git.mutantstargoat.com Git - megatris/blob - src/intr.s

   1 | vi:filetype=gas68k:
   2 | the following will go into the .vect section which will be placed at the very
   3 | begining of the binary at address 0 by the linker (see lnkscript).
   4         .section .vect,"a"
   5         .extern start
   6 | exception vectors
   7         .long _stacktop         | 00 reset - initial SSP
   8         .long start             | 01 reset - initial PC
   9         .long intr_fatal        | 02 bus error
  10         .long intr_fatal        | 03 address error
  11         .long intr_fatal        | 04 illegal instruction
  12         .long intr_fatal        | 05 zero divide
  13         .long intr_fatal        | 06 chk instruction
  14         .long intr_fatal        | 07 trapv instruction
  15         .long intr_fatal        | 08 privilege violation
  16         .long intr_fatal        | 09 trace
  17         .long intr_fatal        | 0a line 1010 emulator
  18         .long intr_fatal        | 0b line 1111 emulator
  19         .long intr_fatal        | 0c reserved
  20         .long intr_fatal        | 0d reserved
  21         .long intr_fatal        | 0e format error (mc68010 only)
  22         .long intr_fatal        | 0f uninitialized interrupt vector
  23         .long intr_fatal        | 10 \
  24         .long intr_fatal        | 11 |
  25         .long intr_fatal        | 12 |
  26         .long intr_fatal        | 13  > reserved
  27         .long intr_fatal        | 14 |
  28         .long intr_fatal        | 15 |
  29         .long intr_fatal        | 16 |
  30         .long intr_fatal        | 17 /
  31         .long intr_fatal        | 18 spurious interrupt
  32         .long intr_fatal        | 19 level 1 interrupt
  33         .long intr_fatal        | 1a level 2 interrupt
  34         .long intr_fatal        | 1b level 3 interrupt
  35         .long intr_hblank       | 1c level 4 interrupt (hblank in the mega drive)
  36         .long intr_fatal        | 1d level 5 interrupt
  37         .long intr_vblank       | 1e level 6 interrupt (vblank in the mega drive)
  38         .long intr_fatal        | 1f level 7 interrupt
  39         .long intr_fatal        | 20 trap 0
  40         .long intr_fatal        | 21 trap 1
  41         .long intr_fatal        | 22 trap 2
  42         .long intr_fatal        | 23 trap 3
  43         .long intr_fatal        | 24 trap 4
  44         .long intr_fatal        | 25 trap 5
  45         .long intr_fatal        | 26 trap 6
  46         .long intr_fatal        | 27 trap 7
  47         .long intr_fatal        | 28 trap 8
  48         .long intr_fatal        | 29 trap 9
  49         .long intr_fatal        | 2a trap a
  50         .long intr_fatal        | 2b trap b
  51         .long intr_fatal        | 2c trap c
  52         .long intr_fatal        | 2d trap d
  53         .long intr_fatal        | 2e trap e
  54         .long intr_fatal        | 2f trap f
  55         .long intr_fatal        | 30 \
  56         .long intr_fatal        | 31 |
  57         .long intr_fatal        | 32 |
  58         .long intr_fatal        | 33 |
  59         .long intr_fatal        | 34 |
  60         .long intr_fatal        | 35 |
  61         .long intr_fatal        | 36 |
  62         .long intr_fatal        | 37 |
  63         .long intr_fatal        | 38  > reserved
  64         .long intr_fatal        | 39 |
  65         .long intr_fatal        | 3a |
  66         .long intr_fatal        | 3b |
  67         .long intr_fatal        | 3c |
  68         .long intr_fatal        | 3d |
  69         .long intr_fatal        | 3e |
  70         .long intr_fatal        | 3f /
  71
  72 | from here on we continue in the regular .text section since we don't care
  73 | where this code ends up.
  74         .text
  75
  76 .global enable_intr
  77 enable_intr:
  78         andi.w #0xf8ff, %sr
  79         rts
  80
  81 .global disable_intr
  82 disable_intr:
  83         ori.w #0x0300, %sr
  84         rts
  85
  86 | interrupt handlers
  87 intr_fatal:
  88         stop #0x2700
  89
  90         .include "vdpdefs.inc"
  91 |       .extern vblank_handler
  92 |       .extern palval
  93
  94 intr_hblank:
  95 |       move.l #0xc0020000, VDP_PORT_CTL
  96 |
  97 |       move.w testcol, %d0
  98 |       move.w %d0, VDP_PORT_DATA
  99 |       rol.b #4, %d0
 100 |       move.w %d0, testcol
 101 |
 102         rte
 103
 104 intr_vblank:
 105 |       jsr vblank_handler
 106         rte