diff options
Diffstat (limited to 'ports/sysdeps/mips/start.S')
| -rw-r--r-- | ports/sysdeps/mips/start.S | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/ports/sysdeps/mips/start.S b/ports/sysdeps/mips/start.S new file mode 100644 index 0000000000..fa0cfe14e0 --- /dev/null +++ b/ports/sysdeps/mips/start.S @@ -0,0 +1,118 @@ +/* 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/>. */ + +#define __ASSEMBLY__ 1 +#include <entry.h> +#include <sgidefs.h> +#include <sys/asm.h> + +#ifndef ENTRY_POINT +#error ENTRY_POINT needs to be defined for start.S on MIPS/ELF. +#endif + +/* 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: + __libc_start_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 ENTRY_POINT + .type ENTRY_POINT,@function +ENTRY_POINT: +#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 (o32 only) + and make sure the stack is aligned to double words (8 bytes) + on o32 and quad words (16 bytes) on n32 and n64. */ + + and $29, -2 * SZREG +#if _MIPS_SIM == _ABIO32 + PTR_SUBIU $29, 32 +#endif + PTR_LA $7, __libc_csu_init /* init */ + PTR_LA $8, __libc_csu_fini +#if _MIPS_SIM == _ABIO32 + 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 __libc_start_main +hlt: b hlt /* Crash if somehow it does return. */ + +/* 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 |