On Tue, Aug 20, 2013 at 03:08:37PM -0500, Rob Landley wrote: > On 08/19/2013 11:13:15 PM, Isaac wrote: > >Hello, > >I've noticed that in mdev coldplug (mdev -s) is supported, but > >hotplug is > >TODO. > >I also note that an optional (busybox) fourth field is not supported. > >This is >dir/ to link or =dir/ to move the device into /dev/dir/; > > > >mice root:root 0766 =input/ > >#creates /dev/input/mice > > > >is one example. > >Without these mdev creates a flat directory not grouped by subsystem. > > > >I'm thinking about poking at mdev and seeing if I can add these > >features. > >Any thoughts on this (higher priorities, hints as to how to proceed)? > > These days mdev should depend on devtmpfs being there, so I'm not > sure how much is left for it to do. That handles populating the > directory, making entries show up and go away, getting permissions > and even ownership right (albeit for a hardwired list of uid/gid > that Greg KH thought was a good idea). The kernel is now handling > firmware loading.
Unless you have to use an older kernel (I'm using 2.6.32 on one computer because ath5k doesn't work and madwifi-hal is the only driver that does, but it's abandoned now), want to use different permissions/gids, need to load firmware for a proprietary driver (IIRC, the kconfig entry for userspace firmware loading claims that out-of-tree drivers need a hotplug helper; of course I haven't tested), or you use a set of paths that doesn't match the kernel default. > > At the design level: what is mdev needed for? The biggest reason to have a hotplug helper now is to autoload modules. I guess that means modprobe is higher up. (Do we want to use depmod when we use modprobe? The alternative is doing a file-by-file search, which is more complicated.) And a different hotplug helper might be in order; shell-wise, someone might use something vaguely like this: #!/bin/sh [ -n "$MODALIAS" ] && { modprobe -bq "$MODALIAS" || env >>/var/log/nodriver } #Read from disk to trigger enumeration of partitions-is this still needed? if [ -n "${DEVNAME}" -a -n "${DEVTYPE}" ] case $DEVTYPE in disk) dd if=/dev/$DEVNAME of=/dev/null count=1 ;; *) ;; esac fi Thanks, Isaac Dunham _______________________________________________ Toybox mailing list Toybox@lists.landley.net http://lists.landley.net/listinfo.cgi/toybox-landley.net