Re: HOWTO use udev to manage /dev

Greg KH
2004-02-19T23:56:08Z

On Thu, Feb 19, 2004 at 08:46:42PM -0300, Frédéric L. W. Meunier wrote:
> On Thu, 19 Feb 2004, Greg KH wrote:
>
> > On Thu, Feb 19, 2004 at 07:22:30PM -0300, Frédéric L. W. Meunier wrote:
> > > On Thu, 19 Feb 2004, Greg KH wrote:
> > >
> > > > - modify the rc.sysinit script to call the start_udev script as one of
> > > > the first things that it does, but after /proc and /sys are mounted.
> > > > I did this with the latest Fedora startup scripts with the patch at
> > > > the end of this file.
> > > >
> > > > - make sure the /etc/udev/udev.conf file lists the udev_root as /dev.
> > > > It should contain the following line in order to work properly.
> > > > udev_root="/dev/"
> > > >
> > > > - reboot into a 2.6 kernel and watch udev create all of the initial
> > > > device nodes in /dev
> > > >
> > > >
> > > > If anyone has any problems with this, please let me, and the
> > > > linux-hotplug-devel@lists.sourceforge.net mailing list know.
> > >
> > > Unless I'm missing something, it doesn't seem to work if you
> > > don't have /dev/null before it gets mounted.
> >
> > Did you build udev using glibc or klibc? I used klibc and it worked
> > just fine, as udev and udevd does not need /dev/null to work, unlike
> > programs built against glibc.
>
> I used your instructions, so klibc.
>
> # ldd /sbin/udev*
>
> /sbin/udev:
> not a dynamic executable
> /sbin/udevd:
> not a dynamic executable
> /sbin/udevinfo:
> not a dynamic executable
> /sbin/udevsend:
> not a dynamic executable
> /sbin/udevtest:
> not a dynamic executable
>
> It doesn't complain if I mount in /udev after I boot with
> devfs, probably because it can find /dev/null etc. But I want
> to boot with devfs=nomount and use it in /dev.

I agree, that would be the best.

So if you take out the line about starting udevd, does it work for you?

How about changing the #!/bin/bash to #!/bin/sash in the first line for
the start_udev script?

What distro is this?

Can you run strace on the start_udev script after boot to see who is
needing access to /dev/null?

Oh, and if you create the /dev/null node as the first thing in the
start_udev script does that work?

thanks,

greg k-h