TITLE CpuAsm.asm:
;------------------------------------------------------------------------------
;*
;* Copyright (c) 2008 - 2011, 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
;*
;* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
;* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
;*
;* CpuAsm.asm
;*
;* Abstract:
;*
;------------------------------------------------------------------------------
.code
EXTRN mErrorCodeFlag:DWORD ; Error code flags for exceptions
;
; point to the external interrupt vector table
;
ExternalVectorTablePtr QWORD 0
InitializeExternalVectorTablePtr PROC PUBLIC
mov ExternalVectorTablePtr, rcx
ret
InitializeExternalVectorTablePtr ENDP
;------------------------------------------------------------------------------
; VOID
; SetCodeSelector (
; UINT16 Selector
; );
;------------------------------------------------------------------------------
SetCodeSelector PROC PUBLIC
sub rsp, 0x10
lea rax, setCodeSelectorLongJump
mov [rsp], rax
mov [rsp+4], cx
jmp fword ptr [rsp]
setCodeSelectorLongJump:
add rsp, 0x10
ret
SetCodeSelector ENDP
;------------------------------------------------------------------------------
; VOID
; SetDataSelectors (
; UINT16 Selector
; );
;------------------------------------------------------------------------------
SetDataSelectors PROC PUBLIC
mov ss, cx
mov ds, cx
mov es, cx
mov fs, cx
mov gs, cx
ret
SetDataSelectors ENDP
;---------------------------------------;
; CommonInterruptEntry ;
;---------------------------------------;
; The follow algorithm is used for the common interrupt routine.
CommonInterruptEntry PROC PUBLIC
cli
;
; All interrupt handlers are invoked through interrupt gates, so
; IF flag automatically cleared at the entry point
;
;
; Calculate vector number
;
xchg rcx, [rsp] ; get the return address of call, actually, it is the address of vector number.
movzx ecx, word ptr [rcx]
cmp ecx, 32 ; Intel reserved vector for exceptions?
jae NoErrorCode
bt mErrorCodeFlag, ecx
jc @F
NoErrorCode:
;
; Push a dummy error code on the stack
; to maintain coherent stack map
;
push [rsp]
mov qword ptr [rsp + 8], 0
@@:
push rbp
mov rbp, rsp
;
; Stack:
; +---------------------+ <-- 16-byte aligned ensured by processor
; + Old SS +
; +---------------------+
; + Old RSP +
; +---------------------+
; + RFlags +
; +---------------------+
; + CS +
; +---------------------+
; + RIP +
; +---------------------+
; + Error Code +
; +---------------------+
; + RCX / Vector Number +
; +---------------------+
; + RBP +
; +---------------------+ <-- RBP, 16-byte aligned
;
;
; Since here the stack pointer is 16-byte aligned, so
; EFI_FX_SAVE_STATE_X64 of EFI_SYSTEM_CONTEXT_x64
; is 16-byte aligned
;
;; UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
;; UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
push r15
push r14
push r13
push r12
push r11
push r10
push r9
push r8
push rax
push qword ptr [rbp + 8] ; RCX
push rdx
push rbx
push qword ptr [rbp + 48] ; RSP
push qword ptr [rbp] ; RBP
push rsi
push rdi
;; UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero
movzx rax, word ptr [rbp + 56]
push rax ; for ss
movzx rax, word ptr [rbp + 32]
push rax ; for cs
mov rax, ds
push rax
mov rax, es
push rax
mov rax, fs
push rax
mov rax, gs
push rax
mov [rbp + 8], rcx ; save vector number
;; UINT64 Rip;
push qword ptr [rbp + 24]
;; UINT64 Gdtr[2], Idtr[2];
xor rax, rax
push rax
push rax
sidt [rsp]
xchg rax, [rsp + 2]
xchg rax, [rsp]
xchg rax, [rsp + 8]
xor rax, rax
push rax
push rax
sgdt [rsp]
xchg rax, [rsp + 2]
xchg rax, [rsp]
xchg rax, [rsp + 8]
;; UINT64 Ldtr, Tr;
xor rax, rax
str ax
push rax
sldt ax
push rax
;; UINT64 RFlags;
push qword ptr [rbp + 40]
;; UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
mov rax, cr8
push rax
mov rax, cr4
or rax, 208h
mov cr4, rax
push rax
mov rax, cr3
push rax
mov rax, cr2
push rax
xor rax, rax
push rax
mov rax, cr0
push rax
;; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
mov rax, dr7
push rax
mov rax, dr6
push rax
mov rax, dr3
push rax
mov rax, dr2
push rax
mov rax, dr1
push rax
mov rax, dr0
push rax
;; FX_SAVE_STATE_X64 FxSaveState;
sub rsp, 512
mov rdi, rsp
db 0fh, 0aeh, 07h ;fxsave [rdi]
;; UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
cld
;; UINT32 ExceptionData;
push qword ptr [rbp + 16]
;; call into exception handler
mov rcx, [rbp + 8]
mov rax, ExternalVectorTablePtr ; get the interrupt vectors base
mov rax, [rax + rcx * 8]
or rax, rax ; NULL?
je nonNullValue;
;; Prepare parameter and call
; mov rcx, [rbp + 8]
mov rdx, rsp
;
; Per X64 calling convention, allocate maximum parameter stack space
; and make sure RSP is 16-byte aligned
;
sub rsp, 4 * 8 + 8
call rax
add rsp, 4 * 8 + 8
nonNullValue:
cli
;; UINT64 ExceptionData;
add rsp, 8
;; FX_SAVE_STATE_X64 FxSaveState;
mov rsi, rsp
db 0fh, 0aeh, 0Eh ; fxrstor [rsi]
add rsp, 512
;; UINT64 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 rsp, 8 * 6
;; UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
pop rax
mov cr0, rax
add rsp, 8 ; not for Cr1
pop rax
mov cr2, rax
pop rax
mov cr3, rax
pop rax
mov cr4, rax
pop rax
mov cr8, rax
;; UINT64 RFlags;
pop qword ptr [rbp + 40]
;; UINT64 Ldtr, Tr;
;; UINT64 Gdtr[2], Idtr[2];
;; Best not let anyone mess with these particular registers...
add rsp, 48
;; UINT64 Rip;
pop qword ptr [rbp + 24]
;; UINT64 Gs, Fs, Es, Ds, Cs, Ss;
pop rax
; mov gs, rax ; not for gs
pop rax
; mov fs, rax ; not for fs
; (X64 will not use fs and gs, so we do not restore it)
pop rax
mov es, rax
pop rax
mov ds, rax
pop qword ptr [rbp + 32] ; for cs
pop qword ptr [rbp + 56] ; for ss
;; UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
;; UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
pop rdi
pop rsi
add rsp, 8 ; not for rbp
pop qword ptr [rbp + 48] ; for rsp
pop rbx
pop rdx
pop rcx
pop rax
pop r8
pop r9
pop r10
pop r11
pop r12
pop r13
pop r14
pop r15
mov rsp, rbp
pop rbp
add rsp, 16
iretq
CommonInterruptEntry ENDP
END