Adam,
i.e. add 'ioport [ 0x0cf8, 0x0cff ]' to the loader config script to allow access to the PCI ports. That should fix it. For other devices this works equally.
I've allmost won at the problem after 'learning' of 'weird' strings loader | vmlinuz-2.6.24-l4,#f: WARNING: Can't map I/O space, ROOT denies page loader : (result=00004000) loader | vmlinuz-2.6.24-l4,#f: Not allowed to perform any I/O
for some time and remember about Fiasco configuration. There is the interesting option: [ ] Enable I/O port protection
that i activated it before. And when i unset this option (as it looks like above) and rebuild Fiasco, sd_mod had determined partinions on sda drive during L4Linux boot. Now everything is going fine untill boot process gets stuck when the system perfoms some I/O on ata-channels. But i think this problem lays in plane of more simple tracings of right solutions.. at least i hope;)
Thank you for your HELP!!!