X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=blobdiff_plain;f=MdeModulePkg%2FUniversal%2FDebugSupportDxe%2FIa32%2FAsmFuncs.asm;fp=MdeModulePkg%2FUniversal%2FDebugSupportDxe%2FIa32%2FAsmFuncs.asm;h=28a43cfe637cc950d1689eee8ae7a376252e924c;hp=0000000000000000000000000000000000000000;hb=c1f23d63363d36947e76df61320bdd2e5e233946;hpb=00c4901b895c285722a3a11dd9d0e659d84f8951 diff --git a/MdeModulePkg/Universal/DebugSupportDxe/Ia32/AsmFuncs.asm b/MdeModulePkg/Universal/DebugSupportDxe/Ia32/AsmFuncs.asm new file mode 100644 index 0000000000..28a43cfe63 --- /dev/null +++ b/MdeModulePkg/Universal/DebugSupportDxe/Ia32/AsmFuncs.asm @@ -0,0 +1,548 @@ +;****************************************************************************** +;* +;* Copyright (c) 2006, Intel Corporation +;* 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. +;* +;****************************************************************************** + +.586p +.MODEL FLAT, C + +EXCPT32_DIVIDE_ERROR EQU 0 +EXCPT32_DEBUG EQU 1 +EXCPT32_NMI EQU 2 +EXCPT32_BREAKPOINT EQU 3 +EXCPT32_OVERFLOW EQU 4 +EXCPT32_BOUND EQU 5 +EXCPT32_INVALID_OPCODE EQU 6 +EXCPT32_DOUBLE_FAULT EQU 8 +EXCPT32_INVALID_TSS EQU 10 +EXCPT32_SEG_NOT_PRESENT EQU 11 +EXCPT32_STACK_FAULT EQU 12 +EXCPT32_GP_FAULT EQU 13 +EXCPT32_PAGE_FAULT EQU 14 +EXCPT32_FP_ERROR EQU 16 +EXCPT32_ALIGNMENT_CHECK EQU 17 +EXCPT32_MACHINE_CHECK EQU 18 +EXCPT32_SIMD EQU 19 + +FXSTOR_FLAG EQU 01000000h ; bit cpuid 24 of feature flags + +;; The FXSTOR and FXRSTOR commands are used for saving and restoring the x87, +;; MMX, SSE, SSE2, etc registers. The initialization of the debugsupport driver +;; MUST check the CPUID feature flags to see that these instructions are available +;; and fail to init if they are not. + +;; fxstor [edi] +FXSTOR_EDI MACRO + db 0fh, 0aeh, 00000111y ; mod = 00, reg/op = 000, r/m = 111 = [edi] +ENDM + +;; fxrstor [esi] +FXRSTOR_ESI MACRO + db 0fh, 0aeh, 00001110y ; mod = 00, reg/op = 001, r/m = 110 = [esi] +ENDM +.DATA + +public OrigVector, InterruptEntryStub, StubSize, CommonIdtEntry, FxStorSupport + +StubSize dd InterruptEntryStubEnd - InterruptEntryStub +AppEsp dd 11111111h ; ? +DebugEsp dd 22222222h ; ? +ExtraPush dd 33333333h ; ? +ExceptData dd 44444444h ; ? +Eflags dd 55555555h ; ? +OrigVector dd 66666666h ; ? + +;; 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 132 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 - 132 - 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 { +;; UINT32 ExceptionData; +;; FX_SAVE_STATE_IA32 FxSaveState; // 512 bytes, must be 16 byte aligned +;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7; +;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4; +;; UINT32 EFlags; +;; UINT32 Ldtr, Tr; +;; UINT32 Gdtr[2], Idtr[2]; +;; UINT32 Eip; +;; UINT32 Gs, Fs, Es, Ds, Cs, Ss; +;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax; +;; } SYSTEM_CONTEXT_IA32; // 32 bit system context record + + +align 16 +DebugStackEnd db "DbgStkEnd >>>>>>" ;; 16 byte long string - must be 16 bytes to preserve alignment + dd 1ffdh dup (000000000h) ;; 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. + ;; +ExceptionNumber dd ? ;; first entry will be the vector number pushed by the stub + +DebugStackBegin db "<<<< DbgStkBegin" ;; initial debug ESP == DebugStackBegin, set in stub + +.CODE + +externdef InterruptDistrubutionHub:near + +;------------------------------------------------------------------------------ +; BOOLEAN +; FxStorSupport ( +; void +; ) +; +; Abstract: Returns TRUE if FxStor instructions are supported +; +FxStorSupport PROC C PUBLIC + +; +; cpuid corrupts ebx which must be preserved per the C calling convention +; + push ebx + mov eax, 1 + cpuid + mov eax, edx + and eax, FXSTOR_FLAG + shr eax, 24 + pop ebx + ret +FxStorSupport ENDP + + +;------------------------------------------------------------------------------ +; DESCRIPTOR * +; GetIdtr ( +; void +; ) +; +; Abstract: Returns physical address of IDTR +; +GetIdtr PROC C PUBLIC + LOCAL IdtrBuf:FWORD + + sidt IdtrBuf + mov eax, DWORD PTR IdtrBuf + 2 + ret +GetIdtr ENDP + + +;------------------------------------------------------------------------------ +; BOOLEAN +; WriteInterruptFlag ( +; BOOLEAN NewState +; ) +; +; Abstract: Programs interrupt flag to the requested state and returns previous +; state. +; +WriteInterruptFlag PROC C PUBLIC State:DWORD + + pushfd + pop eax + and eax, 200h + shr eax, 9 + mov ecx, State + .IF cl == 0 + cli + .ELSE + sti + .ENDIF + ret + +WriteInterruptFlag ENDP + + + +;------------------------------------------------------------------------------ +; void +; Vect2Desc ( +; DESCRIPTOR * DestDesc, +; void (*Vector) (void) +; ) +; +; Abstract: Encodes an IDT descriptor with the given physical address +; +Vect2Desc PROC C PUBLIC DestPtr:DWORD, Vector:DWORD + + mov eax, Vector + mov ecx, DestPtr + mov word ptr [ecx], ax ; write bits 15..0 of offset + mov dx, cs + mov word ptr [ecx+2], dx ; SYS_CODE_SEL from GDT + mov word ptr [ecx+4], 0e00h OR 8000h ; type = 386 interrupt gate, present + shr eax, 16 + mov word ptr [ecx+6], ax ; write bits 31..16 of offset + + ret + +Vect2Desc ENDP + + + +;------------------------------------------------------------------------------ +; 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. +; +InterruptEntryStub:: + mov AppEsp, esp ; save stack top + mov esp, offset DebugStackBegin ; switch to debugger stack + push 0 ; push vector number - will be modified before installed + db 0e9h ; jump rel32 + dd 0 ; fixed up to relative address of CommonIdtEntry +InterruptEntryStubEnd: + + + +;------------------------------------------------------------------------------ +; CommonIdtEntry +; +; Abstract: This code is not a function, but is the common part for all IDT +; vectors. +; +CommonIdtEntry:: +;; +;; At this point, the stub has saved the current application stack esp into AppEsp +;; and switched stacks to the debug stack, where it pushed the vector number +;; +;; The application stack looks like this: +;; +;; ... +;; (last application stack entry) +;; eflags from interrupted task +;; CS from interrupted task +;; EIP from interrupted task +;; Error code <-------------------- Only present for some exeption types +;; +;; + + +;; 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 { +;; UINT32 ExceptionData; +;; FX_SAVE_STATE_IA32 FxSaveState; +;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7; +;; UINT32 Cr0, Cr2, Cr3, Cr4; +;; UINT32 EFlags; +;; UINT32 Ldtr, Tr; +;; UINT32 Gdtr[2], Idtr[2]; +;; UINT32 Eip; +;; UINT32 Gs, Fs, Es, Ds, Cs, Ss; +;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax; +;; } SYSTEM_CONTEXT_IA32; // 32 bit system context record + +;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax; + pushad + +;; Save interrupt state eflags register... + pushfd + pop eax + mov dword ptr Eflags, eax + +;; 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. + .IF ExceptionNumber == EXCPT32_DOUBLE_FAULT + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_INVALID_TSS + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_SEG_NOT_PRESENT + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_STACK_FAULT + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_GP_FAULT + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_PAGE_FAULT + mov ExtraPush, 1 + .ELSEIF ExceptionNumber == EXCPT32_ALIGNMENT_CHECK + mov ExtraPush, 1 + .ELSE + mov ExtraPush, 0 + .ENDIF + +;; If there's some extra data, save it also, and modify the saved AppEsp to effectively +;; pop this value off the application's stack. + .IF ExtraPush == 1 + mov eax, AppEsp + mov ebx, [eax] + mov ExceptData, ebx + add eax, 4 + mov AppEsp, eax + .ELSE + mov ExceptData, 0 + .ENDIF + +;; The "pushad" above pushed the debug stack esp. Since what we're actually doing +;; is building the context record on the debug stack, we need to save the pushed +;; debug ESP, and replace it with the application's last stack entry... + mov eax, [esp + 12] + mov DebugEsp, eax + mov eax, AppEsp + add eax, 12 + ; application stack has eflags, cs, & eip, so + ; last actual application stack entry is + ; 12 bytes into the application stack. + mov [esp + 12], eax + +;; continue building context record +;; UINT32 Gs, Fs, Es, Ds, Cs, Ss; insure high 16 bits of each is zero + mov eax, ss + push eax + + ; CS from application is one entry back in application stack + mov eax, AppEsp + movzx eax, word ptr [eax + 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; + ; Eip from application is on top of application stack + mov eax, AppEsp + push dword ptr [eax] + +;; UINT32 Gdtr[2], Idtr[2]; + push 0 + push 0 + sidt fword ptr [esp] + push 0 + push 0 + sgdt fword ptr [esp] + +;; UINT32 Ldtr, Tr; + xor eax, eax + str ax + push eax + sldt ax + push eax + +;; UINT32 EFlags; +;; Eflags from application is two entries back in application stack + mov eax, AppEsp + push dword ptr [eax + 8] + +;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4; +;; insure FXSAVE/FXRSTOR is enabled in CR4... +;; ... while we're at it, make sure DE is also enabled... + mov eax, cr4 + or eax, 208h + mov cr4, eax + push eax + mov eax, cr3 + push eax + mov eax, cr2 + push eax + push 0 + mov eax, cr0 + push eax + +;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7; + mov eax, dr7 + push eax +;; clear Dr7 while executing debugger itself + xor eax, eax + mov dr7, eax + + mov eax, dr6 + push eax +;; insure all status bits in dr6 are clear... + xor eax, eax + mov dr6, 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 + ; IMPORTANT!! The debug stack has been carefully constructed to + ; insure that esp and edi are 16 byte aligned when we get here. + ; They MUST be. If they are not, a GP fault will occur. + FXSTOR_EDI + +;; UINT32 ExceptionData; + mov eax, ExceptData + push eax + +; call to C code which will in turn call registered handler +; pass in the vector number + mov eax, esp + push eax + mov eax, ExceptionNumber + push eax + call InterruptDistrubutionHub + add esp, 8 + +; restore context... +;; UINT32 ExceptionData; + add esp, 4 + +;; FX_SAVE_STATE_IA32 FxSaveState; + mov esi, esp + FXRSTOR_ESI + add esp, 512 + +;; UINT32 Dr0, Dr1, Dr2, Dr3, Dr6, Dr7; + pop eax + mov dr0, eax + pop eax + mov dr1, eax + pop eax + mov dr2, eax + pop eax + mov dr3, eax +;; skip restore of dr6. We cleared dr6 during the context save. + add esp, 4 + pop eax + mov dr7, eax + +;; UINT32 Cr0, Cr1, Cr2, Cr3, Cr4; + pop eax + mov cr0, eax + add esp, 4 + pop eax + mov cr2, eax + pop eax + mov cr3, eax + pop eax + mov cr4, eax + +;; UINT32 EFlags; + mov eax, AppEsp + pop dword ptr [eax + 8] + +;; 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 [eax] + +;; UINT32 SegGs, SegFs, SegEs, SegDs, SegCs, SegSs; +;; 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 [eax + 4] + pop ss + +;; The next stuff to restore is the general purpose registers that were pushed +;; using the "pushad" instruction. +;; +;; The value of ESP as stored in the context record is the application ESP +;; including the 3 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. + + mov ebx, [esp + 12] ; move the potentially modified AppEsp into ebx + mov eax, AppEsp + add eax, 12 + cmp ebx, eax + je NoAppStackMove + + mov eax, AppEsp + mov ecx, [eax] ; EIP + mov [ebx], ecx + + mov ecx, [eax + 4] ; CS + mov [ebx + 4], ecx + + mov ecx, [eax + 8] ; EFLAGS + mov [ebx + 8], ecx + + mov eax, ebx ; modify the saved AppEsp to the new AppEsp + mov AppEsp, eax +NoAppStackMove: + mov eax, DebugEsp ; restore the DebugEsp on the debug stack + ; so our "popad" will not cause a stack switch + mov [esp + 12], eax + + cmp ExceptionNumber, 068h + jne NoChain + +Chain: + +;; Restore eflags so when we chain, the flags will be exactly as if we were never here. +;; We gin up the stack to do an iretd so we can get ALL the flags. + mov eax, AppEsp + mov ebx, [eax + 8] + and ebx, NOT 300h ; special handling for IF and TF + push ebx + push cs + push PhonyIretd + iretd +PhonyIretd: + +;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax; + popad + +;; Switch back to application stack + mov esp, AppEsp + +;; Jump to original handler + jmp OrigVector + +NoChain: +;; UINT32 Edi, Esi, Ebp, Esp, Ebx, Edx, Ecx, Eax; + popad + +;; Switch back to application stack + mov esp, AppEsp + +;; We're outa here... + iretd +END + + +