[glibc.git] / sysdeps / mips / elf / start.S

/* 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., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#define __ASSEMBLY__ 1
#include <entry.h>
#include <sgidefs.h>
#include <sys/asm.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)
*/
	
	.text
	.globl ENTRY_POINT
	.type ENTRY_POINT,@function
ENTRY_POINT:
#ifdef __PIC__
	SETUP_GPX($0)
	SETUP_GPX64($25,$0)
#else
	PTR_LA $28, _gp		/* Setup GP correctly if we're non-PIC.  */
	move $31, $0
#endif

	PTR_LA $4, main		/* main */
	PTR_L $5, 0($29)		/* argc */
	PTR_ADDIU $6, $29, PTRSIZE	/* argv  */
	
	/* 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 * SZREG
#if _MIPS_SIM == _ABIO32
	PTR_SUBIU $29, 32
#endif
	PTR_LA $7, __libc_csu_init		/* init */
	PTR_LA $8, __libc_csu_fini
#if _MIPS_SIM == _ABIO32
	PTR_S $8, 16($29)		/* fini */
	PTR_S $2, 20($29)		/* rtld_fini */
	PTR_S $29, 24($29)		/* stack_end */
#else
	move $9, $2		/* rtld_fini */
	move $10, $29		/* stack_end */
#endif
	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
Commit	Line	Data
a334319f UD	1	/* Startup code compliant to the ELF Mips ABI.
	2	Copyright (C) 1995, 1997, 2000, 2001, 2002, 2003, 2004
	3	Free Software Foundation, Inc.
	4	This file is part of the GNU C Library.
	5
	6	The GNU C Library is free software; you can redistribute it and/or
	7	modify it under the terms of the GNU Lesser General Public
	8	License as published by the Free Software Foundation; either
	9	version 2.1 of the License, or (at your option) any later version.
	10
	11	In addition to the permissions in the GNU Lesser General Public
	12	License, the Free Software Foundation gives you unlimited
	13	permission to link the compiled version of this file with other
	14	programs, and to distribute those programs without any restriction
	15	coming from the use of this file. (The GNU Lesser General Public
	16	License restrictions do apply in other respects; for example, they
	17	cover modification of the file, and distribution when not linked
	18	into another program.)
	19
	20	Note that people who make modified versions of this file are not
	21	obligated to grant this special exception for their modified
	22	versions; it is their choice whether to do so. The GNU Lesser
	23	General Public License gives permission to release a modified
	24	version without this exception; this exception also makes it
	25	possible to release a modified version which carries forward this
	26	exception.
	27
	28	The GNU C Library is distributed in the hope that it will be useful,
	29	but WITHOUT ANY WARRANTY; without even the implied warranty of
	30	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	31	Lesser General Public License for more details.
	32
	33	You should have received a copy of the GNU Lesser General Public
	34	License along with the GNU C Library; if not, write to the Free
	35	Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
	36	02111-1307 USA. */
	37
	38	#define __ASSEMBLY__ 1
	39	#include <entry.h>
	40	#include <sgidefs.h>
	41	#include <sys/asm.h>
	42
	43	#ifndef ENTRY_POINT
	44	#error ENTRY_POINT needs to be defined for start.S on MIPS/ELF.
	45	#endif
	46
	47	/* This is the canonical entry point, usually the first thing in the text
	48	segment. The SVR4/Mips ABI (pages 3-31, 3-32) says that when the entry
	49	point runs, most registers' values are unspecified, except for:
	50
	51	v0 ($2) Contains a function pointer to be registered with `atexit'.
	52	This is how the dynamic linker arranges to have DT_FINI
	53	functions called for shared libraries that have been loaded
	54	before this code runs.
	55
	56	sp ($29) The stack contains the arguments and environment:
	57	0(%esp) argc
	58	4(%esp) argv[0]
	59	...
	60	(4*argc)(%esp) NULL
	61	(4*(argc+1))(%esp) envp[0]
	62	...
	63	NULL
	64	ra ($31) The return address register is set to zero so that programs
65	that search backword through stack frames recognize the last
66	stack frame.
67	*/
68
69
70	/* We need to call:
71	__libc_start_main (int (main) (int, char , char *), int argc,
72	char *argv, void (init) (void), void (*fini) (void),
73	void (rtld_fini) (void), void stack_end)
74	*/
75
76	.text
77	.globl ENTRY_POINT
78	.type ENTRY_POINT,@function
79	ENTRY_POINT:
80	#ifdef __PIC__
81	SETUP_GPX($0)
82	SETUP_GPX64($25,$0)
83	#else
84	PTR_LA $28, _gp /* Setup GP correctly if we're non-PIC. */
85	move $31, $0
86	#endif
87
88	PTR_LA $4, main /* main */
89	PTR_L $5, 0($29) /* argc */
90	PTR_ADDIU $6, $29, PTRSIZE /* argv */
91
92	/* Allocate space on the stack for seven arguments (o32 only)
93	and make sure the stack is aligned to double words (8 bytes)
94	on o32 and quad words (16 bytes) on n32 and n64. */
95
96	and $29, -2 * SZREG
97	#if _MIPS_SIM == _ABIO32
98	PTR_SUBIU $29, 32
99	#endif
100	PTR_LA $7, __libc_csu_init /* init */
101	PTR_LA $8, __libc_csu_fini
102	#if _MIPS_SIM == _ABIO32
103	PTR_S $8, 16($29) /* fini */
104	PTR_S $2, 20($29) /* rtld_fini */
105	PTR_S $29, 24($29) /* stack_end */
106	#else
107	move $9, $2 /* rtld_fini */
108	move $10, $29 /* stack_end */
109	#endif
110	jal __libc_start_main
111	hlt: b hlt /* Crash if somehow it does return. */
112
113	/* Define a symbol for the first piece of initialized data. */
114	.data
115	.globl __data_start
116	__data_start:
117	.long 0
118	.weak data_start
119	data_start = __data_start