X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdeModulePkg%2FUniversal%2FDebugSupportDxe%2FX64%2FAsmFuncs.S;fp=MdeModulePkg%2FUniversal%2FDebugSupportDxe%2FX64%2FAsmFuncs.S;h=9783ec6b803806a027e40a1bc243ea0da5ebff02;hp=e6a40e8daddad49f7fffcee8304fbde87e036cc6;hb=4b738c76f56f8eda171f14b8f9b20e34b66be476;hpb=4c8f6044a2ae275071ab6cd6557b584784c093ce
diff --git a/MdeModulePkg/Universal/DebugSupportDxe/X64/AsmFuncs.S b/MdeModulePkg/Universal/DebugSupportDxe/X64/AsmFuncs.S
index e6a40e8dad..9783ec6b80 100644
--- a/MdeModulePkg/Universal/DebugSupportDxe/X64/AsmFuncs.S
+++ b/MdeModulePkg/Universal/DebugSupportDxe/X64/AsmFuncs.S
@@ -1,551 +1,551 @@
-///**@file
-// Low leve x64 specific debug support functions.
-//
-// Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.
-// Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
-// 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.
-//
-//**/
-
-ASM_GLOBAL ASM_PFX(OrigVector)
-ASM_GLOBAL ASM_PFX(InterruptEntryStub)
-ASM_GLOBAL ASM_PFX(StubSize)
-ASM_GLOBAL ASM_PFX(CommonIdtEntry)
-ASM_GLOBAL ASM_PFX(FxStorSupport)
-
-.data
-
-ASM_PFX(StubSize): .long ASM_PFX(InterruptEntryStubEnd) - ASM_PFX(InterruptEntryStub)
-ASM_PFX(AppRsp): .long 0x11111111 # ?
- .long 0x11111111 # ?
-ASM_PFX(DebugRsp): .long 0x22222222 # ?
- .long 0x22222222 # ?
-ASM_PFX(ExtraPush): .long 0x33333333 # ?
- .long 0x33333333 # ?
-ASM_PFX(ExceptData): .long 0x44444444 # ?
- .long 0x44444444 # ?
-ASM_PFX(Rflags): .long 0x55555555 # ?
- .long 0x55555555 # ?
-ASM_PFX(OrigVector): .long 0x66666666 # ?
- .long 0x66666666 # ?
-
-// The declarations below define the memory region that will be used for the debug stack.
-// The context record will be built by pushing register values onto this stack.
-// It is imparitive that alignment be carefully managed, since the FXSTOR and
-// FXRSTOR instructions will GP fault if their memory operand is not 16 byte aligned.
-//
-// The stub will switch stacks from the application stack to the debuger stack
-// and pushes the exception number.
-//
-// Then we building the context record on the stack. Since the stack grows down,
-// we push the fields of the context record from the back to the front. There
-// are 336 bytes of stack used prior allocating the 512 bytes of stack to be
-// used as the memory buffer for the fxstor instruction. Therefore address of
-// the buffer used for the FXSTOR instruction is &Eax - 336 - 512, which
-// must be 16 byte aligned.
-//
-// We carefully locate the stack to make this happen.
-//
-// For reference, the context structure looks like this:
-// struct {
-// UINT64 ExceptionData;
-// FX_SAVE_STATE_X64 FxSaveState; // 512 bytes, must be 16 byte aligned
-// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
-// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
-// UINT64 RFlags;
-// UINT64 Ldtr, Tr;
-// UINT64 Gdtr[2], Idtr[2];
-// UINT64 Rip;
-// UINT64 Gs, Fs, Es, Ds, Cs, Ss;
-// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
-// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
-// } SYSTEM_CONTEXT_X64; // 64 bit system context record
-
-.p2align 4
-DebugStackEnd : .ascii "DbgStkEnd >>>>>>" # 16 byte long string - must be 16 bytes to preserve alignment
- .fill 0x1ffc, 4, 0x00000000
- # 32K should be enough stack
- # This allocation is coocked to insure
- # that the the buffer for the FXSTORE instruction
- # will be 16 byte aligned also.
- #
-ASM_PFX(ExceptionNumber): .long 0x77777777 # first entry will be the vector number pushed by the stub
- .long 0x77777777 # ?
