Signed-off-by: rsun3 Reviewed-by: jyao1 git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11664 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			597 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
			
		
		
	
	
			597 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			NASM
		
	
	
	
	
	
;/** @file
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;  Low level x64 routines used by the debug support driver.
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;
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;  Copyright (c) 2007 - 2011, Intel Corporation. All rights reserved.<BR>
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;  This program and the accompanying materials
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;  are licensed and made available under the terms and conditions of the BSD License
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;  which accompanies this distribution.  The full text of the license may be found at
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;  http://opensource.org/licenses/bsd-license.php
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;
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;  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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;  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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;
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;**/
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EXCPT64_DIVIDE_ERROR     EQU    0
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EXCPT64_DEBUG            EQU    1
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EXCPT64_NMI              EQU    2
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EXCPT64_BREAKPOINT       EQU    3
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EXCPT64_OVERFLOW         EQU    4
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EXCPT64_BOUND            EQU    5
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EXCPT64_INVALID_OPCODE   EQU    6
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EXCPT64_DOUBLE_FAULT     EQU    8
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EXCPT64_INVALID_TSS      EQU   10
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EXCPT64_SEG_NOT_PRESENT  EQU   11
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EXCPT64_STACK_FAULT      EQU   12
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EXCPT64_GP_FAULT         EQU   13
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EXCPT64_PAGE_FAULT       EQU   14
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EXCPT64_FP_ERROR         EQU   16
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EXCPT64_ALIGNMENT_CHECK  EQU   17
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EXCPT64_MACHINE_CHECK    EQU   18
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EXCPT64_SIMD             EQU   19
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FXSTOR_FLAG              EQU   01000000h         ; bit cpuid 24 of feature flags
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;; The FXSTOR and FXRSTOR commands are used for saving and restoring the x87,
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;; MMX, SSE, SSE2, etc registers.  The initialization of the debugsupport driver
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;; MUST check the CPUID feature flags to see that these instructions are available
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;; and fail to init if they are not.
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;; fxstor [rdi]
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FXSTOR_RDI               MACRO
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                         db 0fh, 0aeh, 00000111y ; mod = 00, reg/op = 000, r/m = 111 = [rdi]
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ENDM
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;; fxrstor [rsi]
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FXRSTOR_RSI              MACRO
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                         db 0fh, 0aeh, 00001110y ; mod = 00, reg/op = 001, r/m = 110 = [rsi]
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ENDM
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data SEGMENT
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public          OrigVector, InterruptEntryStub, StubSize, CommonIdtEntry, FxStorSupport
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StubSize        dd      InterruptEntryStubEnd - InterruptEntryStub
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AppRsp          dq      1111111111111111h ; ?
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DebugRsp        dq      2222222222222222h ; ?
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ExtraPush       dq      3333333333333333h ; ?
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ExceptData      dq      4444444444444444h ; ?
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Rflags          dq      5555555555555555h ; ?
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OrigVector      dq      6666666666666666h ; ?
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;; The declarations below define the memory region that will be used for the debug stack.
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;; The context record will be built by pushing register values onto this stack.
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;; It is imparitive that alignment be carefully managed, since the FXSTOR and
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;; FXRSTOR instructions will GP fault if their memory operand is not 16 byte aligned.
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;;
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;; The stub will switch stacks from the application stack to the debuger stack
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;; and pushes the exception number.
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;;
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;; Then we building the context record on the stack. Since the stack grows down,
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;; we push the fields of the context record from the back to the front.  There
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;; are 336 bytes of stack used prior allocating the 512 bytes of stack to be
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;; used as the memory buffer for the fxstor instruction. Therefore address of
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;; the buffer used for the FXSTOR instruction is &Eax - 336 - 512, which
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;; must be 16 byte aligned.
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;;
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;; We carefully locate the stack to make this happen.
