1 ;------------------------------------------------------------------------------ ; 2 ; Copyright (c) 2009 - 2015, Intel Corporation. All rights reserved.<BR> 3 ; This program and the accompanying materials 4 ; are licensed and made available under the terms and conditions of the BSD License 5 ; which accompanies this distribution. The full text of the license may be found at 6 ; http://opensource.org/licenses/bsd-license.php. 7 ; 8 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, 9 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. 10 ; 11 ; Module Name: 12 ; 13 ; SmiEntry.asm 14 ; 15 ; Abstract: 16 ; 17 ; Code template of the SMI handler for a particular processor 18 ; 19 ;------------------------------------------------------------------------------- 20 21 .686p 22 .model flat,C 23 .xmm 24 25 DSC_OFFSET EQU 0fb00h 26 DSC_GDTPTR EQU 30h 27 DSC_GDTSIZ EQU 38h 28 DSC_CS EQU 14 29 DSC_DS EQU 16 30 DSC_SS EQU 18 31 DSC_OTHERSEG EQU 20 32 33 PROTECT_MODE_CS EQU 08h 34 PROTECT_MODE_DS EQU 20h 35 TSS_SEGMENT EQU 40h 36 37 SmiRendezvous PROTO C 38 CpuSmmDebugEntry PROTO C 39 CpuSmmDebugExit PROTO C 40 41 EXTERNDEF gcSmiHandlerTemplate:BYTE 42 EXTERNDEF gcSmiHandlerSize:WORD 43 EXTERNDEF gSmiCr3:DWORD 44 EXTERNDEF gSmiStack:DWORD 45 EXTERNDEF gSmbase:DWORD 46 EXTERNDEF FeaturePcdGet (PcdCpuSmmStackGuard):BYTE 47 EXTERNDEF gSmiHandlerIdtr:FWORD 48 49 .code 50 51 gcSmiHandlerTemplate LABEL BYTE 52 53 _SmiEntryPoint: 54 DB 0bbh ; mov bx, imm16 55 DW offset _GdtDesc - _SmiEntryPoint + 8000h 56 DB 2eh, 0a1h ; mov ax, cs:[offset16] 57 DW DSC_OFFSET + DSC_GDTSIZ 58 dec eax 59 mov cs:[edi], eax ; mov cs:[bx], ax 60 DB 66h, 2eh, 0a1h ; mov eax, cs:[offset16] 61 DW DSC_OFFSET + DSC_GDTPTR 62 mov cs:[edi + 2], ax ; mov cs:[bx + 2], eax 63 mov bp, ax ; ebp = GDT base 64 DB 66h 65 lgdt fword ptr cs:[edi] ; lgdt fword ptr cs:[bx] 66 ; Patch ProtectedMode Segment 67 DB 0b8h ; mov ax, imm16 68 DW PROTECT_MODE_CS ; set AX for segment directly 69 mov cs:[edi - 2], eax ; mov cs:[bx - 2], ax 70 ; Patch ProtectedMode entry 71 DB 66h, 0bfh ; mov edi, SMBASE 72 gSmbase DD ? 73 DB 67h 74 lea ax, [edi + (@32bit - _SmiEntryPoint) + 8000h] 75 mov cs:[edi - 6], ax ; mov cs:[bx - 6], eax 76 mov ebx, cr0 77 DB 66h 78 and ebx, 9ffafff3h 79 DB 66h 80 or ebx, 23h 81 mov cr0, ebx 82 DB 66h, 0eah 83 DD ? 84 DW ? 85 _GdtDesc FWORD ? 86 87 @32bit: 88 mov ax, PROTECT_MODE_DS 89 mov ds, ax 90 mov es, ax 91 mov fs, ax 92 mov gs, ax 93 mov ss, ax 94 DB 0bch ; mov esp, imm32 95 gSmiStack DD ? 96 mov eax, offset gSmiHandlerIdtr 97 lidt fword ptr [eax] 98 jmp ProtFlatMode 99 100 ProtFlatMode: 101 DB 0b8h ; mov eax, imm32 102 gSmiCr3 DD ? 103 mov cr3, eax 104 ; 105 ; Need to test for CR4 specific bit support 106 ; 107 mov eax, 1 108 cpuid ; use CPUID to determine if specific CR4 bits are supported 109 xor eax, eax ; Clear EAX 110 test edx, BIT2 ; Check for DE capabilities 111 jz @f 112 or eax, BIT3 113 @@: 114 test edx, BIT6 ; Check for PAE capabilities 115 jz @f 116 or eax, BIT5 117 @@: 118 test edx, BIT7 ; Check for MCE capabilities 119 jz @f 120 or eax, BIT6 121 @@: 122 test edx, BIT24 ; Check for FXSR capabilities 123 jz @f 124 or eax, BIT9 125 @@: 126 test edx, BIT25 ; Check for SSE capabilities 127 jz @f 128 or eax, BIT10 129 @@: ; as cr4.PGE is not set here, refresh cr3 130 mov cr4, eax ; in PreModifyMtrrs() to flush TLB. 131 mov ebx, cr0 132 or ebx, 080010000h ; enable paging + WP 133 mov cr0, ebx 134 lea ebx, [edi + DSC_OFFSET] 135 mov ax, [ebx + DSC_DS] 136 mov ds, eax 137 mov ax, [ebx + DSC_OTHERSEG] 138 mov es, eax 139 mov fs, eax 140 mov gs, eax 141 mov ax, [ebx + DSC_SS] 142 mov ss, eax 143 144 cmp FeaturePcdGet (PcdCpuSmmStackGuard), 0 145 jz @F 146 147 ; Load TSS 148 mov byte ptr [ebp + TSS_SEGMENT + 5], 89h ; clear busy flag 149 mov eax, TSS_SEGMENT 150 ltr ax 151 @@: 152 ; jmp _SmiHandler ; instruction is not needed 153 154 _SmiHandler PROC 155 mov ebx, [esp] ; CPU Index 156 157 push ebx 158 mov eax, CpuSmmDebugEntry 159 call eax 160 pop ecx 161 162 push ebx 163 mov eax, SmiRendezvous 164 call eax 165 pop ecx 166 167 push ebx 168 mov eax, CpuSmmDebugExit 169 call eax 170 pop ecx 171 172 rsm 173 _SmiHandler ENDP 174 175 gcSmiHandlerSize DW $ - _SmiEntryPoint 176 177 END 178
