[PATCH 2/5] OvmfPkg/AcpiPlatformDxe: add QEMU_LOADER_WRITE_POINTER definitions

[Laszlo Ersek <lersek@redhat.com>]

Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=359
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
---
 OvmfPkg/AcpiPlatformDxe/QemuLoader.h | 26 ++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/OvmfPkg/AcpiPlatformDxe/QemuLoader.h b/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
index b29944378d76..437776d86d9a 100644
--- a/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
+++ b/OvmfPkg/AcpiPlatformDxe/QemuLoader.h
@@ -26,10 +26,11 @@
 
 typedef enum {
   QemuLoaderCmdAllocate = 1,
   QemuLoaderCmdAddPointer,
   QemuLoaderCmdAddChecksum,
+  QemuLoaderCmdWritePointer,
 } QEMU_LOADER_COMMAND_TYPE;
 
 typedef enum {
   QemuLoaderAllocHigh = 1,
   QemuLoaderAllocFSeg
@@ -70,16 +71,41 @@ typedef struct {
   UINT32 ResultOffset;
   UINT32 Start;
   UINT32 Length;
 } QEMU_LOADER_ADD_CHECKSUM;
 
+//
+// QemuLoaderCmdWritePointer: the bytes at
+// [PointerOffset..PointerOffset+PointerSize) in the writeable fw_cfg file
+// PointerFile are to receive the absolute address of PointeeFile, as allocated
+// and downloaded by the firmware, incremented by the value of PointeeOffset.
+// Store the sum of (a) the base address of where PointeeFile's contents have
+// been placed (when QemuLoaderCmdAllocate has been executed for PointeeFile)
+// and (b) PointeeOffset, to this portion of PointerFile.
+//
+// This command is similar to QemuLoaderCmdAddPointer; the difference is that
+// the "pointer to patch" does not exist in guest-physical address space, only
+// in "fw_cfg file space". In addition, the "pointer to patch" is not
+// initialized by QEMU in-place with a possibly nonzero offset value: the
+// relative offset into PointeeFile comes from the explicit PointeeOffset
+// field.
+//
+typedef struct {
+  UINT8  PointerFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+  UINT8  PointeeFile[QEMU_LOADER_FNAME_SIZE]; // NUL-terminated
+  UINT32 PointerOffset;
+  UINT32 PointeeOffset;
+  UINT8  PointerSize;                         // one of 1, 2, 4, 8
+} QEMU_LOADER_WRITE_POINTER;
+
 typedef struct {
   UINT32 Type;                             // QEMU_LOADER_COMMAND_TYPE values
   union {
     QEMU_LOADER_ALLOCATE      Allocate;
     QEMU_LOADER_ADD_POINTER   AddPointer;
     QEMU_LOADER_ADD_CHECKSUM  AddChecksum;
+    QEMU_LOADER_WRITE_POINTER WritePointer;
     UINT8                     Padding[124];
   } Command;
 } QEMU_LOADER_ENTRY;
 #pragma pack ()
 
-- 
2.9.3