[coreboot] Coreboot FILO payload build fails when USB support enabled

[ron minnich]

"reduce the boot time to the minimum possible" -- what's that mean. Do
you have a number?

ARMs boot linux to usability in 800 ms. (number seen at FOSDEM in
2007). Is that fast enough?

SPI greatly increases time to boot, and the use of SPI may be more
important than the boot loader used.

Finally, in real world use, the static timing loops and serialization
of request/response actions of simple boot loaders may make them
slower than Linux. We found that linux could pull multi-megabye
kernel+initrd downloads over the network about 10x faster than
etherboot could back in 2002. Linux has internal concurrency that can
be very effective.

Which is to say, just saying 'filo is faster' is very simplistic,
especially absent hard numbers and some real measurements. Getting
boot time down is complex and can't be reduced to a buzzphrase.

ron