56 lines
1.6 KiB
ArmAsm
56 lines
1.6 KiB
ArmAsm
/*
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* Copyright (c) 2013, 2014 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and 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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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* x86/syscall.S
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* Function for performing system calls.
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*/
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# i386 system call conventions:
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# interrupt 128
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# system call number: %eax
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# parameters: %ebx, %ecx, %edx, %edi, %esi
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# return value: %eax, %edx
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# return errno: %ecx
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# clobbered: %ebx, %edi, %esi
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# preserved: %ebp, %esp
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.section .text
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.global asm_syscall
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asm_syscall: /* syscall num in %eax. */
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push %ebp
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mov %esp, %ebp
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push %ebx
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push %edi
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push %esi
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# 0 (%ebp) # saved_ebp
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# 4 (%ebp) # return_eip
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mov 8 (%ebp), %ebx # param_word1
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mov 12(%ebp), %ecx # param_word2
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mov 16(%ebp), %edx # param_word3
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mov 20(%ebp), %edi # param_word4
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mov 24(%ebp), %esi # param_word5
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int $0x80
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test %ecx, %ecx # ret_errno & ret_errno
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jz 1f # if ( !(ret_errno & ret_errno) )
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mov %gs:0, %ebx
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mov %ecx, errno@ntpoff(%ebx)
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1:
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pop %esi
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pop %edi
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pop %ebx
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pop %ebp
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ret
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.size asm_syscall, .-asm_syscall
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