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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; see the file COPYING.LIB. If
- not, see <http://www.gnu.org/licenses/>. */
- /* 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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