LFS 6 Boot CD - 2nd round

Alexander E. Patrakov patrakov at ums.usu.ru
Fri Sep 17 08:50:20 PDT 2004

Jeremy Huntwork wrote:
>>>There is a new iso available, bootcd-6.0-20040915.iso. You can find it
>>I have tested this only remotely via qemu (due to bandwidth limitations 
>>at home). Found a bug: the kernel has been apparently built without 
>>support for hotplug.
>>Sympthoms: after "modprobe rtc" there is no /dev/rtc. But when I run 
>>"udevstart", /dev/rtc appears.
> Hmm. Looking at my .config, hotplug seems to be enabled, also you'll
> notice it's run at boot.

These are two completely different things. The coldplug initscript will 
work even with hotplug disabled.

> Just tested on the latest version of the cd here. I plugged in my usb
> flash drive, and it was seen right away, module loaded, and device nodes
> written.  /dev/sda & /dev/sda1 were not present before.  After plugging
> in the usb drive, /dev/sda & /dev/sda1 are present.

Do you confirm the issue with rtc (or floppy, it behaves similarly)? Or 
is it just a qemu artifact?

> Will build rtc into the kernel. Are there other tests we could try to
> just confirm all is well?

You should first make the cause of the problem absolutely clear, and 
only then fix it (otherwise you just hide, not fix, the problem). I 
really see two problems.

1) You are not using the latest isapnp coldplug patch, that's why floppy 
and rtc are not detected. I have sent it to the patches list some months 
ago, the patch has been ignored as unsuitable for the book.


Note that it contains a known bug WRT devices with more than one ISAPNP 
ID - only the first ID is tried.

2) REAL PROBLEM: even when I manually do a "modprobe floppy" or 
"modprobe rtc", the event is not delivered to udev (or mishandled in 
udev) and the device node is not created. Please try changing the kernel 
and/or udev versions to see if the bug goes away. You can even use qemu 
to save time on rebooting :)

Also I have a question on the kernel quality in general. Do we really 
want to ship the "stable" book with a kernel that contains a known bug 
that prevents me from writing audio CDs, when an official patch is 


Alexander E. Patrakov

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