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/* Copyright (C) 1995, 1996, 1997, 1998, 2001, 2002, 2005
Free Software Foundation, Inc.
Copyright (C) 2010 Embecosm Limited
Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
Contributor Joern Rennecke <joern.rennecke@embecosm.com>
With other contributions from the OpenCores community.
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. */
/* Stick in a dummy reference to main(), so that if an application
* is linking when the main() function is in a static library (.a)
* we can be sure that main() actually gets linked in */
.type main,%function
/* This is the canonical entry point, usually the first thing in the text
segment.
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
*/
#include <features.h>
.text
.globl _start
.type _start,%function
.global _start
_start:
#ifdef __PIC__
/* Obtain a pointer to .got in r16 */
l.jal .LPC0
#ifndef __OR1K_NODELAY__
l.nop
#endif
.LPC0:
l.movhi r16, gotpchi(_GLOBAL_OFFSET_TABLE_+(.-.LPC0))
l.ori r16, r16, gotpclo(_GLOBAL_OFFSET_TABLE_+(.-.LPC0))
l.add r16, r16, r9
#endif
/* Push stack limit onto the stack */
/* Provides highest stack address to user code (as stack grows
* downwards
* This is the seventh argument to __uClibc_main and thus needs to
* be passed on the stack
*/
l.sw -4(r1),r1
/* Take values for argc and argv off the stack.
* These will be passed as arguments two and three to __uClibc_main
* and thus go in registers r4 and r5, respectively
*/
l.lwz r4,0(r1)
l.addi r5,r1,4
#ifdef __PIC__
l.lwz r3,got(main)(r16)
#else
l.movhi r3,hi(main)
l.ori r3,r3,lo(main)
#endif
/* Put the constructor and destructor initialization as args four and
five into r6 and r7 */
#ifdef __PIC__
l.lwz r6, got(_init)(r16)
l.lwz r7, got(_fini)(r16)
#else
l.movhi r6,hi(_init)
l.ori r6,r6,lo(_init)
l.movhi r7,hi(_fini)
l.ori r7,r7,lo(_fini)
#endif
/* rtld_fini = NULL */
l.movhi r8, 0
/* Adjust stack to account for a total of 7 args (i.e. the last one is
on the stack. */
l.addi r1,r1,-4
/* Clear the frame pointer and link register since this is the
* outermost frame.
*/
l.add r2,r0,r0
l.add r9,r0,r0
/* Let the libc call main and exit with its return code. */
#ifdef __PIC__
l.j plt(__uClibc_main)
#else
l.j __uClibc_main
#endif
l.nop
/* 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
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