diff options
Diffstat (limited to 'libc/sysdeps/linux/nios2/crt1.S')
| -rw-r--r-- | libc/sysdeps/linux/nios2/crt1.S | 147 |
1 files changed, 93 insertions, 54 deletions
diff --git a/libc/sysdeps/linux/nios2/crt1.S b/libc/sysdeps/linux/nios2/crt1.S index c178452ae..e13d59599 100644 --- a/libc/sysdeps/linux/nios2/crt1.S +++ b/libc/sysdeps/linux/nios2/crt1.S @@ -1,20 +1,40 @@ -/* - * libc/sysdeps/linux/nios2/crt0.S -- entry point for linux/nios2 - * - * Copyright (C) 2004,05,06 Microtronix Datacom Ltd - * - * This file is subject to the terms and conditions of the GNU Lesser - * General Public License. See the file COPYING.LIB in the main - * directory of this archive for more details. - * - * Written by Wentao Xu <wentao@microtronix.com> - * Updated by Thomas Chou <thomas@wytron.com.tw> for crt1.S - * - */ +/* Startup code for Nios II + Copyright (C) 1995-2016 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/>. */ #include <features.h> #include <asm/unistd.h> -#define TRAP_ID_SYSCALL 0 .global _start .type _start,@function @@ -27,45 +47,64 @@ .type main,@function .type __uClibc_main,@function .text - .balign 4 + _start: - nop - br 0f -0: - /* load gp */ - movhi gp, %hiadj(_gp) - addi gp, gp, %lo(_gp) - - /* load main, argc, argv from stack */ - movhi r4, %hi(main) - ori r4, r4, %lo(main) /* main */ - ldw r5, 0(sp) /* argc */ - ldw r6, 4(sp) /* argv */ - - /* load the 4th arg */ - movhi r7, %hi(_init) - ori r7, r7, %lo(_init) - - /* Allocate space on the stack for 6-7th arg, reuse 5th space */ - addi sp,sp,-8 - /* push 5-7th args on stack */ - movhi r8, %hi(_fini) - ori r8, r8, %lo(_fini) - stw r8, 0(sp) - - stw r2, 4(sp) /* rtld_fini */ - stw sp, 8(sp) /* stack_end */ - - /* call uClibc_main, shouldn't return */ -#ifdef __PIC__ - /* just pray 16 bit offset is enough */ - br __uClibc_main -#else - call __uClibc_main -#endif + /* Set up the global pointer. */ + movhi gp, %hiadj(_gp) + addi gp, gp, %lo(_gp) + + /* Save the stack pointer. */ + mov r2, sp + + /* Create room on the stack for the fini, rtld_fini and stack_end args + to __uClibc_main. */ + subi sp, sp, 12 + + /* Push stack_end */ + stw r2, 8(sp) + + /* Push rtld_fini */ + stw r4, 4(sp) + + /* Set up the GOT pointer. */ + nextpc r22 +1: movhi r2, %hiadj(_gp_got - 1b) + addi r2, r2, %lo(_gp_got - 1b) + add r22, r22, r2 + + /* r6 == argv */ + addi r6, sp, 16 + + /* r5 == argc */ + ldw r5, 12(sp) + + /* r4 == main */ + movhi r4, %call_hiadj(main) + addi r4, r4, %call_lo(main) + add r4, r4, r22 + ldw r4, 0(r4) + + /* fp == 0 */ + mov fp, zero + + /* Let the libc call main and exit with its return code. */ + movhi r2, %call_hiadj(__uClibc_main) + addi r2, r2, %call_lo(__uClibc_main) + add r2, r2, r22 + ldw r2, 0(r2) + callr r2 + + /* should never get here....*/ + movhi r2, %call_hiadj(abort) + addi r2, r2, %call_lo(abort) + add r2, r2, r22 + ldw r2, 0(r2) + callr r2 - /* crash in the event of return */ -__exit: - movui r2, TRAP_ID_SYSCALL - movui r3, __NR_exit - trap +/* 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 |