fpc/rtl/linux/mips/cprt0.as

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/* Startup code compliant to the ELF Mips ABI.
Copyright (C) 1995, 1997, 2000, 2001, 2002, 2003, 2004
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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
In addition to the permissions in the GNU Lesser General Public
License, the Free Software Foundation gives you unlimited
permission to link the compiled version of this file with other
programs, and to distribute those programs without any restriction
coming from the use of this file. (The GNU Lesser General Public
License restrictions do apply in other respects; for example, they
cover modification of the file, and distribution when not linked
into another program.)
Note that people who make modified versions of this file are not
obligated to grant this special exception for their modified
versions; it is their choice whether to do so. The GNU Lesser
General Public License gives permission to release a modified
version without this exception; this exception also makes it
possible to release a modified version which carries forward this
exception.
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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA. */
/* 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)
*/
.text
.align 2
.globl __libc_csu_init
.type __libc_csu_init, @function
__libc_csu_init:
.set nomips16
.weak __libc_csu_init
.ent __libc_csu_init
.frame $sp,0,$ra
.mask 0x00000000,0
.fmask 0x00000000,0
.set noreorder
.set nomacro
jr $31
nop
.set macro
.set reorder
.end __libc_csu_init
.size __libc_csu_init, .-__libc_csu_init
.align 2
.globl __libc_csu_fini
.type __libc_csu_fini, @function
__libc_csu_fini:
.set nomips16
.weak __libc_csu_fini
.ent __libc_csu_fini
.frame $sp,0,$ra
.mask 0x00000000,0
.fmask 0x00000000,0
.set noreorder
.set nomacro
jr $31
nop
.set macro
.set reorder
.end __libc_csu_fini
.size __libc_csu_fini, .-__libc_csu_fini
.align 2
.globl main
.globl __start
.type __start,@function
__start:
.globl _start
.type _start,@function
_start:
.ent _start
.set noreorder
move $0, $31
bal 10f
nop
10:
.cpload $31
move $31, $0
.set reorder
/* Setup GP correctly if we're non-PIC. */
la $28,_gp
lui $4, %hi(main_stub) /* main */
addiu $4,$4,%lo(main_stub)
lw $5, 0($29) /* argc */
addiu $6, $29, 4 /* argv */
/* store argc */
lw $t0,0($29)
lui $t1,%hi(operatingsystem_parameter_argc)
sw $t0,%lo(operatingsystem_parameter_argc)($t1)
/* store argv */
addiu $t1,$29,4
lui $t2,%hi(operatingsystem_parameter_argv)
sw $t1,%lo(operatingsystem_parameter_argv)($t2)
/* store envp */
addiu $t2,$t0,1
sll $t2,$t2,0x2
addu $t2,$t2,$t1
lui $t3,%hi(operatingsystem_parameter_envp)
sw $t2,%lo(operatingsystem_parameter_envp)($t3)
/* Allocate space on the stack for seven arguments (o32 only)
and make sure the stack is aligned to double words (8 bytes)
on o32 and quad words (16 bytes) on n32 and n64. */
and $29, -2 * 4
subu $29, 32
lw $7,%got(__libc_csu_init)($gp) /* init */
lw $8,%got(__libc_csu_fini)($gp) /* fini */
sw $8, 16($29) /* fini */
sw $2, 20($29) /* rtld_fini */
sw $29, 24($29) /* stack_end */
lw $t9,%got(__libc_start_main)($gp)
jalr $t9
.end _start
.size _start, . - _start
.globl main_stub
.type main_stub,@function
main_stub:
/* load fp */
move $s8,$sp
/* set __stkptr value to $s8 */
lui $v0,%hi(__stkptr)
sw $s8,%lo(__stkptr)($v0)
lui $v0,%hi(__fpc_ret_sp)
sw $sp,%lo(__fpc_ret_sp)($v0)
lui $v0,%hi(__fpc_ret_ra)
sw $ra,%lo(__fpc_ret_ra)($v0)
lui $v0,%hi(main)
addiu $t9,$v0,%lo(main)
jr $t9
nop
.size main_stub,.-main_stub
.globl _haltproc
.ent _haltproc
.type _haltproc,@function
_haltproc:
lui $v0,%hi(__fpc_ret_sp)
lw $sp,%lo(__fpc_ret_sp)($v0)
lui $v0,%hi(__fpc_ret_ra)
lw $ra,%lo(__fpc_ret_ra)($v0)
/* $a0 contains exitcode, we need to move it to $v0,
as it would be at return of C main unction. */
move $v0,$a0
jr $ra
nop
hlt:
b hlt
.end _haltproc
.size _haltproc,.-_haltproc
/* 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
.comm __stkptr,4
.comm __dl_fini,4
.comm __fpc_ret_sp,4
.comm __fpc_ret_ra,4
.comm operatingsystem_parameter_envp,4
.comm operatingsystem_parameter_argc,4
.comm operatingsystem_parameter_argv,4
/* Also define _IO_stdin_used as it is used to */
/* distinguish different libc version */
.section .rodata
.globl _IO_stdin_used
_IO_stdin_used:
.long 0x20001