-
-DebugStackBegin : .ascii "<<<< DbgStkBegin" # initial debug ESP == DebugStackBegin, set in stub
-
-
-.text
-
-//------------------------------------------------------------------------------
-// BOOLEAN
-// FxStorSupport (
-// void
-// )
-//
-// Abstract: Returns TRUE if FxStor instructions are supported
-//
-ASM_GLOBAL ASM_PFX(FxStorSupport)
-ASM_PFX(FxStorSupport):
-//
-// cpuid corrupts rbx which must be preserved per the C calling convention
-//
- pushq %rbx
- movq $1, %rax
- cpuid
- movl %edx, %eax
- andq $0x01000000, %rax
- shrq $24, %rax
- popq %rbx
- ret
-//------------------------------------------------------------------------------
-// void
-// Vect2Desc (
-// IA32_IDT_GATE_DESCRIPTOR * DestDesc, // rcx
-// void (*Vector) (void) // rdx
-// )
-//
-// Abstract: Encodes an IDT descriptor with the given physical address
-//
-ASM_GLOBAL ASM_PFX(Vect2Desc)
-ASM_PFX(Vect2Desc):
- movq %rdx, %rax
- movw %ax, (%rcx) # write bits 15..0 of offset
- movw %cs, %dx
- movw %dx, 2(%rcx) # SYS_CODE_SEL from GDT
- movw $(0x0e00 | 0x8000), 4(%rcx) # type = 386 interrupt gate, present
- shrq $16, %rax
- movw %ax, 6(%rcx) # write bits 31..16 of offset
- shrq $16, %rax
- movl %eax, 8(%rcx) # write bits 63..32 of offset
-
- ret
-
-//------------------------------------------------------------------------------
-// InterruptEntryStub
-//
-// Abstract: This code is not a function, but is a small piece of code that is
-// copied and fixed up once for each IDT entry that is hooked.
-//
-ASM_GLOBAL ASM_PFX(InterruptEntryStub)
-ASM_PFX(InterruptEntryStub):
-
- pushq $0 # push vector number - will be modified before installed
- jmp ASM_PFX(CommonIdtEntry)
-
-ASM_GLOBAL ASM_PFX(InterruptEntryStubEnd)
-ASM_PFX(InterruptEntryStubEnd):
-
-//------------------------------------------------------------------------------
-// CommonIdtEntry
-//
-// Abstract: This code is not a function, but is the common part for all IDT
-// vectors.
-//
-ASM_GLOBAL ASM_PFX(CommonIdtEntry)
-//
-// At this point, the stub has saved the current application stack esp into AppRsp
-// and switched stacks to the debug stack, where it pushed the vector number
-//
-// The application stack looks like this:
-//
-// ...
-// (last application stack entry)
-// [16 bytes alignment, do not care it]
-// SS from interrupted task
-// RSP from interrupted task
-// rflags from interrupted task
-// CS from interrupted task
-// RIP from interrupted task
-// Error code <-------------------- Only present for some exeption types
-//
-// Vector Number <----------------- pushed in our IDT Entry
-//
-
-
-// The stub switched us to the debug stack and pushed the interrupt number.
-//
-// Next, construct the context record. It will be build on the debug stack by
-// pushing the registers in the correct order so as to create the context structure
-// on the debug stack. The context record must be built from the end back to the
-// beginning because the stack grows down...
-//
-// For reference, the context record looks like this:
-//
-// typedef
-// struct {
-// UINT64 ExceptionData;
-// FX_SAVE_STATE_X64 FxSaveState;
-// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
-// UINT64 Cr0, Cr2, Cr3, Cr4, Cr8;
-// UINT64 RFlags;
-// UINT64 Ldtr, Tr;
-// UINT64 Gdtr[2], Idtr[2];
-// UINT64 Rip;
-// UINT64 Gs, Fs, Es, Ds, Cs, Ss;
-// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
-// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
-// } SYSTEM_CONTEXT_X64; // 64
-ASM_PFX(CommonIdtEntry):
-// NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp
- pushq %rax
- movq (8)(%rsp), %rax # save vector number
- movq %rax, ASM_PFX(ExceptionNumber)(%rip) # save vector number
- popq %rax
- addq $8, %rsp # pop vector number
- movq %rsp, ASM_PFX(AppRsp)(%rip) # save stack top
- movq DebugStackBegin(%rip), %rsp # switch to debugger stack
- subq $8, %rsp # leave space for vector number
-// 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 %rcx
- pushq %rdx
- pushq %rbx
- pushq %rsp
- pushq %rbp
- pushq %rsi
- pushq %rdi
-// Save interrupt state rflags register...
