# TITLE CpuAsm.S:
#------------------------------------------------------------------------------
#*
#* 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
#* 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.
#*
#* CpuAsm.S
#*
#* Abstract:
#*
#------------------------------------------------------------------------------
#text SEGMENT
#EXTRN ASM_PFX(mErrorCodeFlag):DWORD # Error code flags for exceptions
#
# point to the external interrupt vector table
#
ExternalVectorTablePtr:
.byte 0, 0, 0, 0, 0, 0, 0, 0
ASM_GLOBAL ASM_PFX(InitializeExternalVectorTablePtr)
ASM_PFX(InitializeExternalVectorTablePtr):
lea ExternalVectorTablePtr(%rip), %rax # save vector number
mov %rcx, (%rax)
ret
#------------------------------------------------------------------------------
# VOID
# SetCodeSelector (
# UINT16 Selector
# );
#------------------------------------------------------------------------------
ASM_GLOBAL ASM_PFX(SetCodeSelector)
ASM_PFX(SetCodeSelector):
subq $0x10, %rsp
leaq L_setCodeSelectorLongJump(%rip), %rax
movq %rax, (%rsp)
movw %cx, 4(%rsp)
.byte 0xFF, 0x2C, 0x24 # jmp (%rsp) note:fword jmp
L_setCodeSelectorLongJump:
addq $0x10, %rsp
ret
#------------------------------------------------------------------------------
# VOID
# SetDataSelectors (
# UINT16 Selector
# );
#------------------------------------------------------------------------------
ASM_GLOBAL ASM_PFX(SetDataSelectors)
ASM_PFX(SetDataSelectors):
movw %cx, %ss
movw %cx, %ds
movw %cx, %es
movw %cx, %fs
movw %cx, %gs
ret
#---------------------------------------;
# CommonInterruptEntry ;
#---------------------------------------;
# The follow algorithm is used for the common interrupt routine.
ASM_GLOBAL ASM_PFX(CommonInterruptEntry)
ASM_PFX(CommonInterruptEntry):
cli
#
# All interrupt handlers are invoked through interrupt gates, so
# IF flag automatically cleared at the entry point
#
#
# Calculate vector number
#
xchgq (%rsp), %rcx # get the return address of call, actually, it is the address of vector number.
movzwl (%rcx), %ecx
cmp $32, %ecx # Intel reserved vector for exceptions?
jae NoErrorCode
pushq %rax
leaq ASM_PFX(mErrorCodeFlag)(%rip), %rax
bt %ecx, (%rax)
popq %rax
jc CommonInterruptEntry_al_0000
NoErrorCode:
#
# Push a dummy error code on the stack
# to maintain coherent stack map
#
pushq (%rsp)
movq $0, 8(%rsp)
CommonInterruptEntry_al_0000:
pushq %rbp
movq %rsp, %rbp
#
# 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;
pushq %r15
pushq %r14
pushq %r13
pushq %r12
pushq %r11
pushq %r10
pushq %r9
pushq %r8
pushq %rax
pushq 8(%rbp) # RCX
pushq %rdx
pushq %rbx
pushq 48(%rbp) # RSP
pushq (%rbp) # RBP
pushq %rsi
pushq %rdi
#; UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero
movzwq 56(%rbp), %rax
pushq %rax # for ss
movzwq 32(%rbp), %rax
pushq %rax # for cs
movl %ds, %eax
pushq %rax
movl %es, %eax
pushq %rax
movl %fs, %eax
pushq %rax
movl %gs, %eax
pushq %rax
movq %rcx, 8(%rbp) # save vector number
#; UINT64 Rip;
pushq 24(%rbp)
#; UINT64 Gdtr[2], Idtr[2];
xorq %rax, %rax
pushq %rax
pushq %rax
sidt (%rsp)
xchgq 2(%rsp), %rax
xchgq (%rsp), %rax
xchgq 8(%rsp), %rax
xorq %rax, %rax
pushq %rax
pushq %rax
sgdt (%rsp)
xchgq 2(%rsp), %rax
xchgq (%rsp), %rax
xchgq 8(%rsp), %rax
#; UINT64 Ldtr, Tr;
xorq %rax, %rax
str %ax
pushq %rax
sldt %ax
pushq %rax
#; UINT64 RFlags;
pushq 40(%rbp)
#; UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
movq %cr8, %rax
pushq %rax
movq %cr4, %rax
orq $0x208, %rax
movq %rax, %cr4
pushq %rax
mov %cr3, %rax
pushq %rax
mov %cr2, %rax
pushq %rax
xorq %rax, %rax
pushq %rax
mov %cr0, %rax
pushq %rax
#; UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
movq %dr7, %rax
pushq %rax
movq %dr6, %rax
pushq %rax
movq %dr3, %rax
pushq %rax
movq %dr2, %rax
pushq %rax
movq %dr1, %rax
pushq %rax
movq %dr0, %rax
pushq %rax
#; FX_SAVE_STATE_X64 FxSaveState;
subq $512, %rsp
movq %rsp, %rdi
.byte 0x0f, 0x0ae, 0x07 #fxsave [rdi]
#; UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
cld
#; UINT32 ExceptionData;
pushq 16(%rbp)
#; call into exception handler
movq 8(%rbp), %rcx
leaq ExternalVectorTablePtr(%rip), %rax
movl (%eax), %eax
movq (%rax,%rcx,8), %rax
orq %rax, %rax # NULL?
je nonNullValue#
#; Prepare parameter and call
# mov rcx, [rbp + 8]
mov %rsp, %rdx
#
# Per X64 calling convention, allocate maximum parameter stack space
# and make sure RSP is 16-byte aligned
#
subq $40, %rsp
call *%rax
addq $40, %rsp
nonNullValue:
cli
#; UINT64 ExceptionData;
addq $8, %rsp
#; FX_SAVE_STATE_X64 FxSaveState;
movq %rsp, %rsi
.byte 0x0f, 0x0ae, 0x0E # fxrstor [rsi]
addq $512, %rsp
#; 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
addq $48, %rsp
#; UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
popq %rax
movq %rax, %cr0
addq $8, %rsp # not for Cr1
popq %rax
movq %rax, %cr2
popq %rax
movq %rax, %cr3
popq %rax
movq %rax, %cr4
popq %rax
movq %rax, %cr8
#; UINT64 RFlags;
popq 40(%rbp)
#; UINT64 Ldtr, Tr;
#; UINT64 Gdtr[2], Idtr[2];
#; Best not let anyone mess with these particular registers...
addq $48, %rsp
#; UINT64 Rip;
popq 24(%rbp)
#; UINT64 Gs, Fs, Es, Ds, Cs, Ss;
popq %rax
# mov %rax, %gs ; not for gs
popq %rax
# mov %rax, %fs ; not for fs
# (X64 will not use fs and gs, so we do not restore it)
popq %rax
movl %eax, %es
popq %rax
movl %eax, %ds
popq 32(%rbp) # for cs
popq 56(%rbp) # for ss
#; UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
#; UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
popq %rdi
popq %rsi
addq $8, %rsp # not for rbp
popq 48(%rbp) # for rsp
popq %rbx
popq %rdx
popq %rcx
popq %rax
popq %r8
popq %r9
popq %r10
popq %r11
popq %r12
popq %r13
popq %r14
popq %r15
movq %rbp, %rsp
popq %rbp
addq $16, %rsp
iretq
#text ENDS
#END