42 lines
1.3 KiB
ArmAsm
42 lines
1.3 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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* x64/syscall.S
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* Function for performing system calls.
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*/
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# x86_64 system call conventions:
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# interrupt 128
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# system call number: %rax
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# parameters: %rdi, %rsi, %rdx, %rcx, %r8, %r9
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# return value: %rax, %rdx
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# return errno: %rcx
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# clobbered: %rdi, %rsi, %r8, %r9, %r10, %r11
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# preserved: %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15
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.global asm_syscall
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asm_syscall: /* syscall num in %rax. */
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push %rbp
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mov %rsp, %rbp
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int $0x80
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test %ecx, %ecx
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jz 1f
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mov %fs:0, %rsi
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mov %ecx, errno@tpoff(%rsi)
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1:
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pop %rbp
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ret
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.size asm_syscall, .-asm_syscall
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