Basic/System include files

[guy lateur]

I'm just getting my feet wet in assembler programming, and this is my 'goodbye world' example:

mainloop:
     btst #6,$bfe001   ; u wot m8?! test what where now?
     bne mainloop
     rts

Although I do understand what this does (now), this would be much more readable (especially within a couple of months) if you could just write:

btst io_bit_lmb,cia_a

Surely there's a universally agreed upon way (set of include files) that allow us to write just that, but I can't seem to find it.
Can somebody please point me in the right direction?
TIA!

[Asman]

From my point of view I prefer raw version, because I write down this very few lines so many times (as many as sys 49152 on c64 ). And that was also my very first time with amiga asm so is not possible to forget this.
Of course if you have ndk then you can use names from hardware/cia.i

btst #CIAB_GAMEPORT0,_ciaa+ciapra

[guy lateur]

Excellent pointer, thank you! I must have come across this file, though, having searched the ndk directory for files containing bfe001. I must have been put off by it only appearing in the comments, at first sight.

So how/where does _ciaa get its value? Is it here:

XREF _ciaa

What is XREF, and how does it work?

[Asman]

There are at least two ways to obtain _ciaa. First you can do it in your source code

_ciaa		equ	$bfe001 ; or just _ciaa = $bfe001

Second you can use xref and link object with amiga.lib. Short example for vasm and vlink, cross assembling on win. Let assume that you have following code in file lmb.s

       xref _ciaa ; _ciaa is defined somewhere else 
lmb:    btst #6,_ciaa
        bne.b lmb
        rts

First you must create object.

vasm  -Fvobj lmb.s -o lmb.o

Then you must link it with amiga.lib (there is definition of _ciaa)

vlink -bamigahunk -Bstatic -s -LC:/vbcc/targets/m68k-amigaos/lib -lamiga -o lmb lmb.o

-- edit

xdef and xref are used to share symbols/labels between objects. So if you use xref label/symbol then somewhere must be xdef label/symbol. For example

;file1.s
        xdef _ciaa
_ciaa = $bfe001

;file2.s
       xref _ciaa

lmb:   btst #6,_ciaa

[guy lateur]

Thank you, Asman, for taking the time to explain this, I really appreciate this.

I'm still using AsmPro on real hardware, ATM. Do you think I can do this linking to amiga lib too?

I'll be having my holidays soon, so hopefully I'll be able to check out that cross compilation route soon, as it seems a lot easier to work like that..

[Asman]

Yes you can use AsmPro v1.17 and WL command or just choose from menu WriteLink. And then use linker.

I checked also Asm-One v1.49 RC2 and WL is broken.
Barfly is ok .

[guy lateur]

Thanks, I'll check that out!