Hi Eric, thanks for quick reply.
> Do you really have problems or where you only preoccupied about > this case ? No really problems yet, only thinking about this. > In fact, you are wondering how the compiler should threat function calls > from an ISR. > I do not see any difference between callback or direct call. > Every procedure should preserve/restore any register, except r18-r31 and > take care of r1, r0. Yes: Pushing and popping all the registers would solve the problem. But: We have some quick ISRs, which are written in assembler. Pushing and popping all registers would be true overkill if you only need a few. Thats why I thought about a way, where callback functions store and resolve the used registers by its own. Regards, Sven _______________________________________________ AVR-GCC-list mailing list AVR-GCC-list@nongnu.org http://lists.nongnu.org/mailman/listinfo/avr-gcc-list
