> However, it hangs after that and doesn't boot my kernel.
This looks like for some reason SeaBIOS might have loaded only some
beginning part of your floppy image instead of it whole. Do you use
any of my unofficial patches currently or just the SeaBIOS master? You
could insert some debug prints to the floppy loading / memory
allocation functions, or simply enable the max debug level at SeaBIOS
(I think that could be configured at coreboot's menuconfig as well)
and see if that would be enough debug info to understand what's going