[avr-gcc-list] Embedded AVR core with 3 byte PC

[Matej K.]

I have an embedded AVR core supporting the normal (not extended) 
instruction set, with ram located at 0x8000 to 0xFFFF, 1MB flash and 
thus a 3 byte program counter.

To make some simple programs work, I've used mcu type atmega103 and 
modified the avr3.x ldscript data ORIGIN and LENGTH parameters to 
correct for the ram difference. The inits still set the stack wrong 
(0x0FFF), but since stack isn't used until I get control in main, I can 
set the stack and Y pointer to 0xFFFF there. The next problem is 
function parameter passing through stack... Since AVR GCC expects the 
return address to be 2 bytes, it calculates the offset to the passed 
parameters wrong. Can anyone see a solution to this ? Would the compiler 
need to be modified and recompiled (and subsequently libc) ?

Thanks,
Matej