sysdeps/hppa/start.S

   1 /* ELF startup code for HPPA.
   2    Copyright (C) 2002-2016 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 GNU 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    Note that people who make modified versions of this file are not
  20    obligated to grant this special exception for their modified
  21    versions; it is their choice whether to do so. The GNU Lesser
  22    General Public License gives permission to release a modified
  23    version without this exception; this exception also makes it
  24    possible to release a modified version which carries forward this
  25    exception.
  26
  27    The GNU C Library is distributed in the hope that it will be useful,
  28    but WITHOUT ANY WARRANTY; without even the implied warranty of
  29    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  30    Lesser General Public License for more details.
  31
  32    You should have received a copy of the GNU Lesser General Public
  33    License along with the GNU C Library.  If not, see
  34    <http://www.gnu.org/licenses/>.  */
  35
  36         .import main, code
  37         .import $global$, data
  38         .import __libc_start_main, code
  39         .import __libc_csu_fini, code
  40         .import __libc_csu_init, code
  41
  42         /* Have the linker create plabel words so we get PLABEL32
  43            relocs and not 21/14.  The use of 21/14 relocs is only
  44            supported in the latest dynamic linker.  */
  45 #ifdef SHARED
  46         .section        .data.rel.ro,"aw",@progbits
  47 #else
  48         .section        .rodata,"a",@progbits
  49 #endif
  50         .align 4
  51 .Lpmain:
  52         .word P%main
  53 .Lp__libc_start_main:
  54         .word P%__libc_start_main
  55 .Lp__libc_csu_fini:
  56         .word P%__libc_csu_fini
  57 .Lp__libc_csu_init:
  58         .word P%__libc_csu_init
  59 #ifdef SHARED
  60 .Lp__global:
  61         .word $global$
  62 #endif
  63
  64         .text
  65         .align 4
  66         .globl _start
  67         .export _start, ENTRY
  68         .type _start,@function
  69 _start:
  70         /* At entry to the function we have:
  71
  72                 r26 - Unused
  73                 r25 - argc
  74                 r24 - argv
  75                 r23 - False _dl_fini plabel address
  76
  77            This function is called from the lower half of RTLD_START.
  78
  79            The call to __libc_start_main expects:
  80
  81                 1. r26 - Application main
  82                 2. r25 - argc
  83                 3. r24 - argv
  84                 4. r23 - __libc_csu_init
  85                 5. sp-52 - __libc_csu_fini
  86                 6. sp-56 - rtld_fini
  87                 7. sp-60 - stackend  */
  88
  89         .proc
  90         .callinfo
  91         /* Clear previous-sp.  */
  92         stw     %r0, -4(%sp)
  93         /* Setup the stack and frame.  */
  94         stw     %rp, -20(%sp)
  95         ldo     64(%sp), %sp
  96         stw     %sp, -4(%sp)
  97         stw     %r19, -32(%sp)
  98
  99         /* argc and argv should be in 25 and 24 (2nd and 3rd argument) */
 100         /* void (*rtld_fini) (void) (6th argument) */
 101         stw     %r23, -56(%sp)
 102         /* Need to setup 1, 4, 5, and 7th arguments */
 103
 104 #ifdef SHARED
 105         /* load main (1st argument) */
 106         addil   LT'.Lpmain, %r19
 107         ldw     RT'.Lpmain(%r1), %r26
 108         ldw     0(%r26),%r26
 109         /* void (*init) (void) (4th argument) */
 110         addil   LT'.Lp__libc_csu_init, %r19
 111         ldw     RT'.Lp__libc_csu_init(%r1), %r23
 112         ldw     0(%r23), %r23
 113         /* void (*fini) (void) (5th argument) */
 114         addil   LT'.Lp__libc_csu_fini, %r19
 115         ldw     RT'.Lp__libc_csu_fini(%r1), %r22
 116         ldw     0(%r22), %r22
 117 #else
 118         /* load main (1st argument) */
 119         ldil    LR'.Lpmain, %r26
 120         ldw     RR'.Lpmain(%r26), %r26
 121         /* void (*init) (void) (4th argument) */
 122         ldil    LR'.Lp__libc_csu_init, %r23
 123         ldw     RR'.Lp__libc_csu_init(%r23), %r23
 124         /* void (*fini) (void) (5th argument) */
 125         ldil    LR'.Lp__libc_csu_fini, %r22
 126         ldw     RR'.Lp__libc_csu_fini(%r22), %r22
 127 #endif
 128         /* Store 5th argument */
 129         stw     %r22, -52(%sp)
 130         /* void *stack_end (7th argument) */
 131         stw     %sp, -60(%sp)
 132
 133 #ifdef SHARED
 134         addil   LT'.Lp__global, %r19
 135         ldw     RT'.Lp__global(%r1), %dp
 136 #else
 137         /* load global */
 138         ldil    L%$global$, %dp
 139         ldo     R%$global$(%dp), %dp
 140 #endif
 141         bl      __libc_start_main,%r2
 142         nop
 143         /* die horribly if it returned (it shouldn't) */
 144         iitlbp %r0,(%sr0,%r0)
 145         nop
 146
 147         .procend
 148
 149 /* Define a symbol for the first piece of initialized data.  */
 150         .data
 151         .globl __data_start
 152 __data_start:
 153         .long 0
 154         .weak data_start
 155         data_start = __data_start