47 lines
1.2 KiB
ArmAsm
47 lines
1.2 KiB
ArmAsm
/*
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* Copyright (c) 2018 William Pitcock <nenolod@dereferenced.org>
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* This software is provided 'as is' and without any warranty, express or
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* implied. In no event shall the authors be liable for any damages arising
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* from the use of this software.
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*/
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#include "defs.h"
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.globl __setcontext;
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__setcontext:
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/* load address of the ucontext structure */
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movl 4(%esp), %eax
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/* set up the FS segment register */
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movl OFFSET_REG_FS(%eax), %ecx
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movw %cx, %fs
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/* fetch the new EIP */
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movl OFFSET_REG_EIP(%eax), %ecx
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/* set up the new stack pointer */
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movl OFFSET_REG_ESP(%eax), %esp
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/* push the return address onto the stack */
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pushl %ecx
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/* set all of the registers */
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movl OFFSET_REG_EBX(%eax), %ebx
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movl OFFSET_REG_ECX(%eax), %ecx
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movl OFFSET_REG_EDX(%eax), %edx
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movl OFFSET_REG_EBP(%eax), %ebp
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movl OFFSET_REG_EDI(%eax), %edi
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movl OFFSET_REG_ESI(%eax), %esi
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movl OFFSET_REG_EAX(%eax), %eax
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ret
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.weak setcontext;
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setcontext = __setcontext;
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