udev in initrd

[Jeremy Katz]

On Wed, 2004-06-02 at 12:33 +0200, Thomas Woerner wrote:
> Jeremy Katz wrote:
> > On Fri, 2004-05-28 at 18:05 +0200, Thomas Woerner wrote:
> > Hmmm, this uglifies mkinitrd a lot.  Having two completely separate
> > paths for the initrd is completely unmaintainable for the long-term.  I
> > think that I'd rather cut the busybox down to just the minimal set of
> > tools needed and then still use nash as the base shell.  And actually,
> > getting it so that we're using the main busybox instead of
> > busybox-initrd would be nice (I need to look at the anaconda specific
> > config differences so that I can try to merge those to not require a
> > weird subpackage).  This would be especially as there are a few
> > "features" in nash that aren't going to be in a standard shell (things
> > like handling of quiet mode, the simple mkdmnod present, etc)

> This is a test package. I patched mkinitrd to use busybox for udev support
> only, the non-udev version is the working fallback for the user.
> 
> nash is not needed anymore with busybox::ash and busybox::linuxrc. Why using 
> and maintaining an own tool if there is nearly the same in busybox, already?

The question is whether it makes more sense to use busybox globally when
there are things that are needed that it's not going to have (having the
setquiet thing in busybox would seem bizarre as well as a few other
things).  If we're going to go to using busybox, then it has to be done
across the board.  Two different paths is a complete non-starter.

> > 
> >>4) start udev, use udevsend as hotplug
> >>5) load modules (eg. controller, filesystem)
> >>6) umount /sys
> >>7) locate root device
> > 
> > 
> > I don't like this at all.  For one thing, doesn't it currently break
> > with root=LABEL=/?  Is there a reason not to just use /dev/root here as
> > we currently do?

> /dev/root might be nice to look at, but it is not necessary and transparent at 
> all. The real boot device is available and can be used directly. LABEL=X is 
> also supported in the busybox::mount test version.

I guess I'm just not seeing how it's not transparent.  /dev/root
corresponds to whatever you passed as root=.  That translation happens
without massive amounts of magic, especially with the sysfs parsing bits
that are there now.

Jeremy