UserAgent: Mozilla/5.0 (X11; Linux x86_64; rv:58.0) Gecko/20100101 Firefox/58.0
Platform: 10176.68.0 stable-channel-gnawty

Steps to reproduce the problem:
1. Extract the VGA bios.
2. Create a new RW_LEGACY firmware.
3. Flash it.

What is the expected behavior?
Ctrl-L should boot the OS on a USB disc.

What went wrong?
Screen goes blank and nothing happens.

Did this work before? N/A 

Chrome version: <Copy from: 'about:version'>  Channel: stable
OS Version: 64.0.3282.144
Flash Version: Shockwave Flash 28.0 r0

After getting the FW using 'chromeos-firmwareupdate --sb_extract', I extracted the VGA bios with 'cbfstool bios.bin extract -r BOOT_STUB -n pci8086,0f31.rom -f vgabios.bin'.

Then using the 'build-byt-cros.sh' here: https://github.com/MattDevo/SeaBIOS, I rebuilt the SeaBIOS image and flashed it back with 'flashrom -w -i RW_LEGACY:<seabios_image>'.

But after rebooting, Ctrl-L results in a blank screen.

Things are working fine and ArchLinux can be booted from a USB disc, with a different VGA bios that is present in the Baytrail SeaBIOS image here:
https://www.mrchromebox.tech/files/firmware/rw_legacy/seabios-byt-mrchromebox_20170602.bin

Not sure what VGA bios is used in that image, but if I manually build a SeaBIOS payload by extracting the VGA bios from seabios-byt-mrchromebox_20170602.bin, then things work perfectly too.

It's just that the onboard VGA bios on ACER-131 doesn't seem to work properly. Any idea if an updated VGA bios for the Baytrail/Acer-131 machine can be obtained ?

Some more information:

$ strings vgabios-acer-cb3-131.bin | egrep -i 'VLV|BUILD'
1015Intel(R) VLV Mobile/Desktop PCI Accelerated SVGA BIOS
Build Number: 1015 PC 14.34  04/19/2014 05:22:13
Intel(R) VLV Mobile/Desktop Graphics Chipset Accelerated VGA BIOS
Intel(R) VLV Mobile/Desktop Graphics Controller

$ strings vgabios-mrchromebox-20170602.bin | egrep -i 'VLV|BUILD'
1020Intel(R) VLV Mobile/Desktop PCI Accelerated SVGA BIOS
Build Number: 1020 PC 14.34  08/04/2014 04:21:44
Intel(R) VLV Mobile/Desktop Graphics Chipset Accelerated VGA BIOS
Intel(R) VLV Mobile/Desktop Graphics Controller