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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>
This commit is contained in:
Gerd Hoffmann 2021-12-08 08:01:46 +01:00 committed by mergify[bot]
parent 759e3c6d21
commit 41d8bb3038
1 changed files with 4 additions and 55 deletions
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59
OvmfPkg/PlatformPei/MemDetect.c
View File

@ -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);
}
}
}
//