nuclear@4: | vi:filetype=gas68k:
nuclear@0: | the following will go into the .vect section which will be placed at the very
nuclear@0: | begining of the binary at address 0 by the linker (see lnkscript).
nuclear@0: 	.section .vect,"a"
nuclear@0: 	.extern start
nuclear@0: | exception vectors
nuclear@0: 	.long _stacktop		| 00 reset - initial SSP
nuclear@0: 	.long start		| 01 reset - initial PC
nuclear@0: 	.long intr_fatal	| 02 bus error
nuclear@0: 	.long intr_fatal	| 03 address error
nuclear@0: 	.long intr_fatal	| 04 illegal instruction
nuclear@0: 	.long intr_fatal	| 05 zero divide
nuclear@0: 	.long intr_fatal	| 06 chk instruction
nuclear@0: 	.long intr_fatal	| 07 trapv instruction
nuclear@0: 	.long intr_fatal	| 08 privilege violation
nuclear@0: 	.long intr_fatal	| 09 trace
nuclear@0: 	.long intr_fatal	| 0a line 1010 emulator
nuclear@0: 	.long intr_fatal	| 0b line 1111 emulator
nuclear@0: 	.long intr_fatal	| 0c reserved
nuclear@0: 	.long intr_fatal	| 0d reserved
nuclear@0: 	.long intr_fatal	| 0e format error (mc68010 only)
nuclear@0: 	.long intr_fatal	| 0f uninitialized interrupt vector
nuclear@0: 	.long intr_fatal	| 10 \
nuclear@0: 	.long intr_fatal	| 11 |
nuclear@0: 	.long intr_fatal	| 12 |
nuclear@0: 	.long intr_fatal	| 13  > reserved
nuclear@0: 	.long intr_fatal	| 14 |
nuclear@0: 	.long intr_fatal	| 15 |
nuclear@0: 	.long intr_fatal	| 16 |
nuclear@0: 	.long intr_fatal	| 17 /
nuclear@0: 	.long intr_fatal	| 18 spurious interrupt 
nuclear@0: 	.long intr_fatal	| 19 level 1 interrupt
nuclear@0: 	.long intr_fatal	| 1a level 2 interrupt
nuclear@0: 	.long intr_fatal	| 1b level 3 interrupt
nuclear@0: 	.long intr_hblank	| 1c level 4 interrupt (hblank in the mega drive)
nuclear@0: 	.long intr_fatal	| 1d level 5 interrupt
nuclear@0: 	.long intr_vblank	| 1e level 6 interrupt (vblank in the mega drive)
nuclear@0: 	.long intr_fatal	| 1f level 7 interrupt
nuclear@0: 	.long intr_fatal	| 20 trap 0
nuclear@0: 	.long intr_fatal	| 21 trap 1
nuclear@0: 	.long intr_fatal	| 22 trap 2
nuclear@0: 	.long intr_fatal	| 23 trap 3
nuclear@0: 	.long intr_fatal	| 24 trap 4
nuclear@0: 	.long intr_fatal	| 25 trap 5
nuclear@0: 	.long intr_fatal	| 26 trap 6
nuclear@0: 	.long intr_fatal	| 27 trap 7
nuclear@0: 	.long intr_fatal	| 28 trap 8
nuclear@0: 	.long intr_fatal	| 29 trap 9
nuclear@0: 	.long intr_fatal	| 2a trap a
nuclear@0: 	.long intr_fatal	| 2b trap b
nuclear@0: 	.long intr_fatal	| 2c trap c
nuclear@0: 	.long intr_fatal	| 2d trap d
nuclear@0: 	.long intr_fatal	| 2e trap e
nuclear@0: 	.long intr_fatal	| 2f trap f
nuclear@0: 	.long intr_fatal	| 30 \
nuclear@0: 	.long intr_fatal	| 31 |
nuclear@0: 	.long intr_fatal	| 32 |
nuclear@0: 	.long intr_fatal	| 33 |
nuclear@0: 	.long intr_fatal	| 34 |
nuclear@0: 	.long intr_fatal	| 35 |
nuclear@0: 	.long intr_fatal	| 36 |
nuclear@0: 	.long intr_fatal	| 37 |
nuclear@0: 	.long intr_fatal	| 38  > reserved
nuclear@0: 	.long intr_fatal	| 39 |
nuclear@0: 	.long intr_fatal	| 3a |
nuclear@0: 	.long intr_fatal	| 3b |
nuclear@0: 	.long intr_fatal	| 3c |
nuclear@0: 	.long intr_fatal	| 3d |
nuclear@0: 	.long intr_fatal	| 3e |
nuclear@0: 	.long intr_fatal	| 3f /
nuclear@0: 
nuclear@0: | from here on we continue in the regular .text section since we don't care
nuclear@0: | where this code ends up.
nuclear@0: 	.text
nuclear@1: 
nuclear@1: .global enable_intr
nuclear@1: enable_intr:
nuclear@1: 	andi.w #0xf8ff, %sr
nuclear@1: 	rts
nuclear@1: 
nuclear@1: .global disable_intr
nuclear@1: disable_intr:
nuclear@1: 	ori.w #0x0300, %sr
nuclear@1: 	rts
nuclear@1: 
nuclear@0: | interrupt handlers
nuclear@0: intr_fatal:
nuclear@0: 	stop #0x2700
nuclear@0: 
nuclear@1: 	.include "vdpdefs.inc"
nuclear@1: 	.extern vblank_handler
nuclear@1: 	.extern palval
nuclear@1: 
nuclear@0: intr_hblank:
nuclear@4: |	move.l #0xc0020000, VDP_PORT_CTL
nuclear@4: |
nuclear@4: |	move.w testcol, %d0
nuclear@4: |	move.w %d0, VDP_PORT_DATA
nuclear@4: |	rol.b #4, %d0
nuclear@4: |	move.w %d0, testcol
nuclear@4: |
nuclear@0: 	rte
nuclear@1: 
nuclear@0: intr_vblank:
nuclear@5: 	jsr vblank_handler
nuclear@0: 	rte