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;;
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;; For reference, the context structure looks like this:
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;;      struct {
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;;        UINT64            ExceptionData;
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;;        FX_SAVE_STATE_X64 FxSaveState;    // 512 bytes, must be 16 byte aligned
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;;        UINT64            Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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;;        UINT64            Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
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;;        UINT64            RFlags;
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;;        UINT64            Ldtr, Tr;
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;;        UINT64            Gdtr[2], Idtr[2];
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;;        UINT64            Rip;
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;;        UINT64            Gs, Fs, Es, Ds, Cs, Ss;
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;;        UINT64            Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
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;;        UINT64            R8, R9, R10, R11, R12, R13, R14, R15;
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;;      } SYSTEM_CONTEXT_X64;  // 64 bit system context record
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align           16
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DebugStackEnd   db      "DbgStkEnd >>>>>>"      ;; 16 byte long string - must be 16 bytes to preserve alignment
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                dd      1ffch dup (000000000h)  ;; 32K should be enough stack
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                                                ;;   This allocation is coocked to insure
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                                                ;;   that the the buffer for the FXSTORE instruction
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                                                ;;   will be 16 byte aligned also.
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                                                ;;
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ExceptionNumber dq      ?                       ;; first entry will be the vector number pushed by the stub
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DebugStackBegin db      "<<<< DbgStkBegin"      ;; initial debug ESP == DebugStackBegin, set in stub
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data ENDS
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text SEGMENT
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externdef InterruptDistrubutionHub:near
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;------------------------------------------------------------------------------
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; BOOLEAN
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; FxStorSupport (
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;   void
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;   )
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;
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; Abstract: Returns TRUE if FxStor instructions are supported
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;
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FxStorSupport   PROC    PUBLIC
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;
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; cpuid corrupts rbx which must be preserved per the C calling convention
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;
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                push    rbx
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                mov     rax, 1
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                cpuid
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                mov     eax, edx
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                and     rax, FXSTOR_FLAG
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                shr     rax, 24
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                pop     rbx
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                ret
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FxStorSupport   ENDP
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;------------------------------------------------------------------------------
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; void
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; Vect2Desc (
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;   IA32_IDT_GATE_DESCRIPTOR * DestDesc,  // rcx
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;   void (*Vector) (void)   // rdx
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;   )
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;
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; Abstract: Encodes an IDT descriptor with the given physical address
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;
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Vect2Desc       PROC    PUBLIC
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                mov     rax, rdx
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                mov     word ptr [rcx], ax                  ; write bits 15..0 of offset
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                mov     dx, cs
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                mov     word ptr [rcx+2], dx                ; SYS_CODE_SEL from GDT
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                mov     word ptr [rcx+4], 0e00h OR 8000h    ; type = 386 interrupt gate, present
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                shr     rax, 16
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                mov     word ptr [rcx+6], ax                ; write bits 31..16 of offset
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                shr     rax, 16
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                mov     dword ptr [rcx+8], eax              ; write bits 63..32 of offset
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                ret
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Vect2Desc       ENDP
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;------------------------------------------------------------------------------
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; InterruptEntryStub
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;
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; Abstract: This code is not a function, but is a small piece of code that is
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;               copied and fixed up once for each IDT entry that is hooked.
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;
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InterruptEntryStub::
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                push    0                       ; push vector number - will be modified before installed
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                db      0e9h                    ; jump rel32
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                dd      0                       ; fixed up to relative address of CommonIdtEntry
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InterruptEntryStubEnd:
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;------------------------------------------------------------------------------
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; CommonIdtEntry
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;
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; Abstract: This code is not a function, but is the common part for all IDT
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;               vectors.
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;
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CommonIdtEntry::
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;;
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;; At this point, the stub has saved the current application stack esp into AppRsp
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;; and switched stacks to the debug stack, where it pushed the vector number
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;;
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;; The application stack looks like this:
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;;
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;;              ...
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;;              (last application stack entry)
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;;              [16 bytes alignment, do not care it]
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;;              SS from interrupted task
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;;              RSP from interrupted task
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;;              rflags from interrupted task
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;;              CS from interrupted task
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;;              RIP from interrupted task
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;;              Error code <-------------------- Only present for some exeption types
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;;
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;;              Vector Number <----------------- pushed in our IDT Entry
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;;
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;; The stub switched us to the debug stack and pushed the interrupt number.
