diff options
| -rw-r--r-- | UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm index 08534db..9231aa5 100644 --- a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm +++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmmInit.nasm @@ -41,24 +41,21 @@ ASM_PFX(gcSmiInitGdtr): DQ 0
global ASM_PFX(SmmStartup)
+
+BITS 16
ASM_PFX(SmmStartup):
- DB 0x66
mov eax, 0x80000001 ; read capability
cpuid
- DB 0x66
mov ebx, edx ; rdmsr will change edx. keep it in ebx.
DB 0x66, 0xb8 ; mov eax, imm32
ASM_PFX(gSmmCr3): DD 0
mov cr3, eax
- DB 0x67, 0x66
- lgdt [cs:ebp + (ASM_PFX(gcSmiInitGdtr) - ASM_PFX(SmmStartup))]
+o32 lgdt [cs:ebp + (ASM_PFX(gcSmiInitGdtr) - ASM_PFX(SmmStartup))]
DB 0x66, 0xb8 ; mov eax, imm32
ASM_PFX(gSmmCr4): DD 0
mov cr4, eax
- DB 0x66
mov ecx, 0xc0000080 ; IA32_EFER MSR
rdmsr
- DB 0x66
test ebx, BIT20 ; check NXE capability
jz .1
or ah, BIT3 ; set NXE bit
@@ -66,12 +63,14 @@ ASM_PFX(gSmmCr4): DD 0 .1:
DB 0x66, 0xb8 ; mov eax, imm32
ASM_PFX(gSmmCr0): DD 0
- DB 0xbf, PROTECT_MODE_DS, 0 ; mov di, PROTECT_MODE_DS
+ mov di, PROTECT_MODE_DS
mov cr0, eax
DB 0x66, 0xea ; jmp far [ptr48]
ASM_PFX(gSmmJmpAddr):
DD @32bit
DW PROTECT_MODE_CS
+
+BITS 32
@32bit:
mov ds, edi
mov es, edi
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