[Opendispense] It beeps!

[Bernard Blackham]

On Wed, Jun 16, 2004 at 10:22:45PM +0800, Harry wrote:
> On Wed, 16 Jun 2004 21:37:25 +0800 Bernard Blackham <bernard@blackham.com.au> wrote:
> > mtearle and I tried burning my new version of the ROM tonight, and
> > about 7 tries later, we can get it to beep!
> 
> Great progress ! Aren't you studing for exams Mr B ? ;-)

Uhhh, yep ;)

> > I'll look into it more after exams in 5 days, but if anybody feels
> > bored in the meantime, there's a starting point.
> 
> Eep. I've made the crazy plan to start a sarge distro for Computer Angels. 

I've just solved it. Firstly I discovered the very useful m68hc1x-sim! :

$ m68hc11-gdb rom2.elf
GNU gdb 6.0
[...]
(gdb) target sim
Connected to the simulator.
(gdb) load rom2.elf
Loading section .page0, size 0x8 lma 0x0
Loading section .text, size 0xd5d lma 0x8000
Loading section .rodata, size 0x85 lma 0x8d5d
Loading section .vectors, size 0x40 lma 0xffc0
Start address 0x8cf4
Transfer rate: 29008 bits in <1 sec.
(gdb) b _start
Breakpoint 1 at 0x8cf4
(gdb) run
Starting program: /home/wheel/dagobah/vendstuff/cvs/openvend/openvend/ROM2/rom2.elf
Breakpoint 1, 0x00008cf4 in _start ()
(gdb) 

and so on. Very funky! And it told me that I was setting the stack
pointer to a pointer, not an immediate value (again, silliness on my
part). Using #_stack instead of _stack, and now gdb enters main.
Hurrah!

> > The next thing I'd like to get working is writing to the display -
> > this should make debugging *much* easier.
> 
> Let me know, post exams, when you'll be looking at it again. I can come
> and do some back seat coding if you'd like :-)

I'm currently doing it when I get bored of studying - ie, it happens
quite sporadically and randomly. I'd like to do some more sanity
checking of the code before I burn another ROM. I've been burnt by a
few too many silly mistakes tonight for my liking (eg, not putting
0x for hex values when cutting & pasting code from the disassembly
(which didn't prefix hex values with 0x)).

Anyway, will keep the list updated on progress :)

Bernard.

-- 
 Bernard Blackham <bernard at blackham dot com dot au>