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authorJoseph Myers <joseph@codesourcery.com>2012-07-01 13:06:41 +0000
committerJoseph Myers <joseph@codesourcery.com>2012-07-01 13:06:41 +0000
commite64ac02c24b43659048622714afdc92fedf561fa (patch)
tree37162878b72d302de351788bec4c9360c9d55f1d /ports/sysdeps/mips/start.S
parenta20c2b3c87aebc7d4b090c622d36480263b80042 (diff)
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Move all files into ports/ subdirectory in preparation for merge with glibc glibc-2.16-ports-before-merge
Diffstat (limited to 'ports/sysdeps/mips/start.S')
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1 files changed, 118 insertions, 0 deletions
diff --git a/ports/sysdeps/mips/start.S b/ports/sysdeps/mips/start.S
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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, see
+   <http://www.gnu.org/licenses/>.  */
+
+#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