-#/**@file\r
-# Low leve x64 specific debug support functions.\r
-#\r
-# Copyright (c) 2006 - 2009, Intel Corporation\r
-# All rights reserved. This program and the accompanying materials\r
-# are licensed and made available under the terms and conditions of the BSD License\r
-# which accompanies this distribution. The full text of the license may be found at\r
-# http://opensource.org/licenses/bsd-license.php\r
-#\r
-# THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
-# WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
-#\r
-#**/ \r
-\r
-ASM_GLOBAL ASM_PFX(OrigVector)\r
-ASM_GLOBAL ASM_PFX(InterruptEntryStub)\r
-ASM_GLOBAL ASM_PFX(StubSize)\r
-ASM_GLOBAL ASM_PFX(CommonIdtEntry)\r
-ASM_GLOBAL ASM_PFX(FxStorSupport)\r
- \r
-.data \r
-\r
-ASM_PFX(StubSize): .long ASM_PFX(InterruptEntryStubEnd) - ASM_PFX(InterruptEntryStub)\r
-ASM_PFX(AppRsp): .long 0x11111111 # ?\r
- .long 0x11111111 # ?\r
-ASM_PFX(DebugRsp): .long 0x22222222 # ?\r
- .long 0x22222222 # ?\r
-ASM_PFX(ExtraPush): .long 0x33333333 # ?\r
- .long 0x33333333 # ?\r
-ASM_PFX(ExceptData): .long 0x44444444 # ?\r
- .long 0x44444444 # ?\r
-ASM_PFX(Rflags): .long 0x55555555 # ?\r
- .long 0x55555555 # ?\r
-ASM_PFX(OrigVector): .long 0x66666666 # ?\r
- .long 0x66666666 # ?\r
-\r
-## The declarations below define the memory region that will be used for the debug stack.\r
-## The context record will be built by pushing register values onto this stack.\r
-## It is imparitive that alignment be carefully managed, since the FXSTOR and\r
-## FXRSTOR instructions will GP fault if their memory operand is not 16 byte aligned.\r
-##\r
-## The stub will switch stacks from the application stack to the debuger stack\r
-## and pushes the exception number.\r
-##\r
-## Then we building the context record on the stack. Since the stack grows down,\r
-## we push the fields of the context record from the back to the front. There\r
-## are 336 bytes of stack used prior allocating the 512 bytes of stack to be\r
-## used as the memory buffer for the fxstor instruction. Therefore address of\r
-## the buffer used for the FXSTOR instruction is &Eax - 336 - 512, which\r
-## must be 16 byte aligned.\r
-##\r
-## We carefully locate the stack to make this happen.\r
-##\r
-## For reference, the context structure looks like this:\r
-## struct {\r
-## UINT64 ExceptionData;\r
-## FX_SAVE_STATE_X64 FxSaveState; // 512 bytes, must be 16 byte aligned\r
-## UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
-## UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;\r
-## UINT64 RFlags;\r
-## UINT64 Ldtr, Tr;\r
-## UINT64 Gdtr[2], Idtr[2];\r
-## UINT64 Rip;\r
-## UINT64 Gs, Fs, Es, Ds, Cs, Ss;\r
-## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
-## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
-## } SYSTEM_CONTEXT_X64; // 64 bit system context record\r
-\r
-.p2align 4\r
-DebugStackEnd : .ascii "DbgStkEnd >>>>>>" # 16 byte long string - must be 16 bytes to preserve alignment\r
- .fill 0x1ffc, 4, 0x00000000\r
- # 32K should be enough stack\r
- # This allocation is coocked to insure\r
- # that the the buffer for the FXSTORE instruction\r
- # will be 16 byte aligned also.\r
- #\r
-ASM_PFX(ExceptionNumber): .long 0x77777777 # first entry will be the vector number pushed by the stub\r
- .long 0x77777777 # ?\r
-\r
