mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-19 11:30:06 +00:00
98 lines
3.0 KiB
ArmAsm
98 lines
3.0 KiB
ArmAsm
/* Startup code compliant to the ELF Mips ABI.
|
|
Copyright (C) 1995, 1997, 2000, 2001 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#define __ASSEMBLY__ 1
|
|
#include <entry.h>
|
|
|
|
#ifndef ENTRY_POINT
|
|
#error ENTRY_POINT needs to be defined for start.S on MIPS/ELF.
|
|
#endif
|
|
|
|
/* This is the canonical entry point, usually the first thing in the text
|
|
segment. The SVR4/Mips ABI (pages 3-31, 3-32) says that when the entry
|
|
point runs, most registers' values are unspecified, except for:
|
|
|
|
v0 ($2) Contains a function pointer to be registered with `atexit'.
|
|
This is how the dynamic linker arranges to have DT_FINI
|
|
functions called for shared libraries that have been loaded
|
|
before this code runs.
|
|
|
|
sp ($29) The stack contains the arguments and environment:
|
|
0(%esp) argc
|
|
4(%esp) argv[0]
|
|
...
|
|
(4*argc)(%esp) NULL
|
|
(4*(argc+1))(%esp) envp[0]
|
|
...
|
|
NULL
|
|
ra ($31) The return address register is set to zero so that programs
|
|
that search backword through stack frames recognize the last
|
|
stack frame.
|
|
*/
|
|
|
|
|
|
/* We need to call:
|
|
__libc_start_main (int (*main) (int, char **, char **), int argc,
|
|
char **argv, void (*init) (void), void (*fini) (void),
|
|
void (*rtld_fini) (void), void *stack_end)
|
|
*/
|
|
#ifdef __PIC__
|
|
/* A macro to (re)initialize gp. We can get the run time address of 0f in
|
|
ra ($31) by blezal instruction. In this early phase, we can't save gp
|
|
in stack and .cprestore doesn't work properly. So we set gp by using
|
|
this macro. */
|
|
#define SET_GP \
|
|
.set noreorder; \
|
|
bltzal $0,0f; \
|
|
nop; \
|
|
0: .cpload $31; \
|
|
.set reorder;
|
|
#endif
|
|
|
|
.text
|
|
.globl ENTRY_POINT
|
|
ENTRY_POINT:
|
|
#ifdef __PIC__
|
|
SET_GP
|
|
#endif
|
|
move $31, $0
|
|
|
|
la $4, main /* main */
|
|
lw $5, 0($29) /* argc */
|
|
addu $6, $29, 4 /* argv */
|
|
/* Allocate space on the stack for seven arguments and make sure
|
|
the stack is aligned to double words (8 bytes). */
|
|
and $29, 0xfffffff8
|
|
subu $29, 32
|
|
la $7, _init /* init */
|
|
la $8, _fini
|
|
sw $8, 16($29) /* fini */
|
|
sw $2, 20($29) /* rtld_fini */
|
|
sw $29, 24($29) /* stack_end */
|
|
jal __libc_start_main
|
|
hlt: b hlt /* Crash if somehow it does return. */
|
|
|
|
/* Define a symbol for the first piece of initialized data. */
|
|
.data
|
|
.globl __data_start
|
|
__data_start:
|
|
.long 0
|
|
.weak data_start
|
|
data_start = __data_start
|