1 files changed, 163 insertions, 0 deletions
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
new file mode 100644
index 0000000000..4fb0c13508
--- /dev/null
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/Ia32/SmiEntry.nasm
@@ -0,0 +1,163 @@
+;------------------------------------------------------------------------------ ;
+; Copyright (c) 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.nasm
+;
+; Abstract:
+;
+;   Code template of the SMI handler for a particular processor
+;
+;-------------------------------------------------------------------------------
+
+%define DSC_OFFSET 0xfb00
+%define DSC_GDTPTR 0x30
+%define DSC_GDTSIZ 0x38
+%define DSC_CS 14
+%define DSC_DS 16
+%define DSC_SS 18
+%define DSC_OTHERSEG 20
+
+%define PROTECT_MODE_CS 0x8
+%define PROTECT_MODE_DS 0x20
+%define TSS_SEGMENT 0x40
+
+extern ASM_PFX(SmiRendezvous)
+extern ASM_PFX(FeaturePcdGet (PcdCpuSmmStackGuard))
+extern ASM_PFX(CpuSmmDebugEntry)
+extern ASM_PFX(CpuSmmDebugExit)
+
+global ASM_PFX(gcSmiHandlerTemplate)
+global ASM_PFX(gcSmiHandlerSize)
+global ASM_PFX(gSmiCr3)
+global ASM_PFX(gSmiStack)
+global ASM_PFX(gSmbase)
+extern ASM_PFX(gSmiHandlerIdtr)
+
+    SECTION .text
+
+BITS 16
+ASM_PFX(gcSmiHandlerTemplate):
+_SmiEntryPoint:
+    mov     bx, _GdtDesc - _SmiEntryPoint + 0x8000
+    mov     ax,[cs:DSC_OFFSET + DSC_GDTSIZ]
+    dec     ax
+    mov     [cs:bx], ax
+    mov     eax, [cs:DSC_OFFSET + DSC_GDTPTR]
+    mov     [cs:bx + 2], eax
+    mov     ebp, eax                      ; ebp = GDT base
+o32 lgdt    [cs:bx]                       ; lgdt fword ptr cs:[bx]
+    mov     ax, PROTECT_MODE_CS
+    mov     [cs:bx-0x2],ax    
+    DB      0x66, 0xbf                   ; mov edi, SMBASE
+ASM_PFX(gSmbase): DD 0
+    lea     eax, [edi + (@32bit - _SmiEntryPoint) + 0x8000]
+    mov     [cs:bx-0x6],eax
+    mov     ebx, cr0
+    and     ebx, 0x9ffafff3
+    or      ebx, 0x23
+    mov     cr0, ebx
+    jmp     dword 0x0:0x0
+_GdtDesc:   
+    DW 0
+    DD 0
+
+BITS 32
+@32bit:
+    mov     ax, PROTECT_MODE_DS
+o16 mov     ds, ax
+o16 mov     es, ax
+o16 mov     fs, ax
+o16 mov     gs, ax
+o16 mov     ss, ax
+    DB      0xbc                   ; mov esp, imm32
+ASM_PFX(gSmiStack): DD 0
+    mov     eax, ASM_PFX(gSmiHandlerIdtr)
+    lidt    [eax]
+    jmp     ProtFlatMode
+
+ProtFlatMode:
+    DB      0xb8                        ; mov eax, imm32
+ASM_PFX(gSmiCr3): DD 0
+    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      .0
+    or      eax, BIT3
+.0:
+    test    edx, BIT6                   ; Check for PAE capabilities
+    jz      .1
+    or      eax, BIT5
+.1:
+    test    edx, BIT7                   ; Check for MCE capabilities
+    jz      .2
+    or      eax, BIT6
+.2:
+    test    edx, BIT24                  ; Check for FXSR capabilities
+    jz      .3
+    or      eax, BIT9
+.3:
+    test    edx, BIT25                  ; Check for SSE capabilities
+    jz      .4
+    or      eax, BIT10
+.4:                                     ; as cr4.PGE is not set here, refresh cr3
+    mov     cr4, eax                    ; in PreModifyMtrrs() to flush TLB.
+    mov     ebx, cr0
+    or      ebx, 0x080010000            ; enable paging + WP
+    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     byte [dword ASM_PFX(FeaturePcdGet (PcdCpuSmmStackGuard))], 0
+    jz      .5
+
+; Load TSS
+    mov     byte [ebp + TSS_SEGMENT + 5], 0x89 ; clear busy flag
+    mov     eax, TSS_SEGMENT
+    ltr     ax
+.5:
+;   jmp     _SmiHandler                 ; instruction is not needed
+
+global ASM_PFX(SmiHandler)
+ASM_PFX(SmiHandler):
+    mov     ebx, [esp]                  ; CPU Index
+
+    push    ebx
+    mov     eax, ASM_PFX(CpuSmmDebugEntry)
+    call    eax
+    pop     ecx
+
+    push    ebx
+    mov     eax, ASM_PFX(SmiRendezvous)
+    call    eax
+    pop     ecx
+    
+    push    ebx
+    mov     eax, ASM_PFX(CpuSmmDebugExit)
+    call    eax
+    pop     ecx
+
+    rsm
+
+ASM_PFX(gcSmiHandlerSize): DW $ - _SmiEntryPoint
+