libs/setjmp.s

   1 /* Quarn OS
   2  *
   3  * setjmp and longjmp functions
   4  *
   5  * Copyright (C) 2009 Pawel Dziepak
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along
  18  * with this program; if not, write to the Free Software Foundation, Inc.,
  19  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  */
  22
  23 .global __setjmp
  24 __setjmp:
  25         /* Get structure from pointer */
  26         movl    4(%esp), %edx
  27
  28         /* Save return address */
  29         movl    (%esp), %eax
  30         movl    %eax, 12(%edx)
  31
  32         /* Save stack pointer */
  33         movl    %esp, (%edx)
  34
  35         /* Save base pointer */
  36         movl    %ebp, 4(%edx)
  37
  38         /* Save flags */
  39         pushf
  40         popl    %eax
  41         movl    %eax, 8(%edx)
  42
  43         /* Clear eax */
  44         xorl    %eax, %eax
  45
  46         ret
  47
  48 .global __longjmp
  49 __longjmp:
  50         movl    %esp, %edx
  51
  52         /* Restore stack pointer */
  53         movl    4(%edx), %esp
  54
  55         /* Restore base pointer */
  56         movl    8(%edx), %ebp
  57
  58         /* Restore flags */
  59         movl    12(%edx), %eax
  60         pushl   %eax
  61         popf
  62
  63         /* Set eax */
  64         movl    20(%edx), %eax
  65
  66         /* Return */
  67         movl    16(%edx), %edx
  68         pushl   %edx
  69
  70         ret
  71