Re: [avr-gcc-list] C code calling ASM functions

[Erik Christiansen]

On Fri, Jan 25, 2008 at 10:40:51AM -0200, Gabriel Ortiz Lour wrote:
> 
> I would like to call functions coded in ASM from C code and was wondering if
> someone could give me some pointers on that.

The vital bit is observing the ABI, so you're not in dispute with
avr-gcc over register allocation in the calling convention. This url
informed my first steps in this direction:

http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_reg_usage

(Using this is quicker than reading the assembler generated from trial
compilation of C function calls. :-)

If there's anything that blows up when you try it, we may be able to
help, if you can't figure it out. (The gas info page is great, ... as
far as it goes.)

Erik