- pushfq
- popq %rax
- movq %rax, ASM_PFX(Rflags)(%rip)
-// We need to determine if any extra data was pushed by the exception, and if so, save it
-// To do this, we check the exception number pushed by the stub, and cache the
-// result in a variable since we'll need this again.
- cmpl $0, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $10, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $11, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $12, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $13, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $14, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- cmpl $17, ASM_PFX(ExceptionNumber)(%rip)
- jz ExtraPushOne
- movl $0, ASM_PFX(ExtraPush)(%rip)
- movl $0, ASM_PFX(ExceptData)(%rip)
- jmp ExtraPushDone
-ExtraPushOne:
- movl $1, ASM_PFX(ExtraPush)(%rip)
-
-// If there's some extra data, save it also, and modify the saved AppRsp to effectively
-// pop this value off the application's stack.
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq (%rax), %rbx
- movq %rbx, ASM_PFX(ExceptData)(%rip)
- addq $8, %rax
- movq %rax, ASM_PFX(AppRsp)(%rip)
-
-ExtraPushDone:
-
-// The "push" above pushed the debug stack rsp. Since what we're actually doing
-// is building the context record on the debug stack, we need to save the pushed
-// debug RSP, and replace it with the application's last stack entry...
- movq 24(%rsp), %rax
- movq %rax, ASM_PFX(DebugRsp)(%rip)
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq 24(%rax), %rax
- # application stack has ss, rsp, rflags, cs, & rip, so
- # last actual application stack entry is saved at offset
- # 24 bytes from stack top.
- movq %rax, 24(%rsp)
-
-// continue building context record
-// UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero
- mov %ss, %rax
- pushq %rax
- # CS from application is one entry back in application stack
- movq ASM_PFX(AppRsp)(%rip), %rax
- movzxw 8(%rax), %rax
- pushq %rax
-
- mov %ds, %rax
- pushq %rax
- movw %es, %rax
- pushq %rax
- mov %fs, %rax
- pushq %rax
- mov %gs, %rax
- pushq %rax
-// UINT64 Rip;
- # Rip from application is on top of application stack
- movq ASM_PFX(AppRsp)(%rip), %rax
- pushq (%rax)
-// UINT64 Gdtr[2], Idtr[2];
- push $0
- push $0
- sidtq (%rsp)
- push $0
- push $0
- sgdtq (%rsp)
-
-// UINT64 Ldtr, Tr;
- xorq %rax, %rax
- str %ax
- pushq %rax
- sldt %ax
- pushq %rax
-
-// UINT64 RFlags;
-// Rflags from application is two entries back in application stack
- movq ASM_PFX(AppRsp)(%rip), %rax
- pushq 16(%rax)
-// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
-// insure FXSAVE/FXRSTOR is enabled in CR4...
-// ... while we're at it, make sure DE is also enabled...
- movq %cr8, %rax
- pushq %rax
- movq %cr4, %rax
- orq $0x208, %rax
- movq %rax, %cr4
- pushq %rax
- movq %cr3, %rax
- pushq %rax
- movq %cr2, %rax
- pushq %rax
- push $0
- movq %cr0, %rax
- pushq %rax
-// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
- movq %dr7, %rax
- pushq %rax
-// clear Dr7 while executing debugger itself
- xorq %rax, %rax
- movq %rax, %dr7
-
- movq %dr6, %rax
- pushq %rax
-// insure all status bits in dr6 are clear...
- xorq %rax, %rax
- movq %rax, %dr6
-
- 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
- # IMPORTANT!! The debug stack has been carefully constructed to
- # insure that rsp and rdi are 16 byte aligned when we get here.
- # They MUST be. If they are not, a GP fault will occur.
