Some news. I remember I have used uECC a long time ago without this kind of bug. I have rebuilt the same code (with uECC_avr defined), but I have compiled this library not with gcc 11.1.0, but with 5.4.0.
And I obtain : simavr -t -m atmega1284 -f 16000000 test2.elf Loaded 18710 .text at address 0x0 Loaded 416 .data Init... Init alea... Init random_ecc... 93A980352F127448C19FB0213622B13D5FEFC07CA4E6EA3A22234E7F0D9634FF8F2854B25A6E70F9E2063AB47040A341B54D39FD4845FB6D86CA33C8CFB5E308... 93A980352F127448C19FB0213622B13D5FEFC07CA4E6EA3A22234E7F0D9634FF8F2854B25A6E70F9E2063AB47040A341B54D39FD4845FB6D86CA33C8CFB5E308... Done... Now the question ;-) Did I find a bug or does gcc 11 need a special build option to compile uECC ? Best regards, JB