@drHirudo
currently this command can help:
tail -c +85581 up050404 | head -c 524288>pegasos2.rom
see here to learn more:
http://zero.eik.bme.hu/~balaton/qemu/amiga/
https://osdn.net/projects/qmiga/wiki/SubprojectPegasos2
if you have any difficulties, you can contact me