-
- # FXSTOR_RDI
- fxsave (%rdi)
-
-// UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
- cld
-
-// UINT64 ExceptionData;
- movq ASM_PFX(ExceptData)(%rip), %rax
- pushq %rax
-
-// call to C code which will in turn call registered handler
-// pass in the vector number
- movq %rsp, %rdx
- movq ASM_PFX(ExceptionNumber)(%rip), %rcx
- subq $40, %rsp
- call ASM_PFX(InterruptDistrubutionHub)
- addq $40, %rsp
-// restore context...
-// UINT64 ExceptionData;
- addq $8, %rsp
-
-// FX_SAVE_STATE_X64 FxSaveState;
- movq %rsp, %rsi
-
- # FXRSTOR_RSI
- fxrstor (%rsi)
-
- addq $512, %rsp
-
-// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
- popq %rax
- movq %rax, %dr0
- popq %rax
- movq %rax, %dr1
- popq %rax
- movq %rax, %dr2
- popq %rax
- movq %rax, %dr3
-
-// skip restore of dr6. We cleared dr6 during the context save.
- addq $8, %rsp
- popq %rax
- movq %rax, %dr7
-
-// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
- popq %rax
- movq %rax, %cr0
- addq $8, %rsp
- popq %rax
- movq %rax, %cr2
- popq %rax
- movq %rax, %cr3
- popq %rax
- movq %rax, %cr4
- popq %rax
- movq %rax, %cr8
-// UINT64 RFlags;
- movq ASM_PFX(AppRsp)(%rip), %rax
- popq 16(%rax)
-// UINT64 Ldtr, Tr;
-// UINT64 Gdtr[2], Idtr[2];
-// Best not let anyone mess with these particular registers...
- addq $48, %rsp
-// UINT64 Rip;
- popq (%rax)
-
-// UINT64 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.
-//
-
- popq %rax
- # mov %rax, %gs
- popq %rax
- # mov %rax, %fs
- popq %rax
- mov %rax, %es
- popq %rax
- mov %rax, %ds
- movq ASM_PFX(AppRsp)(%rip), %rax
- popq 8(%rax)
- popq %rax
- mov %rax, %ss
-## The next stuff to restore is the general purpose registers that were pushed
-## using the "push" instruction.
-##
-## The value of RSP as stored in the context record is the application RSP
-## including the 5 entries on the application stack caused by the exception
-## itself. It may have been modified by the debug agent, so we need to
-## determine if we need to relocate the application stack.
-
- movq 24(%rsp), %rbx # move the potentially modified AppRsp into rbx
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq 24(%rax), %rax
- cmpq %rax, %rbx
- je NoAppStackMove
-
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq (%rax), %rcx # RIP
- movq %rcx, (%rbx)
-
- movq 8(%rax), %rcx # CS
- movq %rcx, 8(%rbx)
-
- movq 16(%rax), %rcx # RFLAGS
- movq %rcx, 16(%rbx)
-
- movq 24(%rax), %rcx # RSP
- movq %rcx, 24(%rbx)
-
- movq 32(%rax), %rcx # SS
- movq %rcx, 32(%rbx)
-
- movq %rbx, %rax # modify the saved AppRsp to the new AppRsp
- movq %rax, ASM_PFX(AppRsp)(%rip)
-NoAppStackMove:
- movq ASM_PFX(DebugRsp)(%rip), %rax # restore the DebugRsp on the debug stack
- # so our "pop" will not cause a stack switch
- movq %rax, 24(%rsp)
-
- cmpl $0x068, ASM_PFX(ExceptionNumber)(%rip)
- jne NoChain
-
-Chain:
-
-// Restore rflags so when we chain, the flags will be exactly as if we were never here.
-// We gin up the stack to do an iretq so we can get ALL the flags.
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq 40(%rax), %rbx
- pushq %rbx
- mov %ss, %rax
- pushq %rax
- movq %rsp, %rax
- addq $16, %rax
- pushq %rax
- movq ASM_PFX(AppRsp)(%rip), %rax
- movq 16(%rax), %rbx
- andq $0xfffffffffffffcff, %rbx # special handling for IF and TF
- pushq %rbx
- mov %cs, %rax
- pushq %rax
- movq PhonyIretq(%rip), %rax
- pushq %rax
- iretq
-PhonyIretq:
-
-// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
-// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
- popq %rdi
- popq %rsi
- popq %rbp
- popq %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
-
-// Switch back to application stack
- movq ASM_PFX(AppRsp)(%rip), %rsp
-// Jump to original handler
- jmp ASM_PFX(OrigVector)
-NoChain:
-// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
-// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
- popq %rdi
- popq %rsi
- popq %rbp
- popq %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
-
-// Switch back to application stack
- movq ASM_PFX(AppRsp)(%rip), %rsp
-
-// We're outa here...
