Overlay/File/Cart handling reworked in BLL

[42bs]

I added a set of macros to BLL to allow building a .LNX file directly from assembly using the uLoader.

Also added macros to handle overlays or asset loading from cart.

 

Example in demos/overlay.

[42bs]

And here a POC for those who use MADS:

 

	;;; compile: mads -c -b:0 test.asm -o:test.lnx

	opt ?-
	opt c+
	opt h-

BlockSize	= 1024
	org $0

	.def :?ROM_PC = 0

OVERLAY_BEGIN .macro
 .def :ROM_:1	= :?ROM_PC
	org	:2
 .def :start_:1 = *
	.endm

OVERLAY_END .macro
 .def :end_:1 = *
 .def :size_:1 = :end_:1 - :start_:1
 .def :?ROM_PC += :size_:1
	.endm

OVERLAY_DIR_ENTRY .macro
	.by (>size_:1)^$ff
	.by (<size_:1)^$ff
	.by (>start_:1)
	.by (<start_:1)
 .IF :0 == 2
	.by :2
 .ELSE
	.by 0
 .ENDIF
	.by (>(ROM_:1 & (BlockSize-1)))^$ff
	.by (<(ROM_:1 & (BlockSize-1)))^$ff
	.by ROM_:1/BlockSize
	.endm

LNX_HEADER
	.by "LYNX"
	.word 1024
	.word 1024
	.word 1
:32	.by "N"
:16	.by "M"
	.by 0			;rot
	.by 0			; audin
	.by 0			;eeprom
:3	.by 0

bootsector
	ins "ml.enc"

 .def :?ROM_PC += 52

	org	$1ff
	.byte	1+(End-Start)/256
Start:
	lda	#0
print:
	sta	0
	sty	1
loop
	lda	(0)
	beq	done
	jsr	putchar
	inc	0
	bne	loop
	inc	1
	bra	loop

done:	bra	done
putchar:
	rts

fileDirectory
	OVERLAY_DIR_ENTRY overlay1
	OVERLAY_DIR_ENTRY overlay2

:2000	.by 0			; just to fill

End:
overlay_start:
	.print "ROM_PC",?ROM_PC

 .def :?ROM_PC += (End-Start)

	.print "ROM_PC",?ROM_PC
	OVERLAY_BEGIN overlay1,overlay_start
	lda	#<info1
	ldy	#>info1
	jsr	print
	rts
info1:	.byte "overlay1",0
	OVERLAY_END overlay1

	OVERLAY_BEGIN overlay2,overlay_start
	lda	#<info2
	ldy	#>info2
	jsr	print
	rts
info2:	.byte "overlay2",0
	OVERLAY_END overlay2

 

[42bs]

Align works as well:

ROM_BLOCK_ALIGN .macro
 .def :?ROM_PC += BlockSize-(?ROM_PC & (BlockSize-1))
	.endm