The GNU assembler (2.24.51.20140918) is failing to build when movw is used on this instruction. Instead use the mov instruction, which matches the other cases of loading segment registers. The error message seen is: AsmFuncs.iii:283: Error: incorrect register `%rax' used with `w' suffix Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Jordan Justen <jordan.l.justen@intel.com> Reviewed-by: Jeff Fan <jeff.fan@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16529 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			552 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			552 lines
		
	
	
		
			21 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| ///**@file
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| // Low leve x64 specific debug support functions.
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| //
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| // Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
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| // Portions copyright (c) 2008 - 2009, Apple Inc. 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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| ASM_GLOBAL ASM_PFX(OrigVector)
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| ASM_GLOBAL ASM_PFX(InterruptEntryStub)
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| ASM_GLOBAL ASM_PFX(StubSize)
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| ASM_GLOBAL ASM_PFX(CommonIdtEntry)
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| ASM_GLOBAL ASM_PFX(FxStorSupport)
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| 
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| .data
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| 
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| ASM_PFX(StubSize):         .long   ASM_PFX(InterruptEntryStubEnd) - ASM_PFX(InterruptEntryStub)
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| ASM_PFX(AppRsp):           .long   0x11111111 # ?
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|                            .long   0x11111111 # ?
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| ASM_PFX(DebugRsp):         .long   0x22222222 # ?
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|                            .long   0x22222222 # ?
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| ASM_PFX(ExtraPush):        .long   0x33333333 # ?
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|                            .long   0x33333333 # ?
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| ASM_PFX(ExceptData):       .long   0x44444444 # ?
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|                            .long   0x44444444 # ?
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| ASM_PFX(Rflags):           .long   0x55555555 # ?
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|                            .long   0x55555555 # ?
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| ASM_PFX(OrigVector):       .long   0x66666666 # ?
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|                            .long   0x66666666 # ?
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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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| .p2align 4
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| DebugStackEnd : .ascii     "DbgStkEnd >>>>>>"    # 16 byte long string - must be 16 bytes to preserve alignment
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|                 .fill 0x1ffc, 4, 0x00000000
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|                                                  # 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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| ASM_PFX(ExceptionNumber):  .long   0x77777777    # first entry will be the vector number pushed by the stub
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|                            .long   0x77777777    # ?
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| 
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| DebugStackBegin : .ascii    "<<<< DbgStkBegin"   # initial debug ESP == DebugStackBegin, set in stub
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| 
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| 
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| .text
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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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| ASM_GLOBAL ASM_PFX(FxStorSupport)
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| ASM_PFX(FxStorSupport):
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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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|                 pushq   %rbx
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|                 movq    $1, %rax
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|                 cpuid
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|                 movl    %edx, %eax
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|                 andq    $0x01000000, %rax
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|                 shrq    $24, %rax
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|                 popq    %rbx
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|                 ret
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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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| ASM_GLOBAL ASM_PFX(Vect2Desc)
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| ASM_PFX(Vect2Desc):
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|                 movq    %rdx, %rax
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|                 movw    %ax, (%rcx)                  # write bits 15..0 of offset
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|                 movw    %cs, %dx
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|                 movw    %dx, 2(%rcx)                 # SYS_CODE_SEL from GDT
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|                 movw    $(0x0e00 | 0x8000), 4(%rcx)  # type = 386 interrupt gate, present
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|                 shrq    $16, %rax
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|                 movw    %ax, 6(%rcx)                 # write bits 31..16 of offset
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|                 shrq    $16, %rax
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|                 movl    %eax, 8(%rcx)                # write bits 63..32 of offset
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| 
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|                 ret
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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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| ASM_GLOBAL ASM_PFX(InterruptEntryStub)
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| ASM_PFX(InterruptEntryStub):
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| 
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|                 pushq  $0                       # push vector number - will be modified before installed
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|                 jmp     ASM_PFX(CommonIdtEntry)
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| 
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| ASM_GLOBAL ASM_PFX(InterruptEntryStubEnd)
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| ASM_PFX(InterruptEntryStubEnd):
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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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| ASM_GLOBAL ASM_PFX(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
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| ASM_PFX(CommonIdtEntry):
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| // NOTE: we save rsp here to prevent compiler put rip reference cause error AppRsp
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|                 pushq   %rax
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|                 movq    (8)(%rsp), %rax                  # save vector number
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|                 movq    %rax, ASM_PFX(ExceptionNumber)(%rip)   # save vector number
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|                 popq    %rax
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|                 addq    $8, %rsp                         # pop vector number
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|                 movq    %rsp, ASM_PFX(AppRsp)(%rip)      # save stack top
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|                 movq    DebugStackBegin(%rip), %rsp      # switch to debugger stack