- iret
+///**@file
+// Low leve x64 specific debug support functions.
+//
+// Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.
+// Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.
+// 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.
+//
+//**/
+
+ASM_GLOBAL ASM_PFX(OrigVector)
+ASM_GLOBAL ASM_PFX(InterruptEntryStub)
+ASM_GLOBAL ASM_PFX(StubSize)
+ASM_GLOBAL ASM_PFX(CommonIdtEntry)
+ASM_GLOBAL ASM_PFX(FxStorSupport)
+
+.data
+
+ASM_PFX(StubSize): .long ASM_PFX(InterruptEntryStubEnd) - ASM_PFX(InterruptEntryStub)
+ASM_PFX(AppRsp): .long 0x11111111 # ?
+ .long 0x11111111 # ?
+ASM_PFX(DebugRsp): .long 0x22222222 # ?
+ .long 0x22222222 # ?
+ASM_PFX(ExtraPush): .long 0x33333333 # ?
+ .long 0x33333333 # ?
+ASM_PFX(ExceptData): .long 0x44444444 # ?
+ .long 0x44444444 # ?
+ASM_PFX(Rflags): .long 0x55555555 # ?
+ .long 0x55555555 # ?
+ASM_PFX(OrigVector): .long 0x66666666 # ?
+ .long 0x66666666 # ?
+
+// The declarations below define the memory region that will be used for the debug stack.
+// The context record will be built by pushing register values onto this stack.
+// It is imparitive that alignment be carefully managed, since the FXSTOR and
+// FXRSTOR instructions will GP fault if their memory operand is not 16 byte aligned.
+//
+// The stub will switch stacks from the application stack to the debuger stack
+// and pushes the exception number.
+//
+// Then we building the context record on the stack. Since the stack grows down,
+// we push the fields of the context record from the back to the front. There
+// are 336 bytes of stack used prior allocating the 512 bytes of stack to be
+// used as the memory buffer for the fxstor instruction. Therefore address of
+// the buffer used for the FXSTOR instruction is &Eax - 336 - 512, which
+// must be 16 byte aligned.
+//
+// We carefully locate the stack to make this happen.
+//
+// For reference, the context structure looks like this:
+// struct {
+// UINT64 ExceptionData;
+// FX_SAVE_STATE_X64 FxSaveState; // 512 bytes, must be 16 byte aligned
+// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
+// UINT64 RFlags;
+// UINT64 Ldtr, Tr;
+// UINT64 Gdtr[2], Idtr[2];
+// UINT64 Rip;
+// UINT64 Gs, Fs, Es, Ds, Cs, Ss;
+// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
+// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
+// } SYSTEM_CONTEXT_X64; // 64 bit system context record
+
+.p2align 4
+DebugStackEnd : .ascii "DbgStkEnd >>>>>>" # 16 byte long string - must be 16 bytes to preserve alignment
+ .fill 0x1ffc, 4, 0x00000000
+ # 32K should be enough stack
+ # This allocation is coocked to insure
+ # that the the buffer for the FXSTORE instruction
+ # will be 16 byte aligned also.
+ #
+ASM_PFX(ExceptionNumber): .long 0x77777777 # first entry will be the vector number pushed by the stub
+ .long 0x77777777 # ?
