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Diffstat (limited to 'ports/sysdeps/am33/elf/start.S')
| -rw-r--r-- | ports/sysdeps/am33/elf/start.S | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/ports/sysdeps/am33/elf/start.S b/ports/sysdeps/am33/elf/start.S new file mode 100644 index 0000000000..518e75e478 --- /dev/null +++ b/ports/sysdeps/am33/elf/start.S @@ -0,0 +1,80 @@ +/* Startup code compliant to the ELF MN10300 ABI. + Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc. + Contributed by Alexandre Oliva <aoliva@redhat.com> + Based on ../../i386/elf/start.S. + 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. + + 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/>. */ + +/* This is the canonical entry point, usually the first thing in the text + segment. The SVR4/i386 ABI (pages 3-31, 3-32) says that when the entry + point runs, most registers' values are unspecified, except for: + + a0 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 The stack contains the arguments and environment: + (4,sp) argc + (8,sp) argv[0] + ... + (4*(argc+1),sp) NULL + (4*(argc+2),sp) envp[0] + ... + NULL +*/ + +#include "bp-sym.h" + + .text + .globl _start + .type _start,@function +_start: + /* Extract the arguments as encoded on the stack and set up + the arguments for `main': argc, argv. envp will be determined + later in __libc_start_main. */ + mov sp,a3 + add -32,sp + + mov a3,(28,sp) /* stack_end. */ + mov d0,(24,sp) /* rtld_fini. */ + mov _fini, d3 + mov d3,(20,sp) /* fini. */ + mov _init, d2 + mov d2,(16,sp) /* init. */ + inc4 a3 + mov a3,(12,sp) /* argv. */ + + /* Set the initial frame pointer as 0, so that the bottom of + the stack is clearly marked. */ + mov 0,a3 + + mov (32,sp), d1 /* argc. */ + mov BP_SYM (main), d0 /* main. */ + + /* Call the user's main function, and exit with its value. + But let the libc call main. */ + call BP_SYM (__libc_start_main),[],0 + + call BP_SYM (abort),[],0 /* Crash if somehow `exit' 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 |