[BippyM]

Guys,

Below is my code, but for some reason it just reboots the amiga... I cannot see why.

I have written this pretty much myself, so there will be issues. You can see where I've commented stuff out to try and pinpoint the issue, but when I step through the debugger freezes on the dbf loop, although there is no reason why it should!

If I just enable the BSR jumps at the beginning (and re-insert the RTS's) it will hang too..

; 8 Col screen 1
; Open an 8 colour low-res screen, and display a picture in asm.
;
; 19/3/2013 14:30
;
; Process for opening the screen is:
;
; 1). Backup current system. View, Copper,DMA, Audio/Disk controller (ADKON), Interrupts (INTENA, INTREQ)
; 2). Load in the GFX file and setup the bitplane pointers
; 3). Setup the palette
; 4). Create my copperlist (Include the enabling of the DMA, interrupts etc)
; 5). Copy the copper address into COP1
; 7). Start the copper to display the picture
; 8). Display picture for 5 seconds (or so)
; 9). Restore the system copper(s), view and DMA, Interrupts etc
; 10). Exit the program


	incdir "mark_asm:open_screen/"

; Some equates for hardware and libary offsets

; Base custom address

CUSTOM			equ		$dff000

; Read addresses
DMACONR			equ		$002
ADKCONR			equ		$010
INTENAR			equ		$01c
INTREQR			equ		$01e

; Write addresses
DMACON			equ		$096
ADKCON			equ		$09e
INTENA			equ		$09a
INTREQ			equ		$09c
BPLCON0			equ		$100
BPLCON1			equ		$102
BPL1MOD			equ		$108
BPL2MOD			equ		$10a
DIWSTRT			equ		$08e
DIWSTOP			equ		$090
DDFSTRT			equ		$092
DDFSTOP			equ		$094
BPL1PTH			equ		$0e0
BPL1PTL			equ		$0e2
BPL2PTH			equ		$0e4
BPL2PTL			equ		$0e6
BPL3PTH			equ		$0e0
BPL3PTL			equ		$0e2
BPL4PTH			equ		$0e4
BPL4PTL			equ		$0e6
BPL5PTH			equ		$0e0
BPL5PTL			equ		$0e2
BPL6PTH			equ		$0e4
BPL6PTL			equ		$0e6
COP1LCH			equ		$080
COP1LCL			equ		$082
COP2LCH			equ		$084
COP2LCL			equ		$086
COPJMP1			equ		$088
COPJMP2			equ		$08A


; Library offsets

execbase		equ		$4
openlibrary		equ		-552
closelibrary	equ		-414
forbid			equ		-132
permit			equ		-138
supervisor		equ		-30
loadview		equ		-222
waittof 		equ		-270
ownblitter		equ		-456
disownblitter	equ		-462
waitblit		equ		-228

; My offsets
old_View_off	equ		34
old_Clist1_off	equ		38
old_Clist2_off	equ		50

begin:

	movem.l		d0-d7/a0-a6,-(sp)				; Backup the system registers
	jsr			closesys
;	jsr			mysys
;	jsr			restoresys
	
libfail:
	movem.l		(sp)+,d0-d7/a0-a6
	moveq.l		#0,d0							; No returncode to AmigaDOS
	rts

; First we backup the system and then take control

closesys:
	move.l		execbase,a6						; Address of execbase into a6
	lea			gfxlibraryname,a1				; address of the gfx lib into a1
	moveq.l		#0,d0							; version of the library
	jsr			openlibrary(a6)					; Open the library, address is returned in d0
	move.l		d0,gfxbase						; store the address of the library
	move.l		d0,a6							; Graphics library base address into a6
	beq			libfail							; Returned a 0 in d0, then lib failed to open. Let's quit
	
	; Store the current system view and copperlists so we can restore them later
	
	move.l		old_View_off(a6),sysview
	move.l		old_Clist1_off(a6),sys1cop
	move.l		old_Clist2_off(a6),sys2cop
	
	sub.l		a1,a1							; Null view for a blank screen
	jsr			loadview(a6)					; Clear the screen
	jsr			waittof(a6)						; Wait for the top of the next frame
	jsr			waittof(a6)						; Wait again
	jsr			ownblitter(a6)
	jsr			waitblit(a6)

	; Save the contents of the sys registers (DMA, ADKON, INTENA, INTREQ)
	
	lea			CUSTOM,a6						; Base address $dff000
	
	move.w		DMACONR(a6),d0					; Store the contents of the DMA
	or.w		#$8000,d0						; Set it for re-writing later
	move.w		d0,sysdma						; store for later
	move.w		ADKCONR(a6),d0					; Store the contents of the ADKCON register
	or.w		#$8000,d0						; Set it for re-writing later
	move.w		d0,sysadkcon					; store for later
	move.w		INTENAR(a6),d0					; Store the contents of the interrupt-enable
	or.w		#$8000,d0						; Set it for re-writing later
	move.w		d0,sysintena					; store for later	
	move.w		INTREQR(a6),d0					; Store the contents of the interrupt-request
	or.w		#$8000,d0						; Set it for re-writing later
	move.w		d0,sysintreq					; store for later

