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sortix--sortix/libc/x64/crt0.S
2014-12-28 20:18:58 +01:00

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1.8 KiB
ArmAsm

/*******************************************************************************
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012, 2014.
This file is part of the Sortix C Library.
The Sortix C Library is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or (at your
option) any later version.
The Sortix C Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
x64/crt0.S
Implement the _start symbol at which execution begins which performs the
task of initializing the standard library and executing the main function.
*******************************************************************************/
.section .text
.global _start
.global __start
.type _start, @function
.type __start, @function
_start:
__start:
# Set up end of the stack frame linked list.
xorl %ebp, %ebp
pushq %rbp # rip=0
pushq %rbp # rbp=0
movq %rsp, %rbp
movq %rcx, environ # envp
# Initialize the standard library.
subq $8, %rsp
pushq %rsi
pushq %rdi
pushq %rcx
call initialize_standard_library
# Run the global constructors.
call _init
# Run main
popq %rdx # Note! envp is now %rdx (previously %rcx)
popq %rdi
popq %rsi
addq $8, %rsp
call main
# Terminate the process with main's exit code.
movl %eax, %edi
call exit
.size _start, .-_start
.size __start, .-__start