[PATCH V3 1/4] EmbeddedPkg/PrePiLib: Add FFS_CHECK_SECTION_HOOK when finding section

["Min Xu" <min.m.xu@intel.com>]

From: Min M Xu <min.m.xu@intel.com>

BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=4152

EmbeddedPkg/PrePiLib provides the service of finding sections based on
the input SectionType. But sometimes there maybe multiple sections
with the same SectionType. FFS_CHECK_SECTION_HOOK is a hook which can
be called to do additional check.

Cc: Leif Lindholm <quic_llindhol@quicinc.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Abner Chang <abner.chang@amd.com>
Cc: Daniel Schaefer <git@danielschaefer.me>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Ard Biesheuvel <ardb+tianocore@kernel.org>
Signed-off-by: Min Xu <min.m.xu@intel.com>
---
 EmbeddedPkg/Include/Library/PrePiLib.h  | 23 +++++++++++---
 EmbeddedPkg/Library/PrePiLib/FwVol.c    | 42 ++++++++++++++++++-------
 EmbeddedPkg/Library/PrePiLib/PrePiLib.c |  2 +-
 3 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/EmbeddedPkg/Include/Library/PrePiLib.h b/EmbeddedPkg/Include/Library/PrePiLib.h
index 3741b08c4478..f60b6678185a 100644
--- a/EmbeddedPkg/Include/Library/PrePiLib.h
+++ b/EmbeddedPkg/Include/Library/PrePiLib.h
@@ -52,11 +52,23 @@ FfsFindNextFile (
   IN OUT EFI_PEI_FILE_HANDLE  *FileHandle
   );
 
+/**
+ * This is a hook which is used to check if the section is the target one.
+ *
+ */
+typedef
+EFI_STATUS
+(EFIAPI *FFS_CHECK_SECTION_HOOK)(
+  IN EFI_COMMON_SECTION_HEADER *Section
+  );
+
 /**
   This service enables discovery sections of a given type within a valid FFS file.
+  Caller also can provide a SectionCheckHook to do additional checking.
 
-  @param  SearchType            The value of the section type to find.
-  @param  FfsFileHeader         A pointer to the file header that contains the set of sections to
+  @param  SectionType           The value of the section type to find.
+  @param  SectionCheckHook      A hook which can check if the section is the target one.
+  @param  FileHeader            A pointer to the file header that contains the set of sections to
                                 be searched.
   @param  SectionData           A pointer to the discovered section, if successful.
 
@@ -67,9 +79,10 @@ FfsFindNextFile (
 EFI_STATUS
 EFIAPI
 FfsFindSectionData (
-  IN EFI_SECTION_TYPE     SectionType,
-  IN EFI_PEI_FILE_HANDLE  FileHandle,
-  OUT VOID                **SectionData
+  IN EFI_SECTION_TYPE        SectionType,
+  IN FFS_CHECK_SECTION_HOOK  SectionCheckHook,
+  IN EFI_PEI_FILE_HANDLE     FileHandle,
+  OUT VOID                   **SectionData
   );
 
 /**
diff --git a/EmbeddedPkg/Library/PrePiLib/FwVol.c b/EmbeddedPkg/Library/PrePiLib/FwVol.c
index 0a6d6925b7ea..778d8b13c33b 100644
--- a/EmbeddedPkg/Library/PrePiLib/FwVol.c
+++ b/EmbeddedPkg/Library/PrePiLib/FwVol.c
@@ -264,16 +264,18 @@ FindFileEx (
   Go through the file to search SectionType section,
   when meeting an encapsuled section.
 
-  @param  SectionType  - Filter to find only section of this type.
-  @param  Section      - From where to search.
-  @param  SectionSize  - The file size to search.
-  @param  OutputBuffer - Pointer to the section to search.
+  @param  SectionType       - Filter to find only section of this type.
+  @param  SectionCheckHook  - A hook which can check if the section is the target one.
+  @param  Section           - From where to search.
+  @param  SectionSize       - The file size to search.
+  @param  OutputBuffer      - Pointer to the section to search.
 