	; System is now backed up, let's take it
	
	move.l		execbase,a6
	jsr			forbid(a6)						; Disable the system
	
	move.l	#$7fff,DMACON(a6)					; Disable all DMA channels
	move.l	#$85C0,DMACON(a6)					; Enable Blitter, Copper, Bitplane DMA and turn DMAEN on and enable
	move.w 	#%1100000000000000, INTENA(a6)	; IRQ set ON
	move.w 	#%0011111111111111, INTENA(a6)	; IRQ set OFF
;rts

mysys:

; Work out the bitplane sizes and addresses and pass to the copperlist.
; Bitplane info: 320*256*8. 40 words per line, 256 lines. 320x356/8bits = 10240bytes
; 10240*5=50kb : 2560 longs per bitplane
;
	lea			bp1h,a0							; first bitplane address in the copper
	moveq		#3-1,d0								; Number of bitplanes
	move.l		#image,d1							; Address of the picture into d1

	setbpl:
		move.w	d1,6(a0)							; bitplane low address pointer
		swap	d1
		move.w	d1,2(a0)							; bitplane high address
		addq.w	#8,a0
		swap d1
		add.l 	#40*256,d1							; 10240 added for next plane
	dbf d0,setbpl									; branch until all bitplanes are copied

	; load the copperlist into cop1lc
	lea mycopper,a0									; Copper address into s1
	move.l a0,COP1LCL(a6)								; and into the Cop1 register
	move.w	d0,COPJMP1(a6)								; Start the copper
	
	
		
	; Need to enable the following DMA channels: Copper, DMA, Blitter and Bitplane
		
	waitmouse:	btst	#6,$bfe001
		bne	waitmouse

		moveq	#0,d0
;		rts
rts
	
; My data structures, this includes the copperlist
	CNOP	0,4											; Ensure we are on an even address!

sys1cop:			dc.l	0							; To store the address of the first system copperlist
sys2cop:			dc.l	0							; and the second system copperlist
sysview:			dc.l	0							; The address to the system view
gfxbase:			dc.l	0							; To store the return address of the graphics.library if successfully opened

sysdma:				dc.w	0
sysadkcon			dc.w	0
sysintena			dc.w	0
sysintreq			dc.w	0

	CNOP	0,4
gfxlibraryname:		dc.b	"graphics.library",0		; Name of library we need
	CNOP	0,4
; All the below needs to be in chipram as it is accessed by the custom chips!

	section chipram,data_c

	; Bitplane information here. 3 bitplanes at 320x256
	even
	
;bp1:	dcb.b	10240,0									; Bitplane 1
;bp2:	dcb.b	10240,0									; Bitplane 2
;bp3:	dcb.b	10240,0									; Bitplane 3
	
	; Copperlist below. We need to setup the following:
	; BPLCON0 - Set an 8 colour, 3 bitplane display
	; BPLCON1 - Unset set horizontal scroll delay (Set to 0)
	; BPL1MOD & BPL2MOD - Set the modulo, again to 0
	; DIWSTRT - $2c81, and DIWSTOP to $2cc1
	; DDFSTRT - $0038 (Upper left), DDFSTOP to $00d0 (Lower right)
	; BPL1PTH & BPL1PTL - BPL3PTH & BPLPTL - Address for each bitplane in memory.
	even
mycopper:			
		dc.w	BPLCON0,$3200					; %0011001000000000
		dc.w	BPLCON1,$0000
		dc.w	BPL1MOD,$0000,BPL2MOD,$0000
		dc.w	DIWSTRT,$2C81,DIWSTOP,$2CC1
		dc.w	DDFSTRT,$0038,DDFSTOP,$00D0
bp1h:	dc.w	BPL1PTH,$0000					; Bitplane 1 high bytes register, use offset
bp1l:	dc.w	BPL1PTL,$0000					; Bitplane 1 high value, Bitplane 1 low register
bp2h:	dc.w	BPL2PTH,$0000					; Bitplane 1 high bytes register, use offset
bp2l:	dc.w	BPL2PTL,$0000					; Bitplane 1 high value, Bitplane 1 low register
bp3h:	dc.w	BPL3PTH,$0000					; Bitplane 1 high bytes register, use offset
bp3l:	dc.w	BPL3PTL,$0000					; Bitplane 1 high value, Bitplane 1 low register

Palette:
		dc.w $0180,$0000,$0182,$0AAA,$0184,$0004,$0186,$0444
		dc.w $0188,$0666,$018A,$0888,$018C,$0CCC,$018E,$0EEE

		dc.w $ffff,$fffe
		dc.w $ffff,$fffe
	even 		
image:	incbin "dh3:Open_Screen1/8cols.raw"