On Tue, Jan 21, 2014 at 11:23 AM, Anders Darander <and...@chargestorm.se> wrote: > * Hans Beckérus <hans.becke...@gmail.com> [140121 11:05]: >> Things looked ok for a while, /dev was populated properly after boot >> and all necessary file systems / mount points were created. >> We were using an ext2 fs in RAM for mounting /. >> Now, we made a change to instead use a CPIO image compressed using xz >> and enabled the support in kernel to handle this. >> This is when our problems started :( Suddenly our system booted with >> just a very minimalistic /dev folder, containing basically only a few >> of the devices probed at boot time. > >> So, the questions now are: > >> - how was /dev populated before when there was no /etc/init.d/mdev? > > I haven't checked poky-tiny, or more specifically the kernel > configurations for it. But based on the description that I cited above, > I'd guess that poky-tiny has > CONFIG_DEVTMPFS=y > CONFIG_DEVTMPFS_MOUNT=y > enabled. > Indeed (from our .config):
CONFIG_DEVTMPFS=y CONFIG_DEVTMPFS_MOUNT=y > That would mean the the kernel itself were managing /dev for you when > you were using ext2. Unfortunately, CONFIG_DEVTMPFS_MOUNT do only > automount devmptfs on /dev if you're not in an initramfs (or initrd). > Sounds reasonable. But, when moving from ext2.gz to cpio.xz, we still did not add any init script for mounting /dev, yet it is still created and populated? But only with a very limited set of devices. I guess there is a difference when the kernel mounts the cpio.xz image compared to expanding the ext2.gz in RAM with respect to how /dev is handled. But I am only guessing here. > Thus, you should add a simple initscript which mounts devtmpfs on /dev. > Thereafter, you should be fine. > Well, using the one that came from busybox-mdev rendered our /dev completely useless :( As I said, if I reduce the script to perform only 'mdev -s', then it works a lot better. So mounting /dev again seems like a bad idea. > Regarding your other questions on mdev, it's been a little while since I > used mdev. Let us know if the ideas above is enough, or if you want to > dig more into mdev. > mdev as a device manager I think we have under control, the confusion is more in our current system behavior at boot. > Cheers, > Anders > > -- > Anders Darander > ChargeStorm AB / eStorm AB _______________________________________________ yocto mailing list yocto@yoctoproject.org https://lists.yoctoproject.org/listinfo/yocto