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;;
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;; Next, construct the context record.  It will be build on the debug stack by
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;; pushing the registers in the correct order so as to create the context structure
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;; on the debug stack.  The context record must be built from the end back to the
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;; beginning because the stack grows down...
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;
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;; For reference, the context record looks like this:
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;;
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;; typedef
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;; struct {
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;;   UINT64            ExceptionData;
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;;   FX_SAVE_STATE_X64 FxSaveState;
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;;   UINT64            Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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;;   UINT64            Cr0, Cr2, Cr3, Cr4, Cr8;
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;;   UINT64            RFlags;
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;;   UINT64            Ldtr, Tr;
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;;   UINT64            Gdtr[2], Idtr[2];
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;;   UINT64            Rip;
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;;   UINT64            Gs, Fs, Es, Ds, Cs, Ss;
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;;   UINT64            Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
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;;   UINT64            R8, R9, R10, R11, R12, R13, R14, R15;
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;; } SYSTEM_CONTEXT_X64;  // 64 bit system context record
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;; NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp
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                push    rax
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                mov     rax, qword ptr [rsp][8]          ; save vector number
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                mov     ExceptionNumber, rax             ; save vector number
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                pop     rax
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                add     rsp, 8                           ; pop vector number
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                mov     AppRsp, rsp                      ; save stack top
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                mov     rsp, offset DebugStackBegin      ; switch to debugger stack
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                sub     rsp, 8                           ; leave space for vector number
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;; UINT64  Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
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;; UINT64  R8, R9, R10, R11, R12, R13, R14, R15;
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                push    r15
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                push    r14
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                push    r13
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                push    r12
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                push    r11
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                push    r10
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                push    r9
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                push    r8
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                push    rax
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                push    rcx
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                push    rdx
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                push    rbx
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                push    rsp
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                push    rbp
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                push    rsi
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                push    rdi
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;; Save interrupt state rflags register...
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                pushfq
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                pop     rax
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                mov     qword ptr Rflags, rax
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;; We need to determine if any extra data was pushed by the exception, and if so, save it
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;; To do this, we check the exception number pushed by the stub, and cache the
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;; result in a variable since we'll need this again.
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                cmp     ExceptionNumber, EXCPT64_DOUBLE_FAULT
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_INVALID_TSS
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_SEG_NOT_PRESENT
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_STACK_FAULT
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_GP_FAULT
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_PAGE_FAULT
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                jz      ExtraPushOne
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                cmp     ExceptionNumber, EXCPT64_ALIGNMENT_CHECK
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                jz      ExtraPushOne
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                mov     ExtraPush, 0
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                mov     ExceptData, 0
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                jmp     ExtraPushDone
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ExtraPushOne:
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                mov     ExtraPush, 1
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;; If there's some extra data, save it also, and modify the saved AppRsp to effectively
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;; pop this value off the application's stack.
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                mov     rax, AppRsp
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                mov     rbx, [rax]
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                mov     ExceptData, rbx
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                add     rax, 8
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                mov     AppRsp, rax
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ExtraPushDone:
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;; The "push" above pushed the debug stack rsp.  Since what we're actually doing
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;; is building the context record on the debug stack, we need to save the pushed
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;; debug RSP, and replace it with the application's last stack entry...
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                mov     rax, [rsp + 24]
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                mov     DebugRsp, rax
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                mov     rax, AppRsp
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                mov     rax, QWORD PTR [rax + 24]
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                ; application stack has ss, rsp, rflags, cs, & rip, so
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                ; last actual application stack entry is saved at offset
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                ; 24 bytes from stack top.
