On 03/16/11 23:36, Ed W wrote: > On 16/03/2011 12:24, Matthew Lear wrote: >> Hi, >> >> I'm working on an embedded Linux platform using 2.6.32.16. I've >> successfully patched the kernel and, following a few tweaks, cross >> compiled the aufs user space tools. >> >> I'd like to use aufs for the project. One thing that is puzzling me at >> the moment is how I could use aufs to allow /dev on my r/o root file >> system to be r/w. This is so that hw vendor supplied drivers can run >> mknod in their insmod script. > > Dunno about Debian, but most people simply mount dev in some kind of > tempfs? I would have to check, but my gentoo boot scripts do this as a > matter of course when starting udev, they first check if they can mount > devpts, if not then they mount I think tempfs? > > Note devtmpfs is probably what you want to start with? Mount this to > /dev and the kernel will create basic nodes for all devices on your > system. mdev/udev then can start much later in the process and > basically becomes simply a bunch of scripts to link/rename/adj > permissions, to your dev nodes... > > It may well be that devtmpfs is all you need and you can ditch > mdev/udev..? I'm reasonably sure it's there in 2.6.32?
I was experimenting a bit yesterday and quickly came to the conclusion that mounting /dev on tmpfs or ramfs is the way to go. It seems that this is how most distros do it (I was checking my gentoo machine too). Once mounted, I can mknod the bare minimum nodes in /dev then get udev to populate the rest. After that node creation is dynamically done by udev. I've done that all now and it's working a treat. Thanks for your suggestion, though :-) Cheers, -- Matt ------------------------------------------------------------------------------ Colocation vs. Managed Hosting A question and answer guide to determining the best fit for your organization - today and in the future. http://p.sf.net/sfu/internap-sfd2d