-DebugStackBegin : .ascii "<<<< DbgStkBegin" # initial debug ESP == DebugStackBegin, set in stub\r
- \r
-\r
-.text\r
-\r
-#------------------------------------------------------------------------------\r
-# BOOLEAN\r
-# FxStorSupport (\r
-# void\r
-# )\r
-#\r
-# Abstract: Returns TRUE if FxStor instructions are supported\r
-#\r
-ASM_GLOBAL ASM_PFX(FxStorSupport)\r
-ASM_PFX(FxStorSupport): \r
-#\r
-# cpuid corrupts rbx which must be preserved per the C calling convention\r
-#\r
- pushq %rbx\r
- movq $1, %rax\r
- cpuid\r
- movl %edx, %eax\r
- andq $0x01000000, %rax\r
- shrq $24, %rax\r
- popq %rbx\r
- ret\r
-#------------------------------------------------------------------------------\r
-# void\r
-# Vect2Desc (\r
-# IA32_IDT_GATE_DESCRIPTOR * DestDesc, // rcx\r
-# void (*Vector) (void) // rdx\r
-# )\r
-#\r
-# Abstract: Encodes an IDT descriptor with the given physical address\r
-#\r
-ASM_GLOBAL ASM_PFX(Vect2Desc)\r
-ASM_PFX(Vect2Desc):\r
- movq %rdx, %rax\r
- movw %ax, (%rcx) # write bits 15..0 of offset\r
- movw %cs, %dx\r
- movw %dx, 2(%rcx) # SYS_CODE_SEL from GDT\r
- movw $(0x0e00 | 0x8000), 4(%rcx) # type = 386 interrupt gate, present\r
- shrq $16, %rax\r
- movw %ax, 6(%rcx) # write bits 31..16 of offset\r
- shrq $16, %rax\r
- movl %eax, 8(%rcx) # write bits 63..32 of offset\r
-\r
- ret\r
-\r
-#------------------------------------------------------------------------------\r
-# InterruptEntryStub\r
-#\r
-# Abstract: This code is not a function, but is a small piece of code that is\r
-# copied and fixed up once for each IDT entry that is hooked.\r
-#\r
-ASM_GLOBAL ASM_PFX(InterruptEntryStub)\r
-ASM_PFX(InterruptEntryStub):\r
-\r
- pushq $0 # push vector number - will be modified before installed\r
- jmp ASM_PFX(CommonIdtEntry)\r
- \r
-ASM_GLOBAL ASM_PFX(InterruptEntryStubEnd)\r
-ASM_PFX(InterruptEntryStubEnd):\r
-\r
-#------------------------------------------------------------------------------\r
-# CommonIdtEntry\r
-#\r
-# Abstract: This code is not a function, but is the common part for all IDT\r
-# vectors.\r
-#\r
-ASM_GLOBAL ASM_PFX(CommonIdtEntry)\r
-##\r
-## At this point, the stub has saved the current application stack esp into AppRsp\r
-## and switched stacks to the debug stack, where it pushed the vector number\r
-##\r
-## The application stack looks like this:\r
-##\r
-## ...\r
-## (last application stack entry)\r
-## [16 bytes alignment, do not care it]\r
-## SS from interrupted task\r
-## RSP from interrupted task\r
-## rflags from interrupted task\r
-## CS from interrupted task\r
-## RIP from interrupted task\r
-## Error code <-------------------- Only present for some exeption types\r
-##\r
-## Vector Number <----------------- pushed in our IDT Entry\r
-##\r
-\r
-\r
-## The stub switched us to the debug stack and pushed the interrupt number.\r
-##\r
-## Next, construct the context record. It will be build on the debug stack by\r
-## pushing the registers in the correct order so as to create the context structure\r
-## on the debug stack. The context record must be built from the end back to the\r
-## beginning because the stack grows down...\r
-#\r
-## For reference, the context record looks like this:\r
-##\r
-## typedef\r
-## struct {\r
-## UINT64 ExceptionData;\r
-## FX_SAVE_STATE_X64 FxSaveState;\r
-## UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
-## UINT64 Cr0, Cr2, Cr3, Cr4, Cr8;\r