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                mov     [rsp + 24], rax
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;; continue building context record
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;; UINT64  Gs, Fs, Es, Ds, Cs, Ss;  insure high 16 bits of each is zero
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                mov     rax, ss
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                push    rax
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                ; CS from application is one entry back in application stack
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                mov     rax, AppRsp
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                movzx   rax, word ptr [rax + 8]
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                push    rax
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                mov     rax, ds
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                push    rax
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                mov     rax, es
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                push    rax
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                mov     rax, fs
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                push    rax
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                mov     rax, gs
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                push    rax
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;; UINT64  Rip;
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                ; Rip from application is on top of application stack
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                mov     rax, AppRsp
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                push    qword ptr [rax]
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;; UINT64  Gdtr[2], Idtr[2];
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                push    0
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                push    0
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                sidt    fword ptr [rsp]
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                push    0
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                push    0
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                sgdt    fword ptr [rsp]
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;; UINT64  Ldtr, Tr;
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                xor     rax, rax
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                str     ax
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                push    rax
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                sldt    ax
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                push    rax
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;; UINT64  RFlags;
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;; Rflags from application is two entries back in application stack
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                mov     rax, AppRsp
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                push    qword ptr [rax + 16]
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;; UINT64  Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
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;; insure FXSAVE/FXRSTOR is enabled in CR4...
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;; ... while we're at it, make sure DE is also enabled...
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                mov     rax, cr8
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                push    rax
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                mov     rax, cr4
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                or      rax, 208h
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                mov     cr4, rax
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                push    rax
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                mov     rax, cr3
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                push    rax
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                mov     rax, cr2
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                push    rax
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                push    0
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                mov     rax, cr0
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                push    rax
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;; UINT64  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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                mov     rax, dr7
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                push    rax
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;; clear Dr7 while executing debugger itself
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                xor     rax, rax
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                mov     dr7, rax
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                mov     rax, dr6
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                push    rax
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;; insure all status bits in dr6 are clear...
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                xor     rax, rax
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                mov     dr6, rax
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                mov     rax, dr3
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                push    rax
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                mov     rax, dr2
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                push    rax
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                mov     rax, dr1
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                push    rax
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                mov     rax, dr0
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                push    rax
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;; FX_SAVE_STATE_X64 FxSaveState;
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                sub     rsp, 512
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                mov     rdi, rsp
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                ; IMPORTANT!! The debug stack has been carefully constructed to
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                ; insure that rsp and rdi are 16 byte aligned when we get here.
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                ; They MUST be.  If they are not, a GP fault will occur.
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                FXSTOR_RDI
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;; UEFI calling convention for x64 requires that Direction flag in EFLAGs is clear
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                cld
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;; UINT64  ExceptionData;
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                mov     rax, ExceptData
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                push    rax
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; call to C code which will in turn call registered handler
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; pass in the vector number
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                mov     rdx, rsp
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                mov     rcx, ExceptionNumber
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                sub     rsp, 40
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                call    InterruptDistrubutionHub
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                add     rsp, 40
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; restore context...
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;; UINT64  ExceptionData;
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                add     rsp, 8
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;; FX_SAVE_STATE_X64 FxSaveState;
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                mov     rsi, rsp
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                FXRSTOR_RSI
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                add     rsp, 512
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;; UINT64  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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                pop     rax
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                mov     dr0, rax
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                pop     rax
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                mov     dr1, rax
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                pop     rax
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                mov     dr2, rax
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                pop     rax
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                mov     dr3, rax
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;; skip restore of dr6.  We cleared dr6 during the context save.
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                add     rsp, 8
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                pop     rax
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                mov     dr7, rax
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 | 
						|
;; UINT64  Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
 | 
						|
                pop     rax
 | 
						|
                mov     cr0, rax
 | 
						|
                add     rsp, 8
 | 
						|
                pop     rax
 | 
						|
                mov     cr2, rax
 | 
						|
                pop     rax
 | 
						|
                mov     cr3, rax
 | 
						|
                pop     rax
 | 
						|
                mov     cr4, rax
 | 
						|
                pop     rax
 | 
						|
                mov     cr8, rax
 | 
						|
 | 
						|
;; UINT64  RFlags;
 | 
						|
                mov     rax, AppRsp
 | 
						|
                pop     qword ptr [rax + 16]
 | 
						|
 | 
						|
;; 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 [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.
