/* Startup code compliant to the ELF Mips ABI. Copyright (C) 1995, 1997, 2000, 2001, 2002, 2003, 2004 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 <sys/regdef.h> #include <sys/asm.h> #include <features.h> /* This is the canonical entry point, usually the first thing in the text segment. The SVR4/Mips ABI (pages 3-31, 3-32) says that when the entry point runs, most registers' values are unspecified, except for: v0 ($2) 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. sp ($29) The stack contains the arguments and environment: 0(%esp) argc 4(%esp) argv[0] ... (4*argc)(%esp) NULL (4*(argc+1))(%esp) envp[0] ... NULL ra ($31) The return address register is set to zero so that programs that search backword through stack frames recognize the last stack frame. */ /* We need to call: __uClibc_main (int (*main) (int, char **, char **), int argc, char **argv, void (*init) (void), void (*fini) (void), void (*rtld_fini) (void), void *stack_end) */ .text .globl __start .type __start,@function .type _init,@function .type _fini,@function #ifndef __UCLIBC_CTOR_DTOR__ .weak _init .weak _fini #endif .type main,@function .type __uClibc_main,@function .ent __start __start: #ifdef __PIC__ SETUP_GPX($0) SETUP_GPX64($25,$0) #else PTR_LA $28, _gp /* Setup GP correctly if we're non-PIC. */ move $31, $0 #endif PTR_LA $4, main /* main */ PTR_L $5, 0($29) /* argc */ PTR_ADDIU $6, $29, PTRSIZE /* argv */ /* Allocate space on the stack for seven arguments and * make sure the stack is aligned to double words (8 bytes) */ and $29, -2 * SZREG #if _MIPS_SIM == _MIPS_SIM_ABI32 PTR_SUBIU $29, 32 #endif PTR_LA $7, _init /* init */ PTR_LA $8, _fini #if _MIPS_SIM == _MIPS_SIM_ABI32 PTR_S $8, 16($29) /* fini */ PTR_S $2, 20($29) /* rtld_fini */ PTR_S $29, 24($29) /* stack_end */ #else move $9, $2 /* rtld_fini */ move $10, $29 /* stack_end */ #endif jal __uClibc_main hlt: /* Crash if somehow `__uClibc_main' returns anyway. */ b hlt .size __start,.-__start .end __start /* 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