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|
;------------------------------------------------------------------------------ ;
; Copyright (c) 2009 - 2016, 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.
;
; Module Name:
;
; SmiEntry.asm
;
; Abstract:
;
; Code template of the SMI handler for a particular processor
;
;-------------------------------------------------------------------------------
.686p
.model flat,C
.xmm
MSR_IA32_MISC_ENABLE EQU 1A0h
MSR_EFER EQU 0c0000080h
MSR_EFER_XD EQU 0800h
;
; Constants relating to PROCESSOR_SMM_DESCRIPTOR
;
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
PROTECT_MODE_CS EQU 08h
PROTECT_MODE_DS EQU 20h
TSS_SEGMENT EQU 40h
SmiRendezvous PROTO C
CpuSmmDebugEntry PROTO C
CpuSmmDebugExit PROTO C
EXTERNDEF gcSmiHandlerTemplate:BYTE
EXTERNDEF gcSmiHandlerSize:WORD
EXTERNDEF gSmiCr3:DWORD
EXTERNDEF gSmiStack:DWORD
EXTERNDEF gSmbase:DWORD
EXTERNDEF mXdSupported:BYTE
EXTERNDEF FeaturePcdGet (PcdCpuSmmStackGuard):BYTE
EXTERNDEF gSmiHandlerIdtr:FWORD
.code
gcSmiHandlerTemplate LABEL BYTE
_SmiEntryPoint:
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]
; Patch ProtectedMode Segment
DB 0b8h ; mov ax, imm16
DW PROTECT_MODE_CS ; set AX for segment directly
mov cs:[edi - 2], eax ; mov cs:[bx - 2], ax
; Patch ProtectedMode entry
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, 23h
mov cr0, ebx
DB 66h, 0eah
DD ?
DW ?
_GdtDesc FWORD ?
@32bit:
mov ax, PROTECT_MODE_DS
mov ds, ax
mov es, ax
mov fs, ax
mov gs, ax
mov ss, ax
DB 0bch ; mov esp, imm32
gSmiStack DD ?
mov eax, offset gSmiHandlerIdtr
lidt fword ptr [eax]
jmp ProtFlatMode
ProtFlatMode:
DB 0b8h ; mov eax, imm32
gSmiCr3 DD ?
mov cr3, eax
;
; Need to test for CR4 specific bit support
;
mov eax, 1
cpuid ; use CPUID to determine if specific CR4 bits are supported
xor eax, eax ; Clear EAX
test edx, BIT2 ; Check for DE capabilities
jz @f
or eax, BIT3
@@:
test edx, BIT6 ; Check for PAE capabilities
jz @f
or eax, BIT5
@@:
test edx, BIT7 ; Check for MCE capabilities
jz @f
or eax, BIT6
@@:
test edx, BIT24 ; Check for FXSR capabilities
jz @f
or eax, BIT9
@@:
test edx, BIT25 ; Check for SSE capabilities
jz @f
or eax, BIT10
@@: ; as cr4.PGE is not set here, refresh cr3
mov cr4, eax ; in PreModifyMtrrs() to flush TLB.
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
@@:
; enable NXE if supported
DB 0b0h ; mov al, imm8
mXdSupported DB 1
cmp al, 0
jz @SkipXd
;
; Check XD disable bit
;
mov ecx, MSR_IA32_MISC_ENABLE
rdmsr
push edx ; save MSR_IA32_MISC_ENABLE[63-32]
test edx, BIT2 ; MSR_IA32_MISC_ENABLE[34]
jz @f
and dx, 0FFFBh ; clear XD Disable bit if it is set
wrmsr
@@:
mov ecx, MSR_EFER
rdmsr
or ax, MSR_EFER_XD ; enable NXE
wrmsr
jmp @XdDone
@SkipXd:
sub esp, 4
@XdDone:
mov ebx, cr0
or ebx, 080010023h ; enable paging + WP + NE + MP + PE
mov cr0, ebx
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
; jmp _SmiHandler ; instruction is not needed
_SmiHandler PROC
mov ebx, [esp + 4] ; CPU Index
push ebx
mov eax, CpuSmmDebugEntry
call eax
add esp, 4
push ebx
mov eax, SmiRendezvous
call eax
add esp, 4
push ebx
mov eax, CpuSmmDebugExit
call eax
add esp, 4
mov eax, mXdSupported
mov al, [eax]
cmp al, 0
jz @f
pop edx ; get saved MSR_IA32_MISC_ENABLE[63-32]
test edx, BIT2
jz @f
mov ecx, MSR_IA32_MISC_ENABLE
rdmsr
or dx, BIT2 ; set XD Disable bit if it was set before entering into SMM
wrmsr
@@:
rsm
_SmiHandler ENDP
gcSmiHandlerSize DW $ - _SmiEntryPoint
END
|