   @retval EFI_SUCCESS
 **/
 EFI_STATUS
 FfsProcessSection (
   IN EFI_SECTION_TYPE           SectionType,
+  IN FFS_CHECK_SECTION_HOOK     SectionCheckHook,
   IN EFI_COMMON_SECTION_HEADER  *Section,
   IN UINTN                      SectionSize,
   OUT VOID                      **OutputBuffer
@@ -292,7 +294,9 @@ FfsProcessSection (
   UINT32                    AuthenticationStatus;
   CHAR8                     *CompressedData;
   UINT32                    CompressedDataLength;
+  BOOLEAN                   Found;
 
+  Found         = FALSE;
   *OutputBuffer = NULL;
   ParsedLength  = 0;
   Status        = EFI_NOT_FOUND;
@@ -302,13 +306,23 @@ FfsProcessSection (
     }
 
     if (Section->Type == SectionType) {
-      if (IS_SECTION2 (Section)) {
-        *OutputBuffer = (VOID *)((UINT8 *)Section + sizeof (EFI_COMMON_SECTION_HEADER2));
+      if (SectionCheckHook != NULL) {
+        Found = SectionCheckHook (Section) == EFI_SUCCESS;
       } else {
-        *OutputBuffer = (VOID *)((UINT8 *)Section + sizeof (EFI_COMMON_SECTION_HEADER));
+        Found = TRUE;
       }
 
-      return EFI_SUCCESS;
+      if (Found) {
+        if (IS_SECTION2 (Section)) {
+          *OutputBuffer = (VOID *)((UINT8 *)Section + sizeof (EFI_COMMON_SECTION_HEADER2));
+        } else {
+          *OutputBuffer = (VOID *)((UINT8 *)Section + sizeof (EFI_COMMON_SECTION_HEADER));
+        }
+
+        return EFI_SUCCESS;
+      } else {
+        goto CheckNextSection;
+      }
     } else if ((Section->Type == EFI_SECTION_COMPRESSION) || (Section->Type == EFI_SECTION_GUID_DEFINED)) {
       if (Section->Type == EFI_SECTION_COMPRESSION) {
         if (IS_SECTION2 (Section)) {
@@ -415,6 +429,7 @@ FfsProcessSection (
       } else {
         return FfsProcessSection (
                  SectionType,
+                 SectionCheckHook,
                  DstBuffer,
                  DstBufferSize,
                  OutputBuffer
@@ -422,6 +437,7 @@ FfsProcessSection (
       }
     }
 
+CheckNextSection:
     if (IS_SECTION2 (Section)) {
       SectionLength = SECTION2_SIZE (Section);
     } else {
@@ -456,9 +472,10 @@ FfsProcessSection (
 EFI_STATUS
 EFIAPI
 FfsFindSectionData (
-  IN EFI_SECTION_TYPE     SectionType,
-  IN EFI_PEI_FILE_HANDLE  FileHandle,
-  OUT VOID                **SectionData
+  IN EFI_SECTION_TYPE        SectionType,
+  IN FFS_CHECK_SECTION_HOOK  SectionCheckHook,
+  IN EFI_PEI_FILE_HANDLE     FileHandle,
+  OUT VOID                   **SectionData
   )
 {
   EFI_FFS_FILE_HEADER        *FfsFileHeader;
@@ -478,6 +495,7 @@ FfsFindSectionData (
 
   return FfsProcessSection (
            SectionType,
+           SectionCheckHook,
            Section,
            FileSize,
            SectionData
@@ -799,7 +817,7 @@ FfsProcessFvFile (
   //
   // Find FvImage in FvFile
   //
-  Status = FfsFindSectionData (EFI_SECTION_FIRMWARE_VOLUME_IMAGE, FvFileHandle, (VOID **)&FvImageHandle);
+  Status = FfsFindSectionData (EFI_SECTION_FIRMWARE_VOLUME_IMAGE, NULL, FvFileHandle, (VOID **)&FvImageHandle);
   if (EFI_ERROR (Status)) {
     return Status;
   }
diff --git a/EmbeddedPkg/Library/PrePiLib/PrePiLib.c b/EmbeddedPkg/Library/PrePiLib/PrePiLib.c
index a0c5d02debd0..3b6fc4f0eba8 100644
--- a/EmbeddedPkg/Library/PrePiLib/PrePiLib.c
+++ b/EmbeddedPkg/Library/PrePiLib/PrePiLib.c
@@ -131,7 +131,7 @@ LoadDxeCoreFromFfsFile (
   VOID                  *Hob;
   EFI_FV_FILE_INFO      FvFileInfo;
 
-  Status = FfsFindSectionData (EFI_SECTION_PE32, FileHandle, &PeCoffImage);
+  Status = FfsFindSectionData (EFI_SECTION_PE32, NULL, FileHandle, &PeCoffImage);
   if (EFI_ERROR (Status)) {
     return Status;
   }
-- 
2.29.2.windows.2