Bug #2890

not able to boot usb installer on Toshiba Chromebook 2

Added by johnnywhishbone over 1 year ago. Updated about 1 year ago.

Target version:
Start date:
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i am not able to boot DragonFlyBSD 4.4.1 on a Toshiba Chromebook 2 (CB30-B-104, BayTrail device, Coreboot/SeaBIOS {after patching }).
First i thought it is Coreboot/SeaBIOS-related, so i started a thread in the mailinglist:

The kernel is not able to find the usb stick or an sd card. No da*-devices are present.

Image 1:
Image 2:
dmesg (Arch Linux):
lspci -v (Arch Linux):
Coreboot-log (cbmem):

Linux is running well (after some tweaking) since it is the base of ChromeOS. But none of the BSDs. Even the most recent snapshots (i tested amd64 and i386 on usb stick and sd card) from OpenBSD, NetBSD, FreeBSD and DragonFly won’t boot. They all stop at the same point and try to find the root-device.

Please let me know if i can provide more information about the machine.

Thank you very much!
Best greetings,
— Ronny Schneider


#1 Updated by johnnywhishbone over 1 year ago

  • Target version changed from 4.2.x to Unverifiable

The xHCI (EHCI) controller seems to be not recognized, when the kernel loads. Every of the other BSDs seems to have no driver for the Bay Trail xHCI controller. Googling "xhci bay trail" it spits out a lot of bug repots and commits for several linux distros who solved the problem. I also found the data sheet for the controller ( but lacking the skills to program it myself :-(

#2 Updated by vadaszi over 1 year ago

  • Category set to Kernel


uhub0: <0x8086 XHCI root HUB, class 9/0, rev 3.00/1.00, addr 1> on usbus0

shows that the xHCI controller was apparently recognized.
Since DragonFly isn't finding any storage device, it could be that the kernel just isn't waiting long enough for the USB stick to be recognized.

You can try setting the vfs.root.wakedelay tunable (as also mentioned in the loader(8) manpage) in the bootloader prompt, to wait for e.g. 10 seconds before it tries to mount the root filesystem:

set vfs.root.wakedelay=10

#3 Updated by johnnywhishbone over 1 year ago

Thank you very much for your answer.

I'm sorry i didn't see the line. I'm still in a steep learning process since it is the first time i am really facing a problem like this and want to solve it. In the meantime i started exploring the source tree and found some entries which are referring to Bay Trail and xhci. So: mea culpa :-/

Unfortunatly setting the tunable didn't solve the problem. It waits a few more seconds but didn't find any storage device.

#4 Updated by johnnywhishbone about 1 year ago

Using FreeBSD 10.1-RELEASE amd64 mini usb image it works! The usb system is initialized correctly, usb installer stick is recognized and configured -> installer boots. Although the internal keyboard is not working, so i'm using an external usb keyboard.

With FreeBSD 10.2-RELEASE onwards it isn't working anymore. Neither the usb stick nor other plugged in usb peripherals are working. The keys of the usb keyboard are not illuminating / shining.

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