6.1-PRE boot locks up, using USB keyboard

Sam Leffler sam at errno.com
Wed Mar 15 18:53:40 UTC 2006

Rick C. Petty wrote:
> On Wed, Mar 15, 2006 at 12:27:08PM -0500, John Baldwin wrote:
>> On Wednesday 15 March 2006 12:11, Rick C. Petty wrote:
>>> My BIOS (Asus A8N-E rev 1010) has no option for disabling USB keyboard
>>> support, but I can either disable the USB controller or disable the USB
>>> legacy support.  I doubt either of these is desirable.  Fortunately, I
>>> discovered the problem..
>> The "legacy support" option is the one that makes a USB keyboard look like
>> a PS/2 keyboard.
> If I disable legacy support, the USB keyboard is useless until the kernel
> comes up multi-user and usbd is started, as I expected.  Other than that,
> everything behaves identically.
>>> Whenever ukbd is loaded by /boot/loader and that
>>> device already exists in the kernel, the boot locks up after:
>>> atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
>>> when using a USB keyboard.  I would think this is a bug.  It is 100%
>>> repeatable for me.  If I comment out the line in /boot/loader.conf, the
>>> system boots nicely.
>> Ok.  There are several edge cases that can blow up if you kldload a module
>> or load a module from the loader that is already present in the kernel.
> I would think the loader or the kernel should be smart enough not to
> break when loading an already-loaded module.  Is there a workaround?
> If not, all kernels must be compiled with ukbd (if they are to support
> USB keyboards in single-user mode, e.g.).  There should also be a
> warning "BEWARE: Do not set ukbd_load in your loader.conf"  :-P
> Seriously, though, the kernel should not break when loading an unloaded
> module.  I first noticed this whenever I had umass(4) in the kernel and
> it wouldn't detect my USB memory stick but then kldload'd it, saw "File
> exists", but then it would be detected.  I remember removing umass from
> my config and it behaving quite differently.  I never had time to pursue
> that problem.  

I've had several loader/kld bugs on my todo list for a while.  For 
example loading a module with undefined references from the loader will 
cause the kernel to panic.  Feel free to dig in and provide patches...


More information about the freebsd-hackers mailing list