/* Startup code compliant to the ELF m68k ABI. Copyright (C) 1996, 1997, 1998, 2001 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. 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. */ /* This is the canonical entry point, usually the first thing in the text segment. The SVR4/m68k ABI says that when the entry point runs, most registers' values are unspecified, except for: %a1 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: 0(%sp) argc 4(%sp) argv[0] ... (4*argc)(%sp) NULL (4*(argc+1))(%sp) envp[0] ... NULL */ .text .globl _start .type _start,@function _start: /* Clear the frame pointer. The ABI suggests this be done, to mark the outermost frame obviously. */ sub.l %fp, %fp /* 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. */ move.l (%sp)+, %d0 /* Pop the argument count. */ move.l %sp, %a0 /* The argument vector starts just at the current stack top. */ /* Provide the highest stack address to the user code (for stacks which grow downward). */ pea (%sp) pea (%a1) /* Push address of the shared library termination function. */ /* Push the address of our own entry points to `.fini' and `.init'. */ pea _fini pea _init pea (%a0) /* Push second argument: argv. */ move.l %d0, -(%sp) /* Push first argument: argc. */ pea main /* Call the user's main function, and exit with its value. But let the libc call main. */ jbsr __libc_start_main illegal /* 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