembler before any stack is set.
+//
+//  @return   Return a non-zero value if the callee is the primary core.
+//
+//UINTN
+//ArmPlatformIsPrimaryCore (
+//  IN UINTN MpId
+//  );
+ASM_PFX(ArmPlatformIsPrimaryCore):
+  MOV32 (w1, FixedPcdGet32(PcdArmPrimaryCoreMask))
+  and   x0, x0, x1
+  MOV32 (w1, FixedPcdGet32(PcdArmPrimaryCore))
+  cmp   w0, w1
+  cset  x0, eq
+  ret
-- 
2.17.1