[Buildroot] [RFC 3/6] system: add mdev-only /dev management (without devtmpfs)

Thomas Petazzoni thomas.petazzoni at free-electrons.com
Mon Sep 14 19:34:04 UTC 2015


Dear Luca Ceresoli,

On Mon, 14 Sep 2015 18:05:52 +0200, Luca Ceresoli wrote:

> But now I removed that patch, and replaced with a different
> implementation based on Arnout's suggestion of using BUSYBOX_DEVICES.

I am not sure using BUSYBOX_DEVICES is fully correct. The reason
why /dev/console is needed is *not* because of Busybox, but because of
the kernel that is opening /dev/console before handing control over
to the init application:

  http://lxr.free-electrons.com/source/init/main.c#L1011

If you do BUSYBOX_DEVICES with just /dev/console, then you will also
need a SYSVINIT_DEVICES with just /dev/console.

Though I admit my comment here is mainly nitpicking :)

> > One thing I dislike a bit is that there is quite a bit overlap between
> > S10mdev and activate-mdev. As Arnout suggested, can you just mount a
> > tmpfs in /dev in the inittab in the "mdev without devtmpfs" case, and
> > then keep the normal S10mdev script?
> 
> v2 will do things this way.

Great!

Thanks!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com


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