[code_19]

Hello! Guys I'm in so much trouble here. I really hope you can help me.

I have an Asus Chromebox. Had the dual setup, then attempted to go for the standalone. Did the factory reset, firmware backup, flashed the custom firmware but something went wrong, cause now It won't boot.

The log says:

Booting the kernel.
drm:i915_write32 Error Unknown unclaimed register before writing to a090
i8042: No controller found
gsmi: exec 0xc1ef: Unknown error 0xc1ef
usb1-4tring descriptor 0 mlformed (err=-61), defaulting to 0x0409
sdb No Caching mode page present
sdb Assuming drive cache: write through
.
.
.

I tried booting from a usb stick with Chromium, but couldn't, cause I forgot to reset the boot options, and I can't choose the usb drive. I press Escape but nothing happens, the boot menu disappears in a second, goes directly to the hard dirve.


Please tell me there is another way to boot from an external drive, so I can restore the firmware backup I got here. Or what can I do to fix this?

Thanks in advance!