freebsd-dev/lib/csu/common/crtbegin.c
John Polstra f6d15b87f8 This is step 1 in an effort to unify the start-up files for the
various architectures.  Now all the work is done in crtbegin.c.
It doesn't contain any assembly language code, so it should work
fine on all architectures.  (I have tested it on the i386 and the
alpha.) The old assembly language files crt[in].S are now empty
shells that generate no code or data.  They should not be removed
any time soon, because the various versions of gcc in src and ports
expect them to exist.

Next I will move crtbegin.c into a new common machine-independent
directory, and adjust the i386-elf Makefile to use that version.
After that I will adjust the alpha Makefile to use the common
version too.

Requested by:	obrien
2000-05-19 04:32:17 +00:00

103 lines
2.9 KiB
C

/*-
* Copyright 1996, 1997, 1998, 2000 John D. Polstra.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/param.h>
#define ABI_VENDOR "FreeBSD"
#define ABI_SECTION ".note.ABI-tag"
#define ABI_NOTETYPE 1
typedef void (*fptr)(void);
static fptr ctor_list[1] __attribute__((section(".ctors"))) = { (fptr) -1 };
static fptr dtor_list[1] __attribute__((section(".dtors"))) = { (fptr) -1 };
static void
do_ctors(void)
{
fptr *fpp;
for(fpp = ctor_list + 1; *fpp != 0; ++fpp)
;
while(--fpp > ctor_list)
(**fpp)();
}
static void
do_dtors(void)
{
fptr *fpp;
for(fpp = dtor_list + 1; *fpp != 0; ++fpp)
(**fpp)();
}
/*
* With very large programs on some architectures (e.g., the Alpha),
* it is possible to get relocation overflows on the limited
* displacements of call/bsr instructions. It is particularly likely
* for the calls from _init() and _fini(), because they are in
* separate sections. Avoid the problem by forcing indirect calls.
*/
static void (*p_do_ctors)(void) = do_ctors;
static void (*p_do_dtors)(void) = do_dtors;
extern void _init(void) __attribute__((section(".init")));
void
_init(void)
{
(*p_do_ctors)();
}
extern void _fini(void) __attribute__((section(".fini")));
void
_fini(void)
{
(*p_do_dtors)();
}
/*
* Special ".note" entry specifying the ABI version. See
* http://www.netbsd.org/Documentation/kernel/elf-notes.html
* for more information.
*/
static const struct {
int32_t namesz;
int32_t descsz;
int32_t type;
char name[sizeof ABI_VENDOR];
int32_t desc;
} abitag __attribute__ ((section (ABI_SECTION))) = {
sizeof ABI_VENDOR,
sizeof(int32_t),
ABI_NOTETYPE,
ABI_VENDOR,
__FreeBSD_version
};