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|
;------------------------------------------------------------------------------ ;
; Copyright (c) 2012 - 2013, 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:
;
; ExceptionHandlerAsm.Asm
;
; Abstract:
;
; IA32 CPU Exception Handler
;
; Notes:
;
;------------------------------------------------------------------------------
.686
.model flat,C
;
; CommonExceptionHandler()
;
CommonExceptionHandler PROTO C
.data
EXTRN mErrorCodeFlag:DWORD ; Error code flags for exceptions
EXTRN mDoFarReturnFlag:DWORD ; Do far return flag
.code
ALIGN 8
;
; exception handler stub table
;
AsmIdtVectorBegin:
REPEAT 32
db 6ah ; push #VectorNum
db ($ - AsmIdtVectorBegin) / ((AsmIdtVectorEnd - AsmIdtVectorBegin) / 32) ; VectorNum
push eax
mov eax, CommonInterruptEntry
jmp eax
ENDM
AsmIdtVectorEnd:
HookAfterStubBegin:
db 6ah ; push
VectorNum:
db 0 ; 0 will be fixed
push eax
mov eax, HookAfterStubHeaderEnd
jmp eax
HookAfterStubHeaderEnd:
pop eax
sub esp, 8 ; reserve room for filling exception data later
push [esp + 8]
xchg ecx, [esp] ; get vector number
bt mErrorCodeFlag, ecx
jnc @F
push [esp] ; addition push if exception data needed
@@:
xchg ecx, [esp] ; restore ecx
push eax
;----------------------------------------------------------------------------;
; CommonInterruptEntry ;
;----------------------------------------------------------------------------;
; The follow algorithm is used for the common interrupt routine.
; Entry from each interrupt with a push eax and eax=interrupt number
; Stack:
; +---------------------+
; + EFlags +
; +---------------------+
; + CS +
; +---------------------+
; + EIP +
; +---------------------+
; + Error Code +
; +---------------------+
; + Vector Number +
; +---------------------+
; + EBP +
; +---------------------+ <-- EBP
CommonInterruptEntry PROC PUBLIC
cli
pop eax
;
; All interrupt handlers are invoked through interrupt gates, so
; IF flag automatically cleared at the entry point
;
;
; Get vector number from top of stack
;
xchg ecx, [esp]
and ecx, 0FFh ; Vector number should be less than 256
cmp ecx, 32 ; Intel reserved vector for exceptions?
jae NoErrorCode
bt mErrorCodeFlag, ecx
jc HasErrorCode
NoErrorCode:
;
; Stack:
; +---------------------+
; + EFlags +
; +---------------------+
; + CS +
; +---------------------+
; + EIP +
; +---------------------+
; + ECX +
; +---------------------+ <-- ESP
;
; Registers:
; ECX - Vector Number
;
;
; Put Vector Number on stack
;
push ecx
;
; Put 0 (dummy) error code on stack, and restore ECX
;
xor ecx, ecx ; ECX = 0
xchg ecx, [esp+4]
jmp ErrorCodeAndVectorOnStack
HasErrorCode:
;
; Stack:
; +---------------------+
; + EFlags +
; +---------------------+
; + CS +
; +---------------------+
; + EIP +
; +---------------------+
; + Error Code +
; +---------------------+
; + ECX +
; +---------------------+ <-- ESP
;
; Registers:
; ECX - Vector Number
;
;
; Put Vector Number on stack and restore ECX
;
xchg ecx, [esp]
ErrorCodeAndVectorOnStack:
push ebp
mov ebp, esp
;
; Stack:
; +---------------------+
; + EFlags +
; +---------------------+
; + CS +
; +---------------------+
; + EIP +
; +---------------------+
; + Error Code +
; +---------------------+
; + Vector Number +
; +---------------------+
; + EBP +
; +---------------------+ <-- EBP
;
;
; Align stack to make sure that EFI_FX_SAVE_STATE_IA32 of EFI_SYSTEM_CONTEXT_IA32
; is 16-byte aligned
;
and esp, 0fffffff0h
sub esp, 12
sub esp, 8
push 0 ; clear EXCEPTION_HANDLER_CONTEXT.OldIdtHandler
push 0 ; clear EXCEPTION_HANDLER_CONTEXT.ExceptionDataFlag
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
push eax
push ecx
push edx
push ebx
lea ecx, [ebp + 6 * 4]
push ecx ; ESP
push dword ptr [ebp] ; EBP
push esi
push edi
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
mov eax, ss
push eax
movzx eax, word ptr [ebp + 4 * 4]
push eax
mov eax, ds
push eax
mov eax, es
push eax
mov eax, fs
push eax
mov eax, gs
push eax
;; UINT32 Eip;
mov eax, [ebp + 3 * 4]
push eax
;; UINT32 Gdtr[2], Idtr[2];
sub esp, 8
sidt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0FFFFh
mov [esp+4], eax
sub esp, 8