-## UINT64 RFlags;\r
-## UINT64 Ldtr, Tr;\r
-## UINT64 Gdtr[2], Idtr[2];\r
-## UINT64 Rip;\r
-## UINT64 Gs, Fs, Es, Ds, Cs, Ss;\r
-## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
-## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
-## } SYSTEM_CONTEXT_X64; // 64\r
-ASM_PFX(CommonIdtEntry):\r
-## NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp\r
- pushq %rax\r
- movq (8)(%rsp), %rax # save vector number\r
- movq %rax, ASM_PFX(ExceptionNumber) # save vector number\r
- popq %rax\r
- addq $8, %rsp # pop vector number\r
- movq %rsp, ASM_PFX(AppRsp) # save stack top\r
- movq DebugStackBegin, %rsp # switch to debugger stack\r
- subq $8, %rsp # leave space for vector number\r
-## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
-## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
- pushq %r15\r
- pushq %r14\r
- pushq %r13\r
- pushq %r12\r
- pushq %r11\r
- pushq %r10\r
- pushq %r9\r
- pushq %r8\r
- pushq %rax\r
- pushq %rcx\r
- pushq %rdx\r
- pushq %rbx\r
- pushq %rsp\r
- pushq %rbp\r
- pushq %rsi\r
- pushq %rdi\r
-## Save interrupt state rflags register...\r
- pushfq\r
- popq %rax\r
- movq %rax, ASM_PFX(Rflags)\r
-## We need to determine if any extra data was pushed by the exception, and if so, save it\r
-## To do this, we check the exception number pushed by the stub, and cache the\r
-## result in a variable since we'll need this again.\r
- cmpl $0, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $10, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $11, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $12, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $13, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $14, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- cmpl $17, ASM_PFX(ExceptionNumber)\r
- jz ExtraPushOne\r
- movl $0, ASM_PFX(ExtraPush)\r
- movl $0, ASM_PFX(ExceptData)\r
- jmp ExtraPushDone\r
-ExtraPushOne:\r
- movl $1, ASM_PFX(ExtraPush)\r
-\r
-## If there's some extra data, save it also, and modify the saved AppRsp to effectively\r
-## pop this value off the application's stack.\r
- movq ASM_PFX(AppRsp), %rax \r
- movq (%rax), %rbx\r
- movq %rbx, ASM_PFX(ExceptData)\r
- addq $8, %rax\r
- movq %rax, ASM_PFX(AppRsp)\r
-\r
-ExtraPushDone:\r
-\r
-## The "push" above pushed the debug stack rsp. Since what we're actually doing\r
-## is building the context record on the debug stack, we need to save the pushed\r
-## debug RSP, and replace it with the application's last stack entry...\r
- movq 24(%rsp), %rax\r
- movq %rax, ASM_PFX(DebugRsp)\r
- movq ASM_PFX(AppRsp), %rax \r
- addq $40, %rax\r
- # application stack has ss, rsp, rflags, cs, & rip, so\r
- # last actual application stack entry is 40 bytes\r
- # into the application stack.\r
- movq %rax, 24(%rsp)\r
-\r
-## continue building context record\r
-## UINT64 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero\r
- movq %ss, %rax\r
- pushq %rax\r
- # CS from application is one entry back in application stack\r
- movq ASM_PFX(AppRsp), %rax\r
- movzxw 8(%rax), %rax\r
- pushq %rax\r
-\r
- movq %ds, %rax\r
- pushq %rax\r
- movq %es, %rax\r
- pushq %rax\r
- movq %fs, %rax\r
- pushq %rax\r
- movq %gs, %rax\r
- pushq %rax\r
-## UINT64 Rip;\r
- # Rip from application is on top of application stack\r
- movq ASM_PFX(AppRsp), %rax \r
- pushq (%rax)\r
-## UINT64 Gdtr[2], Idtr[2];\r
