[Coco] CCASM procedures working!

[Roger Taylor]

Well, here is one of the first sample programs I assembled along with the 
listing so you can see what code is generated automatically by the 
assembler.  The programs I have tested are working, so I'll do a little 
more testing before I release CCASM 2.93.

In the following program, I define a procedure called "fillmem" which has 3 
formal parameters: start, len, byte
When I "call" the procedure, I pass in 3 values which are transposed to 
their formals so that the procedure can access them.
The parameters are accessed as offsets into the S stack.  Currently, there 
is no support for local variables inside of procedures except for the 
formal parameters.  I have not tested embedded procedures yet, where one 
procedure calls another.


	org	3584

screen	equ	1024
scrsiz	equ	512
color	equ	128

fillmem	proc	start:word,len:word,filler:byte
	ldx	start,s
	lda	filler,s
	ldy	len,s
a@	sta	,x+
	leay	-1,y
	bne	a@
	rts
	endproc

start	call	fillmem,screen,scrsiz,color
	call	fillmem,1024,512,128
	rts

	end	start


the listing:

CCASM 2.93: assembling cross6809.asm to pro.bin

                                          org 	3584	
                                           		
               {$0400}  screen            equ 	1024	
               {$0200}  scrsiz            equ 	512	
               {$0080}  color             equ 	128	
                                           		
                        fillmem           proc 
start:word,len:word,filler:byte	
  0E00 AE   62                            ldx 	start,s	
  0E02 A6   66                            lda 	filler,s	
  0E04 10AE 64                            ldy 	len,s	
  0E07 A7   80          a@                sta 	,x+	
  0E09 31   3F                            leay 	-1,y	
  0E0B 26   FA                            bne 	a@	
  0E0D 39                                 rts 		
                                          endproc 		
                                           		
  0E0E      8680        start             call 	fillmem,screen,scrsiz,color	
  0E10      3402
  0E12      CC
  0E13      0200
  0E15      3406
  0E17      CC
  0E18      0400
  0E1A      3406
  0E1C      BD
  0E1D      0E00
  0E1F      3265
  0E21      8680                          call 	fillmem,1024,512,128	
  0E23      3402
  0E25      CC
  0E26      0200
  0E28      3406
  0E2A      CC
  0E2B      0400
  0E2D      3406
  0E2F      BD
  0E30      0E00
  0E32      3265
  0E34 39                                 rts 		
                                           		
               {$0E0E}                    end 	start	
                                           		

color                    =[     0080]		_pr_fillmem_start        =[0002_0002]
start                    =[     0E0E]		a at 0007                   =[     0E07]
_pr_fillmem_len          =[0002_0004]		screen                   =[     0400]
_pr_fillmem_filler       =[0001_0006]		scrsiz                   =[     0200]
_pr_fillmem              =[     0E00]		_pr_fillmem_3            =[0001_0006]
_pr_fillmem_2            =[0002_0004]		_pr_fillmem_1            =[0002_0002]


[22 lines] [No Errors] ['pro.bin' is 63 bytes long]


Note that the automatic code created by the CALL function is not formatted 
in the listing, so it looks kinda rough right now for those who can read 
raw ML.  Still, this is major progress.

Anybody up for writing a stdlib or graphics lib?  :)


-- 
Roger Taylor