+
+DebugStackBegin : .ascii "<<<< DbgStkBegin" # initial debug ESP == DebugStackBegin, set in stub
+
+
+.text
+
+//------------------------------------------------------------------------------
+// BOOLEAN
+// FxStorSupport (
+// void
+// )
+//
+// Abstract: Returns TRUE if FxStor instructions are supported
+//
+ASM_GLOBAL ASM_PFX(FxStorSupport)
+ASM_PFX(FxStorSupport):
+//
+// cpuid corrupts rbx which must be preserved per the C calling convention
+//
+ pushq %rbx
+ movq $1, %rax
+ cpuid
+ movl %edx, %eax
+ andq $0x01000000, %rax
+ shrq $24, %rax
+ popq %rbx
+ ret
+//------------------------------------------------------------------------------
+// void
+// Vect2Desc (
+// IA32_IDT_GATE_DESCRIPTOR * DestDesc, // rcx
+// void (*Vector) (void) // rdx
+// )
+//
+// Abstract: Encodes an IDT descriptor with the given physical address
+//
+ASM_GLOBAL ASM_PFX(Vect2Desc)
+ASM_PFX(Vect2Desc):
+ movq %rdx, %rax
+ movw %ax, (%rcx) # write bits 15..0 of offset
+ movw %cs, %dx
+ movw %dx, 2(%rcx) # SYS_CODE_SEL from GDT
+ movw $(0x0e00 | 0x8000), 4(%rcx) # type = 386 interrupt gate, present
+ shrq $16, %rax
+ movw %ax, 6(%rcx) # write bits 31..16 of offset
+ shrq $16, %rax
+ movl %eax, 8(%rcx) # write bits 63..32 of offset
+
+ ret
+
+//------------------------------------------------------------------------------
+// InterruptEntryStub
+//
+// Abstract: This code is not a function, but is a small piece of code that is
+// copied and fixed up once for each IDT entry that is hooked.
+//
+ASM_GLOBAL ASM_PFX(InterruptEntryStub)
+ASM_PFX(InterruptEntryStub):
+
+ pushq $0 # push vector number - will be modified before installed
+ jmp ASM_PFX(CommonIdtEntry)
+
+ASM_GLOBAL ASM_PFX(InterruptEntryStubEnd)
+ASM_PFX(InterruptEntryStubEnd):
+
+//------------------------------------------------------------------------------
+// CommonIdtEntry
+//
+// Abstract: This code is not a function, but is the common part for all IDT
+// vectors.
+//
+ASM_GLOBAL ASM_PFX(CommonIdtEntry)
+//
+// At this point, the stub has saved the current application stack esp into AppRsp
+// and switched stacks to the debug stack, where it pushed the vector number
+//
+// The application stack looks like this:
+//
+// ...
+// (last application stack entry)
+// [16 bytes alignment, do not care it]
+// SS from interrupted task
+// RSP from interrupted task
+// rflags from interrupted task
+// CS from interrupted task
+// RIP from interrupted task
+// Error code <-------------------- Only present for some exeption types
+//
+// Vector Number <----------------- pushed in our IDT Entry
+//
+
+
+// The stub switched us to the debug stack and pushed the interrupt number.
+//
+// Next, construct the context record. It will be build on the debug stack by
+// pushing the registers in the correct order so as to create the context structure
+// on the debug stack. The context record must be built from the end back to the
+// beginning because the stack grows down...
+//
+// For reference, the context record looks like this:
+//
+// typedef
+// struct {
+// UINT64 ExceptionData;
+// FX_SAVE_STATE_X64 FxSaveState;
+// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+// UINT64 Cr0, Cr2, Cr3, Cr4, Cr8;
+// UINT64 RFlags;
+// UINT64 Ldtr, Tr;
+// UINT64 Gdtr[2], Idtr[2];
+// UINT64 Rip;
+// UINT64 Gs, Fs, Es, Ds, Cs, Ss;
+// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
+// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
+// } SYSTEM_CONTEXT_X64; // 64
+ASM_PFX(CommonIdtEntry):
+// NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp
+ pushq %rax
+ movq (8)(%rsp), %rax # save vector number
+ movq %rax, ASM_PFX(ExceptionNumber)(%rip) # save vector number
+ popq %rax
+ addq $8, %rsp # pop vector number
+ movq %rsp, ASM_PFX(AppRsp)(%rip) # save stack top
+ movq DebugStackBegin(%rip), %rsp # switch to debugger stack
+ subq $8, %rsp # leave space for vector number
+// 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 %rcx
+ pushq %rdx
+ pushq %rbx
+ pushq %rsp
+ pushq %rbp
+ pushq %rsi
+ pushq %rdi
+// Save interrupt state rflags register...
+ pushfq
+ popq %rax
+ movq %rax, ASM_PFX(Rflags)(%rip)
+// We need to determine if any extra data was pushed by the exception, and if so, save it
+// To do this, we check the exception number pushed by the stub, and cache the
+// result in a variable since we'll need this again.
