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|
;; @file
; Code template of the SMI handler for a particular processor
;
; Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR>
;
; This program and the accompanying materials
; are licensed and made available under the terms and conditions of the BSD License
; which accompanies this distribution. The full text of the license may be found at
; http://opensource.org/licenses/bsd-license.php.
;
; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;
;;
.686p
.model flat,C
.xmm
DSC_OFFSET EQU 0fb00h
DSC_GDTPTR EQU 30h
DSC_GDTSIZ EQU 38h
DSC_CS EQU 14
DSC_DS EQU 16
DSC_SS EQU 18
DSC_OTHERSEG EQU 20
MSR_DR6 EQU 0c05h
MSR_DR7 EQU 0c06h
TSS_SEGMENT EQU 40h
SmiRendezvous PROTO C
EXTERNDEF gcSmiHandlerTemplate:BYTE
EXTERNDEF gcSmiHandlerSize:WORD
EXTERNDEF gSmiCr3:DWORD
EXTERNDEF gcSmiHandlerOffset:WORD
EXTERNDEF gSmiStack:DWORD
EXTERNDEF gSmbase:DWORD
EXTERNDEF FeaturePcdGet (PcdCpuSmmDebug):BYTE
EXTERNDEF FeaturePcdGet (PcdCpuSmmStackGuard):BYTE
.const
gcSmiHandlerOffset DW _SmiHandler - _SmiEntryPoint + 8000h
.code
gcSmiHandlerTemplate LABEL BYTE
_SmiEntryPoint PROC
DB 0bbh ; mov bx, imm16
DW offset _GdtDesc - _SmiEntryPoint + 8000h
DB 2eh, 0a1h ; mov ax, cs:[offset16]
DW DSC_OFFSET + DSC_GDTSIZ
dec eax
mov cs:[edi], eax ; mov cs:[bx], ax
DB 66h, 2eh, 0a1h ; mov eax, cs:[offset16]
DW DSC_OFFSET + DSC_GDTPTR
mov cs:[edi + 2], ax ; mov cs:[bx + 2], eax
mov bp, ax ; ebp = GDT base
DB 66h
lgdt fword ptr cs:[edi] ; lgdt fword ptr cs:[bx]
DB 66h, 0b8h ; mov eax, imm32
gSmiCr3 DD ?
mov cr3, eax
DB 66h
mov eax, 668h ; as cr4.PGE is not set here, refresh cr3
mov cr4, eax ; in PreModifyMtrrs() to flush TLB.
DB 2eh, 0a1h ; mov ax, cs:[offset16]
DW DSC_OFFSET + DSC_CS
mov cs:[edi - 2], eax ; mov cs:[bx - 2], ax
DB 66h, 0bfh ; mov edi, SMBASE
gSmbase DD ?
DB 67h
lea ax, [edi + (@32bit - _SmiEntryPoint) + 8000h]
mov cs:[edi - 6], ax ; mov cs:[bx - 6], eax
mov ebx, cr0
DB 66h
and ebx, 9ffafff3h
DB 66h
or ebx, 80000023h
mov cr0, ebx
DB 66h, 0eah
DD ?
DW ?
_GdtDesc FWORD ?
@32bit:
lea ebx, [edi + DSC_OFFSET]
mov ax, [ebx + DSC_DS]
mov ds, eax
mov ax, [ebx + DSC_OTHERSEG]
mov es, eax
mov fs, eax
mov gs, eax
mov ax, [ebx + DSC_SS]
mov ss, eax
cmp FeaturePcdGet (PcdCpuSmmStackGuard), 0
jz @F
; Load TSS
mov byte ptr [ebp + TSS_SEGMENT + 5], 89h ; clear busy flag
mov eax, TSS_SEGMENT
ltr ax
@@:
; jmp _SmiHandler ; instruction is not needed
_SmiEntryPoint ENDP
_SmiHandler PROC
DB 0bch ; mov esp, imm32
gSmiStack DD ?
cmp FeaturePcdGet (PcdCpuSmmDebug), 0
jz @3
jz @F
@@:
call @1
@1:
pop ebp
mov eax, 80000001h
cpuid
bt edx, 29 ; check cpuid to identify X64 or IA32
lea edi, [ebp - (@1 - _SmiEntryPoint) + 7fc8h]
lea esi, [edi + 4]
jnc @2
add esi, 4
@2:
mov ecx, [esi]
mov edx, [edi]
@5:
mov dr6, ecx
mov dr7, edx ; restore DR6 & DR7 before running C code
@3:
mov ecx, [esp] ; CPU Index
push ecx
mov eax, SmiRendezvous
call eax
pop ecx
cmp FeaturePcdGet (PcdCpuSmmDebug), 0
jz @4
mov ecx, dr6
mov edx, dr7
mov [esi], ecx
mov [edi], edx
@4:
rsm
_SmiHandler ENDP
gcSmiHandlerSize DW $ - _SmiEntryPoint
END
|
