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Coding > multiboot protocol?

#152065 - Tails86 - Sun Mar 09, 2008 5:04 am

I have been looking for any information I can find on the multiboot protocol for GBA. I have found some info, but not enough for my needs.

I am now using my GBA to control external hardware through the serial interface to two microcontrollers. The program that I wrote to control everything is written on a flash cart. What I want to eventually be able to do is use the microcontrollers to program the software into the GBA using the multiboot thing. I would like to just flip a switch and the whole system run with no input.

I need the full protocol so that I can start from scratch using my own program. Any help would be appreciated. Thanks!

#152066 - tepples - Sun Mar 09, 2008 5:43 am

You could start with GBATEK::MultiBoot. Or have you already read that one?
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.

#152083 - Tails86 - Sun Mar 09, 2008 3:19 pm

oooo this is very helpful! Thanks!

#152136 - Tails86 - Mon Mar 10, 2008 3:43 pm

Thanks to that document I know exactly what to expect when sending/receiving data. I'm just kinda confused as to exactly how to send and receive. I programmed a pseudo 16-bit UART into my microcontroller. I just don't know where to go from there... Is it right to assume that an idle line is high, start bit is low, and stop bit is high? How about these SC and SD lines? Are they supposed to act like CTS and RTS?

I did find someone who wrote a program in assembly for their 8051 to program the GBA. I just hate muddling through assembly code to figure out how it works!

Anyway, sorry for all the questions. I'm just lost and don't really have a plan of action as to what to do next.

#152175 - Tails86 - Tue Mar 11, 2008 2:53 am

Ok... It seems my thinking was off. I found this site: http://www.circuitcellar.com/psoc2002/winners/273.pdf
-pages 4 and 5 shows exactly what I need to know about the interface.

So, now I have the what and the how

...I think I am going to write a short tutorial when I'm done with this.