arch/.unmaintained/ppc-native/exec/exception_vectors.s

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 .space 0x100
   7 .space 0x200
   8 .space 0x300
   9 .space 0x400
  10 .space 0x500
  11 .space 0x600
  12 /* handler for program type exceptions */
  13 .space 0x700
  14
  15         push    scr
  16         mflr    scr     /* save lr, so we can move it to srr0 later */
  17         push    scr
  18         mfsrr0  scr
  19         /* was it called from Supervisor function? */
  20         cmp     scr,_Supervisor_trp
  21         beq     _superv_fn
  22         /* was it called from Superstate function? */
  23         cmp     scr,_Superstate_trp
  24         beq     _supers_fn
  25
  26 -----------------------
  27 /* not yet converted to PPC */
  28
  29         /* Store trap number */
  30  pv:    move.l  #8,-(sp)
  31         bra     _TrapEntry
  32
  33         /* And handle the trap */
  34  _TrapEntry:
  35         /* Simple disable */
  36         or.w    #0x0700,sr
  37
  38         /* get some room for destination address */
  39         subq.w  #4,sp
  40
  41         /* calculate destination address without clobbering any registers */
  42         move.l  a0,-(sp)
  43         move.l  4,a0
  44         move.l  ThisTask(a0),a0
  45         move.l  tc_TrapCode(a0),4(sp)
  46         move.l  (sp)+,a0
  47
  48         /* and jump */
  49         pop     scr
  50         mtlr    scr
  51         pop     scr
  52         blr
  53
  54 ----------------------
  55
  56 _superv_fn:
  57         /* execute user function */
  58         ljmp    arg0
  59 _supers_fn:
  60         /* restore lr */
  61         pop     scr
  62         mtlr    scr
  63         /* restore scr saved in Superstate() */
  64         pop     scr
  65         /* fake "supervisor stack" address */
  66         mr      ret,sp
  67         /* return from Superstate() subroutine */
  68         blr
  69