- push $0\r
- push $0\r
- sidtq (%rsp)\r
- push $0\r
- push $0\r
- sgdtq (%rsp)\r
-\r
-## UINT64 Ldtr, Tr;\r
- xorq %rax, %rax\r
- str %ax\r
- pushq %rax\r
- sldt %ax\r
- pushq %rax\r
-\r
-## UINT64 RFlags;\r
-## Rflags from application is two entries back in application stack\r
- movq ASM_PFX(AppRsp), %rax \r
- pushq 16(%rax)\r
-## UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;\r
-## insure FXSAVE/FXRSTOR is enabled in CR4...\r
-## ... while we're at it, make sure DE is also enabled...\r
- movq %cr8, %rax\r
- pushq %rax\r
- movq %cr4, %rax\r
- orq $0x208, %rax\r
- movq %rax, %cr4\r
- pushq %rax\r
- movq %cr3, %rax\r
- pushq %rax\r
- movq %cr2, %rax\r
- pushq %rax\r
- push $0\r
- movq %cr0, %rax\r
- pushq %rax\r
-## UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
- movq %dr7, %rax\r
- pushq %rax\r
-## clear Dr7 while executing debugger itself\r
- xorq %rax, %rax\r
- movq %rax, %dr7\r
-\r
- movq %dr6, %rax\r
- pushq %rax\r
-## insure all status bits in dr6 are clear...\r
- xorq %rax, %rax\r
- movq %rax, %dr6\r
-\r
- movq %dr3, %rax\r
- pushq %rax\r
- movq %dr2, %rax\r
- pushq %rax\r
- movq %dr1, %rax\r
- pushq %rax\r
- movq %dr0, %rax\r
- pushq %rax\r
-\r
-## FX_SAVE_STATE_X64 FxSaveState;\r
- subq $512, %rsp\r
- movq %rsp, %rdi\r
- # IMPORTANT!! The debug stack has been carefully constructed to\r
- # insure that rsp and rdi are 16 byte aligned when we get here.\r
- # They MUST be. If they are not, a GP fault will occur.\r
- \r
- # FXSTOR_RDI\r
- fxsave (%rdi)\r
-\r
-## UINT64 ExceptionData;\r
- movq ASM_PFX(ExceptData), %rax\r
- pushq %rax\r
-\r
-# call to C code which will in turn call registered handler\r
-# pass in the vector number\r
- movq %rsp, %rdx\r
- movq ASM_PFX(ExceptionNumber), %rcx \r
- subq $40, %rsp\r
- call ASM_PFX(InterruptDistrubutionHub)\r
- addq $40, %rsp\r
-# restore context...\r
-## UINT64 ExceptionData;\r
- addq $8, %rsp\r
-\r
-## FX_SAVE_STATE_X64 FxSaveState;\r
- movq %rsp, %rsi\r
- \r
- # FXRSTOR_RSI\r
- fxrstor (%rsi)\r
-\r
- addq $512, %rsp\r
-\r
-## UINT64 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;\r
- popq %rax\r
- movq %rax, %dr0\r
- popq %rax\r
- movq %rax, %dr1\r
- popq %rax\r
- movq %rax, %dr2\r
- popq %rax\r
- movq %rax, %dr3\r
-\r
-## skip restore of dr6. We cleared dr6 during the context save.\r
- addq $8, %rsp\r
- popq %rax\r
- movq %rax, %dr7\r
-\r
-## UINT64 Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;\r
- popq %rax\r
- movq %rax, %cr0\r
- addq $8, %rsp\r
- popq %rax\r
- movq %rax, %cr2\r
- popq %rax\r
- movq %rax, %cr3\r
- popq %rax\r
- movq %rax, %cr4\r
- popq %rax\r
- movq %rax, %cr8\r
-## UINT64 RFlags;\r
- movq ASM_PFX(AppRsp), %rax \r
- popq 16(%rax)\r
-## UINT64 Ldtr, Tr;\r
-## UINT64 Gdtr[2], Idtr[2];\r
-## Best not let anyone mess with these particular registers...\r
- addq $48, %rsp\r
-## UINT64 Rip;\r
- popq (%rax)\r
-\r
-## UINT64 Gs, Fs, Es, Ds, Cs, Ss;\r
-## NOTE - modified segment registers could hang the debugger... We\r
-## could attempt to insulate ourselves against this possibility,\r
-## but that poses risks as well.\r
-##\r
-\r
- popq %rax\r
- # movq %rax, %gs\r
- popq %rax\r
- # movq %rax, %fs\r
- popq %rax\r
- movq %rax, %es\r
- popq %rax\r
- movq %rax, %ds\r
- movq ASM_PFX(AppRsp), %rax \r
- popq 8(%rax)\r
- popq %rax\r
- movq %rax, %ss\r
