[Toybox] Pondering mdev...

[Rob Landley]

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.

At the design level: what is mdev needed for?

Rob