OvmfPkg/AcpiPlatformDxe: update PointerValue comments in "BootScript.c"

Commit df73df138d9d ("OvmfPkg/AcpiPlatformDxe: replay
QEMU_LOADER_WRITE_POINTER commands at S3", 2017-02-09) added
"BootScript.c" with such comments on the PointerValue field of
CONDENSED_WRITE_POINTER, and on the corresponding PointerValue parameter
of SaveCondensedWritePointerToS3Context(), that did not consider the
then-latest update of the QEMU_LOADER_WRITE_POINTER structure. (Namely,
the introduction of the PointeeOffset field.)

The code is fine as-is -- ProcessCmdWritePointer() already calls
SaveCondensedWritePointerToS3Context() correctly, and "BootScript.c"
itself is indifferent to the exact values --, but the comments in
"BootScript.c" should match reality too. Update them.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/OvmfPkg/AcpiPlatformDxe/BootScript.c b/OvmfPkg/AcpiPlatformDxe/BootScript.c
index b7a7f27..1ad468e 100644
--- a/OvmfPkg/AcpiPlatformDxe/BootScript.c
+++ b/OvmfPkg/AcpiPlatformDxe/BootScript.c
@@ -29,6 +29,7 @@ typedef struct {
   UINT8  PointerSize;   // copied as-is from QEMU_LOADER_WRITE_POINTER

   UINT32 PointerOffset; // copied as-is from QEMU_LOADER_WRITE_POINTER

   UINT64 PointerValue;  // resolved from QEMU_LOADER_WRITE_POINTER.PointeeFile

+                        //   and QEMU_LOADER_WRITE_POINTER.PointeeOffset

 } CONDENSED_WRITE_POINTER;

 

 

@@ -159,7 +160,8 @@ ReleaseS3Context (
 

   @param[in] PointerValue   The base address of the allocated / downloaded

                             fw_cfg blob that is identified by

-                            QEMU_LOADER_WRITE_POINTER.PointeeFile.

+                            QEMU_LOADER_WRITE_POINTER.PointeeFile, plus

+                            QEMU_LOADER_WRITE_POINTER.PointeeOffset.

 

   @retval EFI_SUCCESS           The information derived from

                                 QEMU_LOADER_WRITE_POINTER has been successfully

@@ -271,9 +273,9 @@ TransferS3ContextToBootScript (
   // (2) call QEMU with the FW_CFG_DMA_ACCESS object,

   // (3) wait for the select+skip to finish,

   // (4) restore a SCRATCH_BUFFER object in reserved memory that writes

-  //     PointerValue (base address of the allocated / downloaded PointeeFile),

-  //     of size PointerSize, into the fw_cfg file selected in (1), at the

-  //     offset sought to in (1),

+  //     PointerValue (base address of the allocated / downloaded PointeeFile,

+  //     plus PointeeOffset), of size PointerSize, into the fw_cfg file

+  //     selected in (1), at the offset sought to in (1),

   // (5) call QEMU with the FW_CFG_DMA_ACCESS object,

   // (6) wait for the write to finish.

   //

@@ -346,8 +348,8 @@ TransferS3ContextToBootScript (
     //

     // (4) restore a SCRATCH_BUFFER object in reserved memory that writes

     //     PointerValue (base address of the allocated / downloaded

-    //     PointeeFile), of size PointerSize, into the fw_cfg file selected in

-    //     (1), at the offset sought to in (1),

+    //     PointeeFile, plus PointeeOffset), of size PointerSize, into the

+    //     fw_cfg file selected in (1), at the offset sought to in (1),

     //

     Access->Control = SwapBytes32 (FW_CFG_DMA_CTL_WRITE);

     Access->Length = SwapBytes32 (Condensed->PointerSize);