[Buildroot] mdev problem in 2011.08 ?

[Thomas Petazzoni]

Le Sun, 18 Sep 2011 18:44:59 +0200,
Pierre Ficheux <pierre.ficheux at openwide.fr> a écrit :

> I test with QEMU + rootfs.cpio, does it matter?

So you're using the rootfs.cpio as an initrd/initramfs ?

If yes, then yes, it matters. The thing is that the kernel does not
automount the devtmpfs filesystem when an initramfs is present. So, in
Buildroot, we have an "init" wrapper script in fs/initramfs/init which
mounts devtmpfs and does some other things before starting the real
init process. However, this script is only used when you generate an
initramfs bundled into a kernel image generated by Buildroot. If you
generate a .cpio filesystem, this trick is not applied.

However, Arnout Vandecappelle has recently contributed 2 patches that
fix this by refactoring the initramfs and cpio support in Buildroot.
See:

From: "Arnout Vandecappelle (Essensium/Mind)" <arnout at mind.be>
To: buildroot at busybox.net
Subject: [Buildroot] [PATCH 1/2] cpio: fix boot with dynamic /dev
Date: Tue,  6 Sep 2011 23:16:08 +0200

From: "Arnout Vandecappelle (Essensium/Mind)" <arnout at mind.be>
To: buildroot at busybox.net
Subject: [Buildroot] [PATCH 2/2] fs/initramfs: refactor with fs/cpio
Date: Tue,  6 Sep 2011 23:16:09 +0200

The PATCH 1/2 should fix your problem, but on the long term, I think
PATCH 2/2 is the way to go. If you have the time to test and Ack those
patches, it would be nice!

Regards,

Thomas
-- 
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com