sgdt [esp]
mov eax, [esp + 2]
xchg eax, [esp]
and eax, 0FFFFh
mov [esp+4], eax
;; UINT32 Ldtr, Tr;
xor eax, eax
str ax
push eax
sldt ax
push eax
;; UINT32 EFlags;
mov eax, [ebp + 5 * 4]
push eax
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
mov eax, cr4
or eax, 208h
mov cr4, eax
push eax
mov eax, cr3
push eax
mov eax, cr2
push eax
xor eax, eax
push eax
mov eax, cr0
push eax
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
mov eax, dr7
push eax
mov eax, dr6
push eax
mov eax, dr3
push eax
mov eax, dr2
push eax
mov eax, dr1
push eax
mov eax, dr0
push eax
;; FX_SAVE_STATE_IA32 FxSaveState;
sub esp, 512
mov edi, esp
db 0fh, 0aeh, 07h ;fxsave [edi]
;; UEFI calling convention for IA32 requires that Direction flag in EFLAGs is clear
cld
;; UINT32 ExceptionData;
push dword ptr [ebp + 2 * 4]
;; Prepare parameter and call
mov edx, esp
push edx
mov edx, dword ptr [ebp + 1 * 4]
push edx
;
; Call External Exception Handler
;
mov eax, CommonExceptionHandler
call eax
add esp, 8
cli
;; UINT32 ExceptionData;
add esp, 4
;; FX_SAVE_STATE_IA32 FxSaveState;
mov esi, esp
db 0fh, 0aeh, 0eh ; fxrstor [esi]
add esp, 512
;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
;; Skip restoration of DRx registers to support in-circuit emualators
;; or debuggers set breakpoint in interrupt/exception context
add esp, 4 * 6
;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4;
pop eax
mov cr0, eax
add esp, 4 ; not for Cr1
pop eax
mov cr2, eax
pop eax
mov cr3, eax
pop eax
mov cr4, eax
;; UINT32 EFlags;
pop dword ptr [ebp + 5 * 4]
;; UINT32 Ldtr, Tr;
;; UINT32 Gdtr[2], Idtr[2];
;; Best not let anyone mess with these particular registers...
add esp, 24
;; UINT32 Eip;
pop dword ptr [ebp + 3 * 4]
;; UINT32 Gs, Fs, Es, Ds, Cs, Ss;
;; NOTE - modified segment registers could hang the debugger... We
;; could attempt to insulate ourselves against this possibility,
;; but that poses risks as well.
;;
pop gs
pop fs
pop es
pop ds
pop dword ptr [ebp + 4 * 4]
pop ss
;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax;
pop edi
pop esi
add esp, 4 ; not for ebp
add esp, 4 ; not for esp
pop ebx
pop edx
pop ecx
pop eax
pop dword ptr [ebp - 8]
pop dword ptr [ebp - 4]
mov esp, ebp
pop ebp
add esp, 8
cmp dword ptr [esp - 16], 0 ; check EXCEPTION_HANDLER_CONTEXT.OldIdtHandler
jz DoReturn
cmp dword ptr [esp - 20], 1 ; check EXCEPTION_HANDLER_CONTEXT.ExceptionDataFlag
jz ErrorCode
jmp dword ptr [esp - 16]
ErrorCode:
sub esp, 4
jmp dword ptr [esp - 12]
DoReturn:
cmp mDoFarReturnFlag, 0 ; Check if need to do far return instead of IRET
jz DoIret
push [esp + 8] ; save EFLAGS
add esp, 16
push [esp - 8] ; save CS in new location
push [esp - 8] ; save EIP in new location
push [esp - 8] ; save EFLAGS in new location
popfd ; restore EFLAGS
retf ; far return
DoIret:
iretd
CommonInterruptEntry ENDP
;---------------------------------------;
; _AsmGetTemplateAddressMap ;
;----------------------------------------------------------------------------;
;
; Protocol prototype
; AsmGetTemplateAddressMap (
; EXCEPTION_HANDLER_TEMPLATE_MAP *AddressMap
; );
;
; Routine Description:
;
; Return address map of interrupt handler template so that C code can generate
; interrupt table.
;
; Arguments:
;
;
; Returns:
;
; Nothing
;
;
; Input: [ebp][0] = Original ebp
; [ebp][4] = Return address
;
; Output: Nothing
;
; Destroys: Nothing
;-----------------------------------------------------------------------------;
AsmGetTemplateAddressMap proc near public
push ebp ; C prolog
mov ebp, esp
pushad
mov ebx, dword ptr [ebp + 08h]
mov dword ptr [ebx], AsmIdtVectorBegin
mov dword ptr [ebx + 4h], (AsmIdtVectorEnd - AsmIdtVectorBegin) / 32
mov dword ptr [ebx + 8h], HookAfterStubBegin
popad
pop ebp
ret
AsmGetTemplateAddressMap ENDP
;-------------------------------------------------------------------------------------
; AsmVectorNumFixup (*NewVectorAddr, VectorNum, *OldVectorAddr);
;-------------------------------------------------------------------------------------
AsmVectorNumFixup proc near public
mov eax, dword ptr [esp + 8]
mov ecx, [esp + 4]
mov [ecx + (VectorNum - HookAfterStubBegin)], al
ret
AsmVectorNumFixup ENDP
END
|