[avr-gcc-list] Technical question about header file organization and gcrt1.S

[Larry Barello]

In gcrt1.S there are three sections for interrupt vectors.  One for the
FPSLIC chips, one for the tiny and a third, more general one for everything
else. Why?  Is it because the order of vectors changes between those three
major groups?

I am making my projects portable between IAR and GCC (!) and since IAR does
not have anything equivalent to the GCC avr-io.h nor the automatic vector
table stuff, I wrote my own.  In IAR I have an absolute segment with all
possible vectors declared, wrapped in #ifdef..., just like GCC (amazing).
Each vector has an associated address, so I can simply do this:

#ifdef TIMER0_OVF0_vect
 ORG TIMER0_OVF0_vect
 XJMP SIG_OVERFLOW0
#endif

All is well and good.  Getting back to the question: Is there any reason I
need to make separate tables for the FPSLIC and tiny parts?  Because I can
do the ORG, in IAR, it doesn't matter the ORDER of the vectors as they will
shuffle as needed.

Thanks!

P.S. GCC 3.0 (20010423) compares *very* favorably to IAR.  IAR makes better
code, but GCC runtime support is smaller. Overall, in my projects,
resulting code size is within 100 bytes out of 7kb. IAR is better only in
debug support with astudio.