glibc/sysdeps/alpha/elf/crti.S
2012-03-09 23:56:38 +00:00

100 lines
3.4 KiB
ArmAsm

/* Special .init and .fini section support for Alpha.
Copyright (C) 2001, 2002, 2003, 2012 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/>. */
/* crti.S puts a function prologue at the beginning of the .init and
.fini sections and defines global symbols for those addresses, so
they can be called as functions. The symbols _init and _fini are
magic and cause the linker to emit DT_INIT and DT_FINI.
This differs from what would be generated for ordinary code in that
we save and restore the GP within the function. In order for linker
relaxation to work, the value in the GP register on exit from a function
must be valid for the function entry point. Normally, a function is
contained within one object file and this is not an issue, provided
that the function reloads the gp after making any function calls.
However, _init and _fini are constructed from pieces of many object
files, all of which may have different GP values. So we must reload
the GP value from crti.o in crtn.o. */
#include <libc-symbols.h>
#include <sysdep.h>
#ifndef PREINIT_FUNCTION
# define PREINIT_FUNCTION __gmon_start__
#endif
#ifndef PREINIT_FUNCTION_WEAK
# define PREINIT_FUNCTION_WEAK 1
#endif
#if PREINIT_FUNCTION_WEAK
weak_extern (PREINIT_FUNCTION)
#else
.hidden PREINIT_FUNCTION
#endif
.section .init, "ax", @progbits
.globl _init
.type _init, @function
.usepv _init, std
_init:
ldgp $29, 0($27)
subq $30, 16, $30
#if PREINIT_FUNCTION_WEAK
lda $27, PREINIT_FUNCTION
#endif
stq $26, 0($30)
stq $29, 8($30)
#if PREINIT_FUNCTION_WEAK
beq $27, 1f
jsr $26, ($27), PREINIT_FUNCTION
ldq $29, 8($30)
1:
#else
bsr $26, PREINIT_FUNCTION !samegp
#endif
.p2align 3
.section .fini, "ax", @progbits
.globl _fini
.type _fini,@function
.usepv _fini,std
_fini:
ldgp $29, 0($27)
subq $30, 16, $30
stq $26, 0($30)
stq $29, 8($30)
.p2align 3