 | 
						|
;;
 | 
						|
 | 
						|
                pop     rax
 | 
						|
                ; mov     gs, rax
 | 
						|
                pop     rax
 | 
						|
                ; mov     fs, rax
 | 
						|
                pop     rax
 | 
						|
                mov     es, rax
 | 
						|
                pop     rax
 | 
						|
                mov     ds, rax
 | 
						|
                mov     rax, AppRsp
 | 
						|
                pop     qword ptr [rax + 8]
 | 
						|
                pop     rax
 | 
						|
                mov     ss, rax
 | 
						|
 | 
						|
;; 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.
 | 
						|
 | 
						|
                mov     rbx, [rsp + 24]  ; move the potentially modified AppRsp into rbx
 | 
						|
                mov     rax, AppRsp
 | 
						|
                mov     rax, QWORD PTR [rax + 24]
 | 
						|
                cmp     rbx, rax
 | 
						|
                je      NoAppStackMove
 | 
						|
 | 
						|
                mov     rax, AppRsp
 | 
						|
                mov     rcx, [rax]       ; RIP
 | 
						|
                mov     [rbx], rcx
 | 
						|
 | 
						|
                mov     rcx, [rax + 8]   ; CS
 | 
						|
                mov     [rbx + 8], rcx
 | 
						|
 | 
						|
                mov     rcx, [rax + 16]  ; RFLAGS
 | 
						|
                mov     [rbx + 16], rcx
 | 
						|
 | 
						|
                mov     rcx, [rax + 24]  ; RSP
 | 
						|
                mov     [rbx + 24], rcx
 | 
						|
 | 
						|
                mov     rcx, [rax + 32]  ; SS
 | 
						|
                mov     [rbx + 32], rcx
 | 
						|
 | 
						|
                mov     rax, rbx         ; modify the saved AppRsp to the new AppRsp
 | 
						|
                mov     AppRsp, rax
 | 
						|
NoAppStackMove:
 | 
						|
                mov     rax, DebugRsp    ; restore the DebugRsp on the debug stack
 | 
						|
                                         ; so our "pop" will not cause a stack switch
 | 
						|
                mov     [rsp + 24], rax
 | 
						|
 | 
						|
                cmp     ExceptionNumber, 068h
 | 
						|
                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.
 | 
						|
                mov     rax, AppRsp
 | 
						|
                mov     rbx, [rax + 40]
 | 
						|
                push    rbx
 | 
						|
                mov     rax, ss
 | 
						|
                push    rax
 | 
						|
                mov     rax, rsp
 | 
						|
                add     rax, 16
 | 
						|
                push    rax
 | 
						|
                mov     rax, AppRsp
 | 
						|
                mov     rbx, [rax + 16]
 | 
						|
                and     rbx, NOT 300h ; special handling for IF and TF
 | 
						|
                push    rbx
 | 
						|
                mov     rax, cs
 | 
						|
                push    rax
 | 
						|
                mov     rax, offset PhonyIretq
 | 
						|
                push    rax
 | 
						|
                iretq
 | 
						|
PhonyIretq:
 | 
						|
 | 
						|
;; UINT64  Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
 | 
						|
;; UINT64  R8, R9, R10, R11, R12, R13, R14, R15;
 | 
						|
                pop     rdi
 | 
						|
                pop     rsi
 | 
						|
                pop     rbp
 | 
						|
                pop     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
 | 
						|
 | 
						|
;; Switch back to application stack
 | 
						|
                mov     rsp, AppRsp
 | 
						|
 | 
						|
;; Jump to original handler
 | 
						|
                jmp     OrigVector
 | 
						|
 | 
						|
NoChain:
 | 
						|
;; UINT64  Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
 | 
						|
;; UINT64  R8, R9, R10, R11, R12, R13, R14, R15;
 | 
						|
                pop     rdi
 | 
						|
                pop     rsi
 | 
						|
                pop     rbp
 | 
						|
                pop     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
 | 
						|
 | 
						|
;; Switch back to application stack
 | 
						|
                mov     rsp, AppRsp
 | 
						|
 | 
						|
;; We're outa here...
 | 
						|
                iretq
 | 
						|
text ENDS
 | 
						|
 | 
						|
END
 | 
						|
 | 
						|
 | 
						|
 |