+ cmpl $0, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $10, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $11, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $12, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $13, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $14, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ cmpl $17, ASM_PFX(ExceptionNumber)(%rip)
+ jz ExtraPushOne
+ movl $0, ASM_PFX(ExtraPush)(%rip)
+ movl $0, ASM_PFX(ExceptData)(%rip)
+ jmp ExtraPushDone
+ExtraPushOne:
+ movl $1, ASM_PFX(ExtraPush)(%rip)
+
+// If there's some extra data, save it also, and modify the saved AppRsp to effectively
+// pop this value off the application's stack.
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq (%rax), %rbx
+ movq %rbx, ASM_PFX(ExceptData)(%rip)
+ addq $8, %rax
+ movq %rax, ASM_PFX(AppRsp)(%rip)
+
+ExtraPushDone:
+
+// The "push" above pushed the debug stack rsp. Since what we're actually doing
+// is building the context record on the debug stack, we need to save the pushed
+// debug RSP, and replace it with the application's last stack entry...
+ movq 24(%rsp), %rax
+ movq %rax, ASM_PFX(DebugRsp)(%rip)
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq 24(%rax), %rax
+ # application stack has ss, rsp, rflags, cs, & rip, so
+ # last actual application stack entry is saved at offset
+ # 24 bytes from stack top.
+ movq %rax, 24(%rsp)
+
+// continue building context record
+// UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero
+ mov %ss, %rax
+ pushq %rax
+ # CS from application is one entry back in application stack
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movzxw 8(%rax), %rax
+ pushq %rax
+
+ mov %ds, %rax
+ pushq %rax
+ movw %es, %rax
+ pushq %rax
+ mov %fs, %rax
+ pushq %rax
+ mov %gs, %rax
+ pushq %rax
+// UINT64 Rip;
+ # Rip from application is on top of application stack
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ pushq (%rax)
+// UINT64 Gdtr[2], Idtr[2];
+ push $0
+ push $0
+ sidtq (%rsp)
+ push $0
+ push $0
+ sgdtq (%rsp)
+
+// UINT64 Ldtr, Tr;
+ xorq %rax, %rax
+ str %ax
+ pushq %rax
+ sldt %ax
+ pushq %rax
+
+// UINT64 RFlags;
+// Rflags from application is two entries back in application stack
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ pushq 16(%rax)
+// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
+// insure FXSAVE/FXRSTOR is enabled in CR4...
+// ... while we're at it, make sure DE is also enabled...
+ movq %cr8, %rax
+ pushq %rax
+ movq %cr4, %rax
+ orq $0x208, %rax
+ movq %rax, %cr4
+ pushq %rax
+ movq %cr3, %rax
+ pushq %rax
+ movq %cr2, %rax
+ pushq %rax
+ push $0
+ movq %cr0, %rax
+ pushq %rax
+// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+ movq %dr7, %rax
+ pushq %rax
+// clear Dr7 while executing debugger itself
+ xorq %rax, %rax
+ movq %rax, %dr7
+
+ movq %dr6, %rax
+ pushq %rax
+// insure all status bits in dr6 are clear...
+ xorq %rax, %rax
+ movq %rax, %dr6
+
+ 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
+ # IMPORTANT!! The debug stack has been carefully constructed to
+ # insure that rsp and rdi are 16 byte aligned when we get here.
+ # They MUST be. If they are not, a GP fault will occur.
+
+ # FXSTOR_RDI
+ fxsave (%rdi)
+
+// UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
+ cld
+
+// UINT64 ExceptionData;
+ movq ASM_PFX(ExceptData)(%rip), %rax
+ pushq %rax
+
+// call to C code which will in turn call registered handler
+// pass in the vector number
+ movq %rsp, %rdx
+ movq ASM_PFX(ExceptionNumber)(%rip), %rcx
+ subq $40, %rsp
+ call ASM_PFX(InterruptDistrubutionHub)
+ addq $40, %rsp
+// restore context...
