arch/m68k-all/posixc/vfork.s

   1 /*
   2  * vfork.s
   3  *
   4  *  Created on: Aug 23, 2010
   5  *      Author: misc
   6  *
   7  * $Id$
   8
   9         The jmp_buf is filled as follows (d0/d1/a0/a1 are not saved):
  10
  11         _jmp_buf        offset  contents
  12         [0]             0       old pc
  13         [1]             4       d2
  14         [2]             8       d3
  15         [3]             12      d4
  16         [4]             16      d5
  17         [5]             20      d6
  18         [6]             24      d7
  19         [7]             28      a2
  20         [8]             32      a3
  21         [9]             36      a4
  22         [10]            40      a5
  23         [11]            44      a6
  24         [12]            48      old sp
  25         [13]            52      padding
  26         [14]            56      padding
  27         [15]            60      DEBUG_MAGIC
  28 */
  29
  30 #include "aros/m68k/asm.h"
  31
  32         .text
  33         .align 2
  34         .global AROS_CDEFNAME(vfork)
  35         .type AROS_CDEFNAME(vfork),%function
  36
  37 AROS_CDEFNAME(vfork):
  38         move.l  %sp@+,%d1               /* Return address -> d1 */
  39         move.l  %sp, %a0                /* Save aside %sp */
  40         lea.l   %sp@(-4 * 16),%sp       /* Reverse space for jmp_buf */
  41         movem.l %d1-%d7/%a2-%a6,%sp@    /* Registers */
  42         move.l  %a0, %sp@(4 * 12)       /* Set %sp in jmp_buf */
  43 #if DEBUG
  44         move.l  #(DEBUG_MAGIC+1),%sp@(4 * 15)
  45 #endif
  46         move.l  %sp,%sp@-               /* Push jmp_buf (sp) address */
  47         jsr     __vfork                /* __vfork call won't return */