;------------------------------------------------------------------------------ ; ; Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.
; 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 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 EXTERNDEF gcSmiHandlerTemplate:BYTE EXTERNDEF gcSmiHandlerSize:WORD EXTERNDEF gSmiCr3:DWORD EXTERNDEF gSmiStack:DWORD EXTERNDEF gSmbase:DWORD EXTERNDEF FeaturePcdGet (PcdCpuSmmDebug):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. mov ebx, cr0 or ebx, 080000000h ; enable paging 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 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 _SmiHandler PROC cmp FeaturePcdGet (PcdCpuSmmDebug), 0 jz @3 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