uclibc-ng/libc/sysdeps/linux/sh/crt0.S

/* Startup code for SH & ELF.
   Copyright (C) 1999 Free Software Foundation, Inc.
   Copyright (C) 2001 Hewlett-Packard Australia

   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.  */

/* This is the canonical entry point, usually the first thing in the text
   segment.

	At this entry point, most registers' values are unspecified, except:

   r4		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.
		WARNING: At that stage only static linker is supported. For
		uCLinux we won't bother with r4.

   sp		The stack contains the arguments and environment:
   		0(sp)			argc
		4(sp)			argv[0]
		...
		(4*argc)(sp)		NULL
		(4*(argc+1))(sp)	envp[0]
		...
					NULL
*/

	.text
	.globl _start
	
_start:
	/* Clear the frame pointer since this is the outermost frame.  */
	mov #0, r14

	/* Pop argc off the stack and save a pointer to argv */
	mov.l @r15+,r4
	mov r15, r5

	/* set up the value for the environment pointer
	   r6 = (argc+1)*4+argv
	*/
	mov r4,r6
	add #1,r6
	shll2 r6
	add r5,r6

	/* call main */
	mov.l L_main,r1
	jsr @r1
	nop

	/* should never get here....*/
	mov.l L_abort,r1
	jsr @r1
	nop

	.align	2

L_main:
	.long	__uClibc_main

L_abort:
	.long	abort

	.data