csu/abi-note.S

   1 /* Special .init and .fini section support.
   2    Copyright (C) 1997, 2001, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    In addition to the permissions in the GNU Lesser General Public
  11    License, the Free Software Foundation gives you unlimited
  12    permission to link the compiled version of this file with other
  13    programs, and to distribute those programs without any restriction
  14    coming from the use of this file.  (The Lesser General Public
  15    License restrictions do apply in other respects; for example, they
  16    cover modification of the file, and distribution when not linked
  17    into another program.)
  18
  19    The GNU C Library is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22    Lesser General Public License for more details.
  23
  24    You should have received a copy of the GNU Lesser General Public
  25    License along with the GNU C Library; if not, write to the Free
  26    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  27    02111-1307 USA.  */
  28
  29 /* Define an ELF note identifying the operating-system ABI that the
  30    executable was created for.  The ELF note information identifies a
  31    particular OS or coordinated development effort within which the
  32    ELF header's e_machine value plus (for dynamically linked programs)
  33    the PT_INTERP dynamic linker name and DT_NEEDED shared library
  34    names fully identify the runtime environment required by an
  35    executable.
  36
  37    The general format of ELF notes is as follows.
  38    Offsets and lengths are bytes or (parenthetical references) to the
  39    values in other fields.
  40
  41 offset  length  contents
  42 0       4       length of name
  43 4       4       length of data
  44 8       4       note type
  45 12      (0)     vendor name
  46                 - null-terminated ASCII string, padded to 4-byte alignment
  47 12+(0)  (4)     note data,
  48
  49    The GNU project and cooperating development efforts (including the
  50    Linux community) use note type 1 and a vendor name string of "GNU"
  51    for a note descriptor that indicates ABI requirements.  The note data
  52    is four 32-bit words.  The first of these is an operating system
  53    number (0=Linux, 1=Hurd, 2=Solaris, ...) and the remaining three
  54    identify the earliest release of that OS that supports this ABI.
  55    See abi-tags (top level) for details. */
  56
  57 #include <config.h>
  58 #include <abi-tag.h>            /* OS-specific ABI tag value */
  59
  60 /* The linker (GNU ld 2.8 and later) recognizes an allocated section whose
  61    name begins with `.note' and creates a PT_NOTE program header entry
  62    pointing at it. */
  63
  64         .section ".note.ABI-tag", "a"
  65         .p2align 2
  66         .long 1f - 0f           /* name length */
  67         .long 3f - 2f           /* data length */
  68         .long  1                /* note type */
  69 0:      .asciz "GNU"            /* vendor name */
  70 1:      .p2align 2
  71 2:      .long __ABI_TAG_OS      /* note data: the ABI tag */
  72         .long __ABI_TAG_VERSION
  73 3:      .p2align 2              /* pad out section */