glibc/sysdeps/alpha/elf/start.S
1996-09-07 04:10:03 +00:00

103 lines
2.6 KiB
ArmAsm

/* Startup code for Alpha/ELF.
Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc.
Contributed by Richard Henderson <rth@tamu.edu>
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <sysdep.h>
.text
.align 3
.globl _start
.ent _start, 0
_start:
.frame fp, 0, zero
mov zero, fp
br gp, 1f
1: ldgp gp, 0(gp)
.prologue 1
/* Save v0. When starting a binary via the dynamic linker, s0
contains the address of the shared library termination function,
which we will register below with atexit() to be called by exit().
If we are statically linked, this will be NULL. */
mov v0, s0
/* Do essential libc initialization (sp points to argc, argv, and envp) */
jsr ra, __libc_init_first
ldgp gp, 0(ra)
/* Now that we have the proper stack frame, register library termination
function, if there is any: */
beq s0, 1f
mov s0, a0
jsr ra, atexit
ldgp gp, 0(ra)
1:
/* Extract the arguments and environment as encoded on the stack. */
ldl a0, 0(sp) /* get argc */
lda a1, 8(sp) /* get argv */
s8addq a0, a1, a2 /* get envp */
addq a2, 8, a2
stq a2, _environ
mov a0, s0 /* tuck them away */
mov a1, s1
mov a2, s2
/* Call _init, the entry point to our own .init section. */
jsr ra, _init
ldgp gp, 0(ra)
/* Register our .fini section with atexit. */
lda a0, _fini
jsr ra, atexit
ldgp gp, 0(ra)
/* Call the user's main and exit with its return value. */
mov s0, a0
mov s1, a1
mov s2, a2
jsr ra, main
ldgp gp, 0(ra)
mov v0, a0
jsr ra, exit
/* Die very horribly if exit returns. Call_pal hlt is callable from
kernel mode only; this will result in an illegal instruction trap. */
call_pal 0
.end _start
/* For ECOFF backwards compatibility. */
weak_alias(_start, __start)
/* Define a symbol for the first piece of initialized data. */
.data
.globl __data_start
__data_start:
.long 0
#ifdef __ELF__
.size __data_start, 4
.type __data_start, @object
#endif
weak_alias(__data_start, data_start)