git.mutantstargoat.com Git - mdlife/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_berr         | 02 bus error
  10         .long intr_addr         | 03 address error
  11         .long intr_ill          | 04 illegal instruction
  12         .long intr_div0         | 05 zero divide
  13         .long intr_chk          | 06 chk instruction
  14         .long intr_trap         | 07 trapv instruction
  15         .long intr_segv         | 08 privilege violation
  16         .long intr_trace        | 09 trace
  17         .long intr_1010emu      | 0a line 1010 emulator
  18         .long intr_1111emu      | 0b line 1111 emulator
  19         .long intr_unk          | 0c reserved
  20         .long intr_unk          | 0d reserved
  21         .long intr_unk          | 0e format error (mc68010 only)
  22         .long intr_uninit       | 0f uninitialized interrupt vector
  23         .long intr_unk          | 10 \
  24         .long intr_unk          | 11 |
  25         .long intr_unk          | 12 |
  26         .long intr_unk          | 13  > reserved
  27         .long intr_unk          | 14 |
  28         .long intr_unk          | 15 |
  29         .long intr_unk          | 16 |
  30         .long intr_unk          | 17 /
  31         .long intr_spurious     | 18 spurious interrupt
  32         .long intr_unk          | 19 level 1 interrupt
  33         .long intr_unk          | 1a level 2 interrupt
  34         .long intr_unk          | 1b level 3 interrupt
  35         .long intr_hblank       | 1c level 4 interrupt (hblank in the mega drive)
  36         .long intr_unk          | 1d level 5 interrupt
  37         .long intr_vblank       | 1e level 6 interrupt (vblank in the mega drive)
  38         .long intr_unk          | 1f level 7 interrupt
  39         .long intr_unk          | 20 trap 0
  40         .long intr_unk          | 21 trap 1
  41         .long intr_unk          | 22 trap 2
  42         .long intr_unk          | 23 trap 3
  43         .long intr_unk          | 24 trap 4
  44         .long intr_unk          | 25 trap 5
  45         .long intr_unk          | 26 trap 6
  46         .long intr_unk          | 27 trap 7
  47         .long intr_unk          | 28 trap 8
  48         .long intr_unk          | 29 trap 9
  49         .long intr_unk          | 2a trap a
  50         .long intr_unk          | 2b trap b
  51         .long intr_unk          | 2c trap c
  52         .long intr_unk          | 2d trap d
  53         .long intr_unk          | 2e trap e
  54         .long intr_unk          | 2f trap f
  55         .long intr_unk          | 30 \
  56         .long intr_unk          | 31 |
  57         .long intr_unk          | 32 |
  58         .long intr_unk          | 33 |
  59         .long intr_unk          | 34 |
  60         .long intr_unk          | 35 |
  61         .long intr_unk          | 36 |
  62         .long intr_unk          | 37 |
  63         .long intr_unk          | 38  > reserved
  64         .long intr_unk          | 39 |
  65         .long intr_unk          | 3a |
  66         .long intr_unk          | 3b |
  67         .long intr_unk          | 3c |
  68         .long intr_unk          | 3d |
  69         .long intr_unk          | 3e |
  70         .long intr_unk          | 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         .include "vdpdefs.inc"
  76
  77 .global enable_intr
  78 enable_intr:
  79         andi.w #0xf8ff, %sr
  80         rts
  81
  82 .global disable_intr
  83 disable_intr:
  84         ori.w #0x0300, %sr
  85         rts
  86
  87 | interrupt handlers
  88         .macro intr_entry num
  89         move.w #0, -(%sp)       | pad to 32bit
  90         move.l %sp, -(%sp)
  91         pea.l \num
  92         bra.w exc_common
  93         .endm
  94
  95 intr_berr:      intr_entry 2
  96 intr_addr:      intr_entry 3
  97 intr_ill:       intr_entry 4
  98 intr_div0:      intr_entry 5
  99 intr_chk:       intr_entry 6
 100 intr_trap:      intr_entry 7
 101 intr_segv:      intr_entry 8
 102 intr_trace:     intr_entry 9
 103 intr_1010emu:   intr_entry 0xa
 104 intr_1111emu:   intr_entry 0xb
 105 intr_uninit:    intr_entry 0xf
 106 intr_spurious:  intr_entry 0x18
 107 intr_unk:       intr_entry 0
 108
 109         .extern exc_dump
 110 exc_common:
 111         jsr exc_dump
 112         stop #0x2700
 113
 114 |       .extern vblank_handler
 115
 116 intr_hblank:
 117 |       move.l %d0, -(%sp)
 118 |       move.l #0xc0020000, VDP_PORT_CTL
 119 |
 120 |       move.w testcol, %d0
 121 |       move.w %d0, VDP_PORT_DATA
 122 |       rol.b #4, %d0
 123 |       move.w %d0, testcol
 124 |
 125 |       move.l (%sp)+, %d0
 126         rte
 127
 128 |testcol: .word 0
 129
 130 intr_vblank:
 131 |       jsr vblank_handler
 132         rte