nptl/sysdeps/alpha/elf/pt-initfini.c

   1 /* Special .init and .fini section support for Alpha.  NPTL version.
   2    Copyright (C) 2003 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    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* This file is compiled into assembly code which is then munged by a sed
  21    script into two files: crti.s and crtn.s.
  22
  23    * crti.s puts a function prologue at the beginning of the .init and .fini
  24    sections and defines global symbols for those addresses, so they can be
  25    called as functions.
  26
  27    * crtn.s puts the corresponding function epilogues in the .init and .fini
  28    sections.
  29
  30    This differs from what would be generated by the generic code in that
  31    we save and restore the GP within the function.  In order for linker
  32    relaxation to work, the value in the GP register on exit from a function
  33    must be valid for the function entry point.  Normally, a function is
  34    contained within one object file and this is not an issue, provided
  35    that the function reloads the gp after making any function calls.
  36    However, _init and _fini are constructed from pieces of many object
  37    files, all of which may have different GP values.  So we must reload
  38    the GP value from crti.o in crtn.o.  */
  39
  40 __asm__ ("                                              \n\
  41 #include \"defs.h\"                                     \n\
  42                                                         \n\
  43 /*@HEADER_ENDS*/                                        \n\
  44                                                         \n\
  45 /*@_init_PROLOG_BEGINS*/                                \n\
  46         .section .init, \"ax\", @progbits               \n\
  47         .globl  _init                                   \n\
  48         .type   _init,@function                         \n\
  49         .usepv  _init,std                               \n\
  50 _init:                                                  \n\
  51         ldgp    $29, 0($27)                             \n\
  52         subq    $30, 16, $30                            \n\
  53         stq     $26, 0($30)                             \n\
  54         stq     $29, 8($30)                             \n\
  55         bsr     $26, __pthread_initialize_minimal_internal !samegp \n\
  56         .align 3                                        \n\
  57 /*@_init_PROLOG_ENDS*/                                  \n\
  58                                                         \n\
  59 /*@_init_EPILOG_BEGINS*/                                \n\
  60         .section .init, \"ax\", @progbits               \n\
  61         ldq     $26, 0($30)                             \n\
  62         ldq     $29, 8($30)                             \n\
  63         addq    $30, 16, $30                            \n\
  64         ret                                             \n\
  65 /*@_init_EPILOG_ENDS*/                                  \n\
  66                                                         \n\
  67 /*@_fini_PROLOG_BEGINS*/                                \n\
  68         .section .fini, \"ax\", @progbits               \n\
  69         .globl  _fini                                   \n\
  70         .type   _fini,@function                         \n\
  71         .usepv  _fini,std                               \n\
  72 _fini:                                                  \n\
  73         ldgp    $29, 0($27)                             \n\
  74         subq    $30, 16, $30                            \n\
  75         stq     $26, 0($30)                             \n\
  76         stq     $29, 8($30)                             \n\
  77         .align 3                                        \n\
  78 /*@_fini_PROLOG_ENDS*/                                  \n\
  79                                                         \n\
  80 /*@_fini_EPILOG_BEGINS*/                                \n\
  81         .section .fini, \"ax\", @progbits               \n\
  82         ldq     $26, 0($30)                             \n\
  83         ldq     $29, 8($30)                             \n\
  84         addq    $30, 16, $30                            \n\
  85         ret                                             \n\
  86 /*@_fini_EPILOG_ENDS*/                                  \n\
  87                                                         \n\
  88 /*@TRAILER_BEGINS*/                                     \n\
  89 ");