EmbeddedPkg/PrePiLib: Add FFS_CHECK_SECTION_HOOK when finding section

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>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>

EmbeddedPkg/Include/Library/PrePiLib.h

@@ -53,10 +53,22 @@ FfsFindNextFile (
   );
 
 /**
-  This service enables discovery sections of a given type within a valid FFS file.
+ * 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
+  );
 
-  @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
+  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  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.
 
@@ -68,6 +80,7 @@ EFI_STATUS
 EFIAPI
 FfsFindSectionData (
   IN EFI_SECTION_TYPE        SectionType,
+  IN FFS_CHECK_SECTION_HOOK  SectionCheckHook,
   IN EFI_PEI_FILE_HANDLE     FileHandle,
   OUT VOID                   **SectionData
   );

EmbeddedPkg/Library/PrePiLib/FwVol.c

@@ -265,6 +265,7 @@ FindFileEx (
   when meeting an encapsuled section.
 
   @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.
@@ -274,6 +275,7 @@ FindFileEx (
 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;
@@ -302,6 +306,13 @@ FfsProcessSection (
     }
 
     if (Section->Type == SectionType) {
+      if (SectionCheckHook != NULL) {
+        Found = SectionCheckHook (Section) == EFI_SUCCESS;
+      } else {
+        Found = TRUE;
+      }
+
+      if (Found) {
         if (IS_SECTION2 (Section)) {
           *OutputBuffer = (VOID *)((UINT8 *)Section + sizeof (EFI_COMMON_SECTION_HEADER2));
         } else {
@@ -309,6 +320,9 @@ FfsProcessSection (
         }
 
         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 {
@@ -457,6 +473,7 @@ EFI_STATUS
 EFIAPI
 FfsFindSectionData (
   IN EFI_SECTION_TYPE        SectionType,
+  IN FFS_CHECK_SECTION_HOOK  SectionCheckHook,
   IN EFI_PEI_FILE_HANDLE     FileHandle,
   OUT VOID                   **SectionData
   )
@@ -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;
   }

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;
   }