+// UINT64 ExceptionData;
+ addq $8, %rsp
+
+// FX_SAVE_STATE_X64 FxSaveState;
+ movq %rsp, %rsi
+
+ # FXRSTOR_RSI
+ fxrstor (%rsi)
+
+ addq $512, %rsp
+
+// UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
+ popq %rax
+ movq %rax, %dr0
+ popq %rax
+ movq %rax, %dr1
+ popq %rax
+ movq %rax, %dr2
+ popq %rax
+ movq %rax, %dr3
+
+// skip restore of dr6. We cleared dr6 during the context save.
+ addq $8, %rsp
+ popq %rax
+ movq %rax, %dr7
+
+// UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
+ popq %rax
+ movq %rax, %cr0
+ addq $8, %rsp
+ popq %rax
+ movq %rax, %cr2
+ popq %rax
+ movq %rax, %cr3
+ popq %rax
+ movq %rax, %cr4
+ popq %rax
+ movq %rax, %cr8
+// UINT64 RFlags;
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ popq 16(%rax)
+// UINT64 Ldtr, Tr;
+// UINT64 Gdtr[2], Idtr[2];
+// Best not let anyone mess with these particular registers...
+ addq $48, %rsp
+// UINT64 Rip;
+ popq (%rax)
+
+// UINT64 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.
+//
+
+ popq %rax
+ # mov %rax, %gs
+ popq %rax
+ # mov %rax, %fs
+ popq %rax
+ mov %rax, %es
+ popq %rax
+ mov %rax, %ds
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ popq 8(%rax)
+ popq %rax
+ mov %rax, %ss
+## The next stuff to restore is the general purpose registers that were pushed
+## using the "push" instruction.
+##
+## The value of RSP as stored in the context record is the application RSP
+## including the 5 entries on the application stack caused by the exception
+## itself. It may have been modified by the debug agent, so we need to
+## determine if we need to relocate the application stack.
+
+ movq 24(%rsp), %rbx # move the potentially modified AppRsp into rbx
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq 24(%rax), %rax
+ cmpq %rax, %rbx
+ je NoAppStackMove
+
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq (%rax), %rcx # RIP
+ movq %rcx, (%rbx)
+
+ movq 8(%rax), %rcx # CS
+ movq %rcx, 8(%rbx)
+
+ movq 16(%rax), %rcx # RFLAGS
+ movq %rcx, 16(%rbx)
+
+ movq 24(%rax), %rcx # RSP
+ movq %rcx, 24(%rbx)
+
+ movq 32(%rax), %rcx # SS
+ movq %rcx, 32(%rbx)
+
+ movq %rbx, %rax # modify the saved AppRsp to the new AppRsp
+ movq %rax, ASM_PFX(AppRsp)(%rip)
+NoAppStackMove:
+ movq ASM_PFX(DebugRsp)(%rip), %rax # restore the DebugRsp on the debug stack
+ # so our "pop" will not cause a stack switch
+ movq %rax, 24(%rsp)
+
+ cmpl $0x068, ASM_PFX(ExceptionNumber)(%rip)
+ jne NoChain
+
+Chain:
+
+// Restore rflags so when we chain, the flags will be exactly as if we were never here.
+// We gin up the stack to do an iretq so we can get ALL the flags.
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq 40(%rax), %rbx
+ pushq %rbx
+ mov %ss, %rax
+ pushq %rax
+ movq %rsp, %rax
+ addq $16, %rax
+ pushq %rax
+ movq ASM_PFX(AppRsp)(%rip), %rax
+ movq 16(%rax), %rbx
+ andq $0xfffffffffffffcff, %rbx # special handling for IF and TF
+ pushq %rbx
+ mov %cs, %rax
+ pushq %rax
+ movq PhonyIretq(%rip), %rax
+ pushq %rax
+ iretq
+PhonyIretq:
+
+// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
+// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
+ popq %rdi
+ popq %rsi
+ popq %rbp
+ popq %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
+
+// Switch back to application stack
+ movq ASM_PFX(AppRsp)(%rip), %rsp
+// Jump to original handler
+ jmp ASM_PFX(OrigVector)
+NoChain:
+// UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
+// UINT64 R8, R9, R10, R11, R12, R13, R14, R15;
+ popq %rdi
+ popq %rsi
+ popq %rbp
+ popq %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
+
+// Switch back to application stack
+ movq ASM_PFX(AppRsp)(%rip), %rsp
+
+// We're outa here...
+ iret