1/*-
2 * Copyright 2000 David E. O'Brien, John D. Polstra.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include <sys/cdefs.h>
27__FBSDID("$FreeBSD$");
28
29#include <sys/param.h>
30
31#define ABI_VENDOR	"FreeBSD"
32#define ABI_SECTION	".note.ABI-tag"
33#define ABI_NOTETYPE	1
34
35/*
36 * Special ".note" entry specifying the ABI version.  See
37 * http://www.netbsd.org/Documentation/kernel/elf-notes.html
38 * for more information.
39 *
40 * For all arches except sparc, gcc emits the section directive for the
41 * following struct with a PROGBITS type.  However, newer versions of binutils
42 * (after 2.16.90) require the section to be of NOTE type, to guarantee that the
43 * .note.ABI-tag section correctly ends up in the first page of the final
44 * executable.
45 *
46 * Unfortunately, there is no clean way to tell gcc to use another section type,
47 * so this C file (or the C file that includes it) must be compiled in multiple
48 * steps:
49 *
50 * - Compile the .c file to a .s file.
51 * - Edit the .s file to change the 'progbits' type to 'note', for the section
52 *   directive that defines the .note.ABI-tag section.
53 * - Compile the .s file to an object file.
54 *
55 * These steps are done in the invididual Makefiles for each applicable arch.
56 */
57static const struct {
58    int32_t	namesz;
59    int32_t	descsz;
60    int32_t	type;
61    char	name[sizeof ABI_VENDOR];
62    int32_t	desc;
63} abitag __attribute__ ((section (ABI_SECTION), aligned(4))) __used = {
64    sizeof ABI_VENDOR,
65    sizeof(int32_t),
66    ABI_NOTETYPE,
67    ABI_VENDOR,
68    903000
69};
70