[coreboot] Coreboot FILO boot from USB

[Vipin Gahlaut]

Hi Experts,

I am trying to boot Linux from USB using coreboot and FILO and not able to
find any documentation what parameter should I set on FILO prompt. I have
enabled USB support while building FILO and libpayload.

Booting from hard disk works fine as below.
Start qemu with -hda disk.img option and give following on FILO prompt
<filo>root (hd0)
<filo>kernel /boot/vmlinuz-2.6.20 root=/dev/hda console=ttyS0
<filo>boot

Now I am trying to boot from USB and start qemu with
-usbdevice disk:disk.img

I am not finding any information what parameter should I set. I tried using
root (hd0) (hd1) (sd0) FILO is not able to find my kernel image in /boot/

See errors below.

filo> root
(hd1)
filo> kernel
/boot/vmlinuz-2.6.20
Drive 1 does not
exist

Error 15: File not
found
filo> root
(sd0)
filo> kernel
/boot/vmlinuz-2.6.20                                               Unknown
device type: sda

Error 15: File not
found
filo> root
(hd0)
filo> kernel
/boot/vmlinuz-2.6.20
Drive 0 does not
exist

Error 15: File not
found
filo>

Can someone please let me know what is expected device name for the usb I
enabled in qemu?