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|                 subq    $8, %rsp                         # 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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|                 pushq    %r15
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|                 pushq    %r14
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|                 pushq    %r13
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|                 pushq    %r12
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|                 pushq    %r11
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|                 pushq    %r10
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|                 pushq    %r9
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|                 pushq    %r8
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|                 pushq    %rax
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|                 pushq    %rcx
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|                 pushq    %rdx
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|                 pushq    %rbx
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|                 pushq    %rsp
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|                 pushq    %rbp
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|                 pushq    %rsi
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|                 pushq    %rdi
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| // Save interrupt state rflags register...
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|                 pushfq
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|                 popq    %rax
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|                 movq    %rax, ASM_PFX(Rflags)(%rip)
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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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|                 cmpl    $0, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $10, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $11, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $12, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $13, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $14, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 cmpl    $17, ASM_PFX(ExceptionNumber)(%rip)
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|                 jz      ExtraPushOne
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|                 movl    $0, ASM_PFX(ExtraPush)(%rip)
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|                 movl    $0, ASM_PFX(ExceptData)(%rip)
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|                 jmp     ExtraPushDone
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| ExtraPushOne:
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|                 movl  $1, ASM_PFX(ExtraPush)(%rip)
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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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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 movq    (%rax), %rbx
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|                 movq    %rbx, ASM_PFX(ExceptData)(%rip)
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|                 addq    $8, %rax
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|                 movq    %rax, ASM_PFX(AppRsp)(%rip)
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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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|                 movq    24(%rsp), %rax
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|                 movq    %rax, ASM_PFX(DebugRsp)(%rip)
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 movq    24(%rax), %rax
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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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|                 movq    %rax, 24(%rsp)
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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     %ss, %rax
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|                 pushq   %rax
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|                 # CS from application is one entry back in application stack
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 movzxw  8(%rax), %rax
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|                 pushq   %rax
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| 
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|                 mov     %ds, %rax
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|                 pushq   %rax
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|                 mov     %es, %rax
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|                 pushq   %rax
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|                 mov     %fs, %rax
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|                 pushq   %rax
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|                 mov     %gs, %rax
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|                 pushq   %rax
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| // UINT64  Rip;
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|                 # Rip from application is on top of application stack
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 pushq   (%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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|                 sidtq   (%rsp)
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|                 push    $0
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|                 push    $0
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|                 sgdtq   (%rsp)
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| 
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| // UINT64  Ldtr, Tr;
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|                 xorq    %rax, %rax
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|                 str     %ax
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|                 pushq   %rax
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|                 sldt    %ax
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|                 pushq   %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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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 pushq   16(%rax)
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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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|                 movq    %cr8, %rax
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|                 pushq   %rax
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|                 movq    %cr4, %rax
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|                 orq     $0x208, %rax
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|                 movq    %rax, %cr4
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|                 pushq   %rax
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|                 movq    %cr3, %rax
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|                 pushq   %rax
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|                 movq    %cr2, %rax
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|                 pushq   %rax
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|                 push    $0
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|                 movq    %cr0, %rax
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|                 pushq   %rax
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| // UINT64  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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|                 movq    %dr7, %rax
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|                 pushq   %rax
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| // clear Dr7 while executing debugger itself
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|                 xorq    %rax, %rax
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|                 movq    %rax, %dr7
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| 
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|                 movq    %dr6, %rax
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|                 pushq   %rax
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| // insure all status bits in dr6 are clear...
