mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 13:00:06 +00:00
121 lines
4.0 KiB
ArmAsm
121 lines
4.0 KiB
ArmAsm
/* Startup code compliant to the ELF m68k ABI.
|
|
Copyright (C) 1996-2016 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/>. */
|
|
|
|
/* 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
|
|
*/
|
|
|
|
#include <sysdep.h>
|
|
|
|
.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. */
|
|
|
|
#ifdef SHARED
|
|
/* Load PIC register. */
|
|
LOAD_GOT (%a5)
|
|
|
|
/* Push the address of our own entry points to `.fini' and
|
|
`.init'. */
|
|
move.l __libc_csu_fini@GOT(%a5), -(%sp)
|
|
move.l __libc_csu_init@GOT(%a5), -(%sp)
|
|
|
|
pea (%a0) /* Push second argument: argv. */
|
|
move.l %d0, -(%sp) /* Push first argument: argc. */
|
|
|
|
move.l main@GOT(%a5), -(%sp)
|
|
|
|
/* Call the user's main function, and exit with its value. But
|
|
let the libc call main. */
|
|
jbsr __libc_start_main@PLTPC
|
|
#else
|
|
/* Push the address of our own entry points to `.fini' and
|
|
`.init'. */
|
|
pea __libc_csu_fini
|
|
pea __libc_csu_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
|
|
#endif
|
|
|
|
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
|