edk2: QcomModulePkg: Calculate image offsets based on Header Version

[Cherry-picked from
https://source.codeaurora.org/quic/la/abl/tianocore/edk2/commit/?id=221dc1de0c97e4eb91262e67539908fb0b0f14e3

]

When we disable avb feature, calculate the size of the data needed to be
read from the flash completely. Add suport to read the dtb.img
which is present at the end of the boot image in case of the header
version 2. This change is needed because up until header version 2, dtbs
were appended to the kernel and in kernel size, dtbs were included.

Change-Id: Iad055672e473951fc92c4138c98555e67875aeb0
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>

QcomModulePkg/Library/BootLib/BootLinux.c

@@ -1309,6 +1309,7 @@ CheckImageHeader (VOID *ImageHdrBuffer,
                   BOOLEAN BootIntoRecovery)
 {
   EFI_STATUS Status = EFI_SUCCESS;
+  struct boot_img_hdr_v2 *BootImgHdrV2;
   UINT32 KernelSizeActual = 0;
   UINT32 DtSizeActual = 0;
   UINT32 RamdiskSizeActual = 0;
@@ -1318,6 +1319,7 @@ CheckImageHeader (VOID *ImageHdrBuffer,
   UINT32 KernelSize = 0;
   UINT32 RamdiskSize = 0;
   UINT32 SecondSize = 0;
+  UINT32 DtSize = 0;
   UINT32 tempImgSize = 0;
 
   if (CompareMem ((void *)((boot_img_hdr *)(ImageHdrBuffer))->magic, BOOT_MAGIC,
@@ -1358,6 +1360,21 @@ CheckImageHeader (VOID *ImageHdrBuffer,
     return EFI_BAD_BUFFER_SIZE;
   }
 
+  if (HeaderVersion == BOOT_HEADER_VERSION_TWO) {
+    BootImgHdrV2 = (struct boot_img_hdr_v2 *)
+        ((UINT64) ImageHdrBuffer +
+        BOOT_IMAGE_HEADER_V1_RECOVERY_DTBO_SIZE_OFFSET +
+        BOOT_IMAGE_HEADER_V2_OFFSET);
+    DtSize = BootImgHdrV2->dtb_size;
+
+    DtSizeActual = ROUND_TO_PAGE (DtSize, *PageSize - 1);
+    if (DtSize &&
+        !DtSizeActual) {
+      DEBUG ((EFI_D_ERROR, "Integer Overflow: dt Size = %u\n", DtSize));
+      return EFI_BAD_BUFFER_SIZE;
+    }
+  }
+
   *ImageSizeActual = ADD_OF (*PageSize, KernelSizeActual);
   if (!*ImageSizeActual) {
     DEBUG ((EFI_D_ERROR, "Integer Overflow: Actual Kernel size = %u\n",