/* 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