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|                 xorq    %rax, %rax
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|                 movq    %rax, %dr6
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| 
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|                 movq    %dr3, %rax
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|                 pushq   %rax
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|                 movq    %dr2, %rax
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|                 pushq   %rax
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|                 movq    %dr1, %rax
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|                 pushq   %rax
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|                 movq    %dr0, %rax
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|                 pushq   %rax
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| 
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| // FX_SAVE_STATE_X64 FxSaveState;
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|                 subq    $512, %rsp
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|                 movq    %rsp, %rdi
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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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| 
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|                 #     FXSTOR_RDI
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|                 fxsave      (%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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|                 movq    ASM_PFX(ExceptData)(%rip),  %rax
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|                 pushq   %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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|                 movq    %rsp, %rdx
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|                 movq    ASM_PFX(ExceptionNumber)(%rip), %rcx
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|                 subq    $40, %rsp
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|                 call    ASM_PFX(InterruptDistrubutionHub)
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|                 addq    $40, %rsp
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| // restore context...
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| // UINT64  ExceptionData;
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|                 addq    $8, %rsp
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| 
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| // FX_SAVE_STATE_X64 FxSaveState;
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|                 movq    %rsp, %rsi
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| 
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|                 #    FXRSTOR_RSI
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|                 fxrstor     (%rsi)
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| 
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|                 addq    $512, %rsp
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| 
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| // UINT64  Dr0, Dr1, Dr2, Dr3, Dr6, Dr7;
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|                 popq    %rax
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|                 movq    %rax, %dr0
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|                 popq    %rax
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|                 movq    %rax, %dr1
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|                 popq    %rax
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|                 movq    %rax, %dr2
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|                 popq    %rax
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|                 movq    %rax, %dr3
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| 
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| // skip restore of dr6.  We cleared dr6 during the context save.
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|                 addq    $8, %rsp
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|                 popq    %rax
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|                 movq    %rax, %dr7
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| 
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| // UINT64  Cr0, Cr1, Cr2, Cr3, Cr4, Cr8;
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|                 popq    %rax
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|                 movq    %rax, %cr0
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|                 addq    $8, %rsp
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|                 popq    %rax
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|                 movq    %rax, %cr2
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|                 popq    %rax
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|                 movq    %rax, %cr3
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|                 popq    %rax
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|                 movq    %rax, %cr4
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|                 popq    %rax
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|                 movq    %rax, %cr8
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| // UINT64  RFlags;
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 popq    16(%rax)
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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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|                 addq    $48, %rsp
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| // UINT64  Rip;
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|                 popq    (%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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|                 popq    %rax
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|                 # mov     %rax, %gs
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|                 popq    %rax
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|                 # mov     %rax, %fs
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|                 popq    %rax
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|                 mov     %rax, %es
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|                 popq    %rax
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|                 mov     %rax, %ds
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 popq    8(%rax)
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|                 popq    %rax
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|                 mov     %rax, %ss
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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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|                 movq    24(%rsp), %rbx  # move the potentially modified AppRsp into rbx
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 movq    24(%rax), %rax
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|                 cmpq    %rax, %rbx
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|                 je      NoAppStackMove
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| 
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|                 movq    ASM_PFX(AppRsp)(%rip), %rax
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|                 movq    (%rax), %rcx     # RIP
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|                 movq    %rcx, (%rbx)
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| 
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|                 movq    8(%rax), %rcx    # CS
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|                 movq    %rcx, 8(%rbx)
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| 
 | |
|                 movq    16(%rax), %rcx   # RFLAGS
 | |
|                 movq    %rcx, 16(%rbx)
 | |
| 
 | |
|                 movq    24(%rax), %rcx   # RSP
 | |
|                 movq    %rcx, 24(%rbx)
 | |
| 
 | |
|                 movq    32(%rax), %rcx   # SS
 | |
|                 movq    %rcx, 32(%rbx)
 | |
| 
 | |
|                 movq    %rbx, %rax       # modify the saved AppRsp to the new AppRsp
 | |
|                 movq    %rax, ASM_PFX(AppRsp)(%rip)
 | |
| NoAppStackMove:
 | |
|                 movq    ASM_PFX(DebugRsp)(%rip), %rax   # restore the DebugRsp on the debug stack
 | |
|                                          # so our "pop" will not cause a stack switch
 | |
|                 movq    %rax, 24(%rsp)
 | |
| 
 | |
|                 cmpl    $0x068, ASM_PFX(ExceptionNumber)(%rip)
 | |
|                 jne     NoChain
 | |
| 
 | |
| Chain:
 | |
| 
 | |
| // Restore rflags so when we chain, the flags will be exactly as if we were never here.