-## The next stuff to restore is the general purpose registers that were pushed\r
-## using the "push" instruction.\r
-##\r
-## The value of RSP as stored in the context record is the application RSP\r
-## including the 5 entries on the application stack caused by the exception\r
-## itself. It may have been modified by the debug agent, so we need to\r
-## determine if we need to relocate the application stack.\r
-\r
- movq 24(%rsp), %rbx # move the potentially modified AppRsp into rbx\r
- movq ASM_PFX(AppRsp), %rax \r
- addq $40, %rax\r
- cmpq %rax, %rbx\r
- je NoAppStackMove\r
-\r
- movq ASM_PFX(AppRsp), %rax \r
- movq (%rax), %rcx # RIP\r
- movq %rcx, (%rbx)\r
-\r
- movq 8(%rax), %rcx # CS\r
- movq %rcx, 8(%rbx)\r
-\r
- movq 16(%rax), %rcx # RFLAGS\r
- movq %rcx, 16(%rbx)\r
-\r
- movq 24(%rax), %rcx # RSP\r
- movq %rcx, 24(%rbx)\r
-\r
- movq 32(%rax), %rcx # SS\r
- movq %rcx, 32(%rbx)\r
-\r
- movq %rbx, %rax # modify the saved AppRsp to the new AppRsp\r
- movq %rax, ASM_PFX(AppRsp)\r
-NoAppStackMove:\r
- movq ASM_PFX(DebugRsp), %rax # restore the DebugRsp on the debug stack\r
- # so our "pop" will not cause a stack switch\r
- movq %rax, 24(%rsp)\r
-\r
- cmpl $0x068, ASM_PFX(ExceptionNumber)\r
- jne NoChain\r
-\r
-Chain:\r
-\r
-## Restore rflags so when we chain, the flags will be exactly as if we were never here.\r
-## We gin up the stack to do an iretq so we can get ALL the flags.\r
- movq ASM_PFX(AppRsp), %rax \r
- movq 40(%rax), %rbx\r
- pushq %rbx\r
- movq %ss, %rax\r
- pushq %rax\r
- movq %rsp, %rax\r
- addq $16, %rax\r
- pushq %rax\r
- movq ASM_PFX(AppRsp), %rax \r
- movq 16(%rax), %rbx\r
- andq $0xfffffffffffffcff, %rbx # special handling for IF and TF\r
- pushq %rbx\r
- movq %cs, %rax\r
- pushq %rax\r
- movq PhonyIretq, %rax \r
- pushq %rax\r
- iretq\r
-PhonyIretq:\r
-\r
-## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
-## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
- popq %rdi\r
- popq %rsi\r
- popq %rbp\r
- popq %rsp\r
- popq %rbx\r
- popq %rdx\r
- popq %rcx\r
- popq %rax\r
- popq %r8\r
- popq %r9\r
- popq %r10\r
- popq %r11\r
- popq %r12\r
- popq %r13\r
- popq %r14\r
- popq %r15\r
-\r
-## Switch back to application stack\r
- movq ASM_PFX(AppRsp), %rsp \r
-## Jump to original handler\r
- jmp ASM_PFX(OrigVector)\r
-NoChain:\r
-## UINT64 Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;\r
-## UINT64 R8, R9, R10, R11, R12, R13, R14, R15;\r
- popq %rdi\r
- popq %rsi\r
- popq %rbp\r
- popq %rsp\r
- popq %rbx\r
- popq %rdx\r
- popq %rcx\r
- popq %rax\r
- popq %r8\r
- popq %r9\r
- popq %r10\r
- popq %r11\r
- popq %r12\r
- popq %r13\r
- popq %r14\r
- popq %r15\r
-\r
-## Switch back to application stack\r
- movq ASM_PFX(AppRsp), %rsp \r
-\r
-## We're outa here...\r
- iret\r
+///**@file
+// Low leve x64 specific debug support functions.
+//
+// Copyright (c) 2006 - 2009, Intel Corporation
+// Portions copyright (c) 2008-2009 Apple Inc. All rights reserved.
+// 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
+ addq $40, %rax
+ # application stack has ss, rsp, rflags, cs, & rip, so
+ # last actual application stack entry is 40 bytes
+ # into the application stack.
+ 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)
+
+// 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
+ addq $40, %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
projects / mirror_edk2.git / blobdiff