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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| 
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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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| 
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| FXSTOR_FLAG              EQU   01000000h         ; bit cpuid 24 of feature flags
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| 
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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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| 
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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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| 
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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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| 
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| data SEGMENT
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| 
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| public          OrigVector, InterruptEntryStub, StubSize, CommonIdtEntry, FxStorSupport
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| 
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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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| 
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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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| 
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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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| 
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| DebugStackBegin db      "<<<< DbgStkBegin"      ;; initial debug ESP == DebugStackBegin, set in stub
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| 
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| data ENDS
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| 
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| text SEGMENT
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| 
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| externdef InterruptDistrubutionHub:near
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| 
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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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| ;
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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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| ;------------------------------------------------------------------------------
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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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| 
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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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| 
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|                 ret
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| 
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| Vect2Desc       ENDP
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| 
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| 
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| 
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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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| 
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| ExtraPushDone:
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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| ;; UINT64  ExceptionData;
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|                 mov     rax, ExceptData
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|                 push    rax
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| 
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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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| 
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| ; restore context...
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| ;; UINT64  ExceptionData;
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|                 add     rsp, 8
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| 
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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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| 
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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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| 
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| ;; UINT64  Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
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|                 pop     rax
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|                 mov     cr0, rax
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|                 add     rsp, 8
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|                 pop     rax
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|                 mov     cr2, rax
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|                 pop     rax
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|                 mov     cr3, rax
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|                 pop     rax
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|                 mov     cr4, rax
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|                 pop     rax
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|                 mov     cr8, rax
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| 
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| ;; UINT64  RFlags;
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|                 mov     rax, AppRsp
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|                 pop     qword ptr [rax + 16]
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| 
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| ;; UINT64  Ldtr, Tr;
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| ;; UINT64  Gdtr[2], Idtr[2];
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| ;; Best not let anyone mess with these particular registers...
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|                 add     rsp, 48
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| 
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| ;; UINT64  Rip;
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|                 pop     qword ptr [rax]
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| 
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| ;; UINT64  Gs, Fs, Es, Ds, Cs, Ss;
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| ;; NOTE - modified segment registers could hang the debugger...  We
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| ;;        could attempt to insulate ourselves against this possibility,
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| ;;        but that poses risks as well.
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| ;;
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| 
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|                 pop     rax
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|                 ; mov     gs, rax
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|                 pop     rax
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|                 ; mov     fs, rax
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|                 pop     rax
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|                 mov     es, rax
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|                 pop     rax
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|                 mov     ds, rax
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|                 mov     rax, AppRsp
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|                 pop     qword ptr [rax + 8]
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|                 pop     rax
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|                 mov     ss, rax
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| 
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| ;; The next stuff to restore is the general purpose registers that were pushed
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| ;; using the "push" instruction.
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| ;;
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| ;; The value of RSP as stored in the context record is the application RSP
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| ;; including the 5 entries on the application stack caused by the exception
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| ;; itself. It may have been modified by the debug agent, so we need to
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| ;; determine if we need to relocate the application stack.
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| 
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|                 mov     rbx, [rsp + 24]  ; move the potentially modified AppRsp into rbx
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|                 mov     rax, AppRsp
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|                 mov     rax, QWORD PTR [rax + 24]
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|                 cmp     rbx, rax
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|                 je      NoAppStackMove
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| 
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|                 mov     rax, AppRsp
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|                 mov     rcx, [rax]       ; RIP
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|                 mov     [rbx], rcx
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| 
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|                 mov     rcx, [rax + 8]   ; CS
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|                 mov     [rbx + 8], rcx
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| 
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|                 mov     rcx, [rax + 16]  ; RFLAGS
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|                 mov     [rbx + 16], rcx
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| 
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|                 mov     rcx, [rax + 24]  ; RSP
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|                 mov     [rbx + 24], rcx
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| 
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|                 mov     rcx, [rax + 32]  ; SS
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|                 mov     [rbx + 32], rcx
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| 
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|                 mov     rax, rbx         ; modify the saved AppRsp to the new AppRsp
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|                 mov     AppRsp, rax
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| NoAppStackMove:
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|                 mov     rax, DebugRsp    ; restore the DebugRsp on the debug stack
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|                                          ; 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
 | |
| 
 | |
| 
 | |
| 
 |