 | |
| // We gin up the stack to do an iretq so we can get ALL the flags.
 | |
|                 movq    ASM_PFX(AppRsp)(%rip), %rax
 | |
|                 movq    40(%rax), %rbx
 | |
|                 pushq   %rbx
 | |
|                 mov     %ss, %rax
 | |
|                 pushq   %rax
 | |
|                 movq    %rsp, %rax
 | |
|                 addq    $16, %rax
 | |
|                 pushq   %rax
 | |
|                 movq    ASM_PFX(AppRsp)(%rip), %rax
 | |
|                 movq    16(%rax), %rbx
 | |
|                 andq    $0xfffffffffffffcff, %rbx  # special handling for IF and TF
 | |
|                 pushq   %rbx
 | |
|                 mov     %cs, %rax
 | |
|                 pushq   %rax
 | |
|                 movq    PhonyIretq(%rip), %rax
 | |
|                 pushq   %rax
 | |
|                 iretq
 | |
| PhonyIretq:
 | |
| 
 | |
| // UINT64  Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
 | |
| // UINT64  R8, R9, R10, R11, R12, R13, R14, R15;
 | |
|                 popq    %rdi
 | |
|                 popq    %rsi
 | |
|                 popq    %rbp
 | |
|                 popq    %rsp
 | |
|                 popq    %rbx
 | |
|                 popq    %rdx
 | |
|                 popq    %rcx
 | |
|                 popq    %rax
 | |
|                 popq    %r8
 | |
|                 popq    %r9
 | |
|                 popq    %r10
 | |
|                 popq    %r11
 | |
|                 popq    %r12
 | |
|                 popq    %r13
 | |
|                 popq    %r14
 | |
|                 popq    %r15
 | |
| 
 | |
| // Switch back to application stack
 | |
|                 movq    ASM_PFX(AppRsp)(%rip), %rsp
 | |
| // Jump to original handler
 | |
|                 jmp     ASM_PFX(OrigVector)
 | |
| NoChain:
 | |
| // UINT64  Rdi, Rsi, Rbp, Rsp, Rbx, Rdx, Rcx, Rax;
 | |
| // UINT64  R8, R9, R10, R11, R12, R13, R14, R15;
 | |
|                 popq    %rdi
 | |
|                 popq    %rsi
 | |
|                 popq    %rbp
 | |
|                 popq    %rsp
 | |
|                 popq    %rbx
 | |
|                 popq    %rdx
 | |
|                 popq    %rcx
 | |
|                 popq    %rax
 | |
|                 popq    %r8
 | |
|                 popq    %r9
 | |
|                 popq    %r10
 | |
|                 popq    %r11
 | |
|                 popq    %r12
 | |
|                 popq    %r13
 | |
|                 popq    %r14
 | |
|                 popq    %r15
 | |
| 
 | |
| // Switch back to application stack
 | |
|                 movq    ASM_PFX(AppRsp)(%rip), %rsp
 | |
| 
 | |
| // We're outa here...
 | |
|                 iret
 |