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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
.intel_syntax noprefix
#include "unixasmmacros.inc"
#include "asmconstants.h"
//
// Implementation of CONTEXT_CaptureContext for the Intel x86 platform.
//
// extern void CONTEXT_CaptureContext(LPCONTEXT lpContext);
//
// This function is processor-dependent. It is used by exception handling,
// and is always apply to the current thread.
//
LEAF_ENTRY CONTEXT_CaptureContext, _TEXT
// Store
push eax
push ebx
// The stack will contain the following elements on the top of
// the caller's stack
// [ebx] / esp + 00
// [eax] / esp + 04
// [ret] / esp + 08
// [arg0: lpContext] / esp + 12
mov eax, [esp + 12] // eax will point to lpContext
// Capture INTEGER registers
mov ebx, [esp + 4]
mov [eax + CONTEXT_Eax], ebx
mov ebx, [esp]
mov [eax + CONTEXT_Ebx], ebx
mov [eax + CONTEXT_Ecx], ecx
mov [eax + CONTEXT_Edx], edx
mov [eax + CONTEXT_Esi], esi
mov [eax + CONTEXT_Edi], edi
// Capture CONTROL registers
mov [eax + CONTEXT_Ebp], ebp
lea ebx, [esp + 12]
mov [eax + CONTEXT_Esp], ebx
mov [eax + CONTEXT_ResumeEsp], ebx
mov ebx, [esp + 8]
mov [eax + CONTEXT_Eip], ebx
push cs
xor ebx, ebx
pop bx
mov [eax + CONTEXT_SegCs], ebx
push ss
xor ebx, ebx
pop bx
mov [eax + CONTEXT_SegSs], ebx
pushf
xor ebx, ebx
pop bx
mov [eax + CONTEXT_EFlags], ebx
test BYTE PTR [eax + CONTEXT_ContextFlags], CONTEXT_FLOATING_POINT
je LOCAL_LABEL(Done_CONTEXT_FLOATING_POINT)
// Capture FPU status
fnsave [eax + CONTEXT_FloatSave]
frstor [eax + CONTEXT_FloatSave]
LOCAL_LABEL(Done_CONTEXT_FLOATING_POINT):
test BYTE PTR [eax + CONTEXT_ContextFlags], CONTEXT_EXTENDED_REGISTERS
je LOCAL_LABEL(Done_CONTEXT_EXTENDED_REGISTERS)
movdqu [eax + CONTEXT_Xmm0], xmm0
movdqu [eax + CONTEXT_Xmm1], xmm1
movdqu [eax + CONTEXT_Xmm2], xmm2
movdqu [eax + CONTEXT_Xmm3], xmm3
movdqu [eax + CONTEXT_Xmm4], xmm4
movdqu [eax + CONTEXT_Xmm5], xmm5
movdqu [eax + CONTEXT_Xmm6], xmm6
movdqu [eax + CONTEXT_Xmm7], xmm7
LOCAL_LABEL(Done_CONTEXT_EXTENDED_REGISTERS):
// Restore
pop ebx
pop eax
ret
LEAF_END CONTEXT_CaptureContext, _TEXT
LEAF_ENTRY RtlCaptureContext, _TEXT
push eax
mov eax, [esp + 8]
mov DWORD PTR [eax + CONTEXT_ContextFlags], (CONTEXT_FLOATING_POINT)
pop eax
jmp C_FUNC(CONTEXT_CaptureContext)
LEAF_END RtlCaptureContext, _TEXT
LEAF_ENTRY RtlRestoreContext, _TEXT
mov eax, [esp + 4]
test BYTE PTR [eax + CONTEXT_ContextFlags], CONTEXT_FLOATING_POINT
je LOCAL_LABEL(Done_Restore_CONTEXT_FLOATING_POINT)
frstor [eax + CONTEXT_FloatSave]
LOCAL_LABEL(Done_Restore_CONTEXT_FLOATING_POINT):
test BYTE PTR [eax + CONTEXT_ContextFlags], CONTEXT_EXTENDED_REGISTERS
je LOCAL_LABEL(Done_Restore_CONTEXT_EXTENDED_REGISTERS)
movdqu xmm0, [eax + CONTEXT_Xmm0]
movdqu xmm1, [eax + CONTEXT_Xmm1]
movdqu xmm2, [eax + CONTEXT_Xmm2]
movdqu xmm3, [eax + CONTEXT_Xmm3]
movdqu xmm4, [eax + CONTEXT_Xmm4]
movdqu xmm5, [eax + CONTEXT_Xmm5]
movdqu xmm6, [eax + CONTEXT_Xmm6]
movdqu xmm7, [eax + CONTEXT_Xmm7]
LOCAL_LABEL(Done_Restore_CONTEXT_EXTENDED_REGISTERS):
// Restore Stack
mov esp, [eax + CONTEXT_ResumeEsp]
// Create a minimal frame
push DWORD PTR [eax + CONTEXT_Eip]
// Restore register(s)
mov ebp, [eax + CONTEXT_Ebp]
mov edi, [eax + CONTEXT_Edi]
mov esi, [eax + CONTEXT_Esi]
mov edx, [eax + CONTEXT_Edx]
mov ecx, [eax + CONTEXT_Ecx]
mov ebx, [eax + CONTEXT_Ebx]
mov eax, [eax + CONTEXT_Eax]
// Resume
ret
LEAF_END RtlRestoreContext, _TEXT
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