Booting from usb hard disk

[Paul B. Mahol]

On 3/23/09, Robert Noland <rnoland at freebsd.org> wrote:
> On Mon, 2009-03-23 at 11:41 -0400, Douglas Berry wrote:
>> On Mon, 23 Mar 2009 05:36:15 CDT, Robert Noland wrote:
>> > So I have my i386 install on a usb hard disk, which I can only boot
>> > on one machine now.  The one machine that I can make work has a bios
>> > option that reads "BIOS ehci handoff".  This used to work with the
>> > old usb stack.  The machines that it doesn't work on, boot the
>> > kernel, but fail to mount root, giving me the forbidding mountroot>
>> > prompt, which is immediately followed by the message saying that da0
>> > is attached.  da0 is however not listed in the available boot
>> > devices list.  I tried playing around with the timeout in
>> > vfs_mount.c, but that didn't seem to have any impact.  It has been
>> > suggested that this may be a "geom" timeout, but I don't know
>> > anything about the boot system really.
>>
>> I have been using tunefs(8) labeled partitions on my usb hard disk
>> under CURRENT. I changed the fstab entries to match the labels
>> (eg. assume mylabel is myroot, /dev/da0s1a becomes /dev/ufs/myroot)
>> It works well on most systems.  On some systems, I see the symptom
>> you show, but I am saved by the labels showing up just after the
>> mountroot prompt.  I am then able to type
>>
>> 	ufs:/dev/ufs/myroot
>>
>> and resume the boot.  Maybe this helps you?
>
> Well, I haven't tried labeling the partitions, but ufs:/dev/da0s1a
> doesn't work from the rootmount> prompt.  Even after da0 shows up.

That is strange, I just recently have used one of usb sticks (256MB) to fix
stupid sysinstall error. In my case da0 appeared after some delay but
usual da0s1a appeared after ? and I was able to mount root
partition multiple times.
I used usb via modules, on i386 revision r190297, with "boot -s"
(I hacked fbsd installation on stick because I didnt have time for fine
details ....)

Could try just with uhci (but it will be too sloow)

-- 
Paul