OvmfPkg/PlatformPei: stop using cmos for memory detection

Not needed for qemu 1.7 (released in 2013) and newer.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3593
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 4 insertions, 55 deletions

diff --git a/OvmfPkg/PlatformPei/MemDetect.c b/OvmfPkg/PlatformPei/MemDetect.c
index 1bcb5a08bc..fb38e3c39d 100644
--- a/OvmfPkg/PlatformPei/MemDetect.c
+++ b/OvmfPkg/PlatformPei/MemDetect.c
@@ -38,7 +38,6 @@ Module Name:
 #include <Library/QemuFwCfgSimpleParserLib.h>

 

 #include "Platform.h"

-#include "Cmos.h"

 

 UINT8  mPhysMemAddressWidth;

 

@@ -322,51 +321,11 @@ GetSystemMemorySizeBelow4gb (
 {

   EFI_STATUS  Status;

   UINT64      LowerMemorySize = 0;

-  UINT8       Cmos0x34;

-  UINT8       Cmos0x35;

 

   Status = ScanOrAdd64BitE820Ram (FALSE, &LowerMemorySize, NULL);

-  if ((Status == EFI_SUCCESS) && (LowerMemorySize > 0)) {

-    return (UINT32)LowerMemorySize;

-  }

-

-  //

-  // CMOS 0x34/0x35 specifies the system memory above 16 MB.

-  // * CMOS(0x35) is the high byte

-  // * CMOS(0x34) is the low byte

-  // * The size is specified in 64kb chunks

-  // * Since this is memory above 16MB, the 16MB must be added

-  //   into the calculation to get the total memory size.

-  //

-

-  Cmos0x34 = (UINT8)CmosRead8 (0x34);

-  Cmos0x35 = (UINT8)CmosRead8 (0x35);

-

-  return (UINT32)(((UINTN)((Cmos0x35 << 8) + Cmos0x34) << 16) + SIZE_16MB);

-}

-

-STATIC

-UINT64

-GetSystemMemorySizeAbove4gb (

-  )

-{

-  UINT32  Size;

-  UINTN   CmosIndex;

-

-  //

-  // CMOS 0x5b-0x5d specifies the system memory above 4GB MB.

-  // * CMOS(0x5d) is the most significant size byte

-  // * CMOS(0x5c) is the middle size byte

-  // * CMOS(0x5b) is the least significant size byte

-  // * The size is specified in 64kb chunks

-  //

-

-  Size = 0;

-  for (CmosIndex = 0x5d; CmosIndex >= 0x5b; CmosIndex--) {

-    Size = (UINT32)(Size << 8) + (UINT32)CmosRead8 (CmosIndex);

-  }

-

-  return LShiftU64 (Size, 16);

+  ASSERT_EFI_ERROR (Status);

+  ASSERT (LowerMemorySize > 0);

+  return (UINT32)LowerMemorySize;

 }

 

 /**

@@ -396,12 +355,9 @@ GetFirstNonAddress (
   // If QEMU presents an E820 map, then get the highest exclusive >=4GB RAM

   // address from it. This can express an address >= 4GB+1TB.

   //

-  // Otherwise, get the flat size of the memory above 4GB from the CMOS (which

-  // can only express a size smaller than 1TB), and add it to 4GB.

-  //

   Status = ScanOrAdd64BitE820Ram (FALSE, NULL, &FirstNonAddress);

   if (EFI_ERROR (Status)) {

-    FirstNonAddress = BASE_4GB + GetSystemMemorySizeAbove4gb ();

+    FirstNonAddress = BASE_4GB;

   }

 

   //

@@ -773,7 +729,6 @@ QemuInitializeRam (
   )

 {

   UINT64         LowerMemorySize;

-  UINT64         UpperMemorySize;

   MTRR_SETTINGS  MtrrSettings;

   EFI_STATUS     Status;

 

@@ -832,12 +787,6 @@ QemuInitializeRam (
     // memory size read from the CMOS.

     //

     Status = ScanOrAdd64BitE820Ram (TRUE, NULL, NULL);

-    if (EFI_ERROR (Status)) {

-      UpperMemorySize = GetSystemMemorySizeAbove4gb ();

-      if (UpperMemorySize != 0) {

-        AddMemoryBaseSizeHob (BASE_4GB, UpperMemorySize);

-      }

-    }

   }

 

   //