sysdeps/arm/nacl/dl-machine.h

   1 /* Machine-dependent ELF dynamic relocation inline functions.  ARM/NaCl version.
   2    Copyright (C) 2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #ifndef dl_machine_h
  20
  21 /* This is only needed for handling TEXTRELs and NaCl will never
  22    support TEXTRELs at all.  */
  23 #define CLEAR_CACHE(start, end) __builtin_trap ()
  24
  25 #endif
  26
  27 /* The rest is just machine-specific.
  28    This #include is outside the #ifndef because the parts of
  29    dl-machine.h used only by dynamic-link.h are outside the guard.  */
  30 #include <sysdeps/arm/dl-machine.h>
  31
  32 #ifdef dl_machine_h
  33
  34 /* Initial entry point code for the dynamic linker.
  35    The C function `_dl_start' is the real entry point;
  36    its return value is the user program's entry point.  */
  37 #undef RTLD_START
  38 #define RTLD_START asm ("\
  39 .text\n\
  40 .globl _start\n\
  41 .type _start, %function\n\
  42 .p2align 4\n\
  43 _start:\n\
  44         @ r0 has the pointer to the info block (see nacl_startup.h)\n\
  45         mov r1, sp              @ Save stack base for __libc_stack_end.\n\
  46         push {r0-r3}            @ Push those, maintaining alignment to 16.\n\
  47         mov r0, sp              @ Pointer to {info, sp} is argument.\n\
  48         sfi_bl _dl_start\n\
  49         pop {r1-r4}             @ Restore stack, getting info block into r1.\n\
  50         mov lr, #0              @ Return address for noreturn call.\n\
  51         b _dl_start_user");
  52
  53 #endif