Re: DEVFSv50 and /dev/fb? (or /dev/fb/? ???)

David Luyer (luyer@ucs.uwa.edu.au)
Wed, 05 Aug 1998 15:07:48 +0800


> Richard you missed the whole point. Companies and clients read the FAQ
> the run away screaming. All they see are this really "ugly" naming
> scheme.
>
> --
> Terry L. Ridder
> Blue Danube Software (Blaue Donau Software)
> "We do not write software, we compose it."

Companies and clients use Solaris. I think that's all that needs to be said
on that point.

I haven't used devfs. However the two things I hope it would provide are...
* dynamically-allocated PTYs beyond 256
* fixed device names for SCSI devices independent of other SCSI devices
in the system

These two things would be really good, and if it does it in a less ugly way
than Solaris devices (it's almost impossible not to...) I'd be happy. I'd
also hope that it has the benefits I've listed below.

I haven't looked at devfs. I don't know how good or bad it is. Personally,
I think the solution should be a /proc/dev directory and people should be
able to symlink /dev to /proc/dev if they so desire, or symlink only specific
devices, or ignore it totally. If /dev is symlinked to /proc/dev, the proc
filesystem needs to be able to support a /dev/log socket being created (and
remaining until next reboot), and anything else userland does to /dev.

(just in case you haven't noticed how ugly Solaris devices are...)
cos; ls -l /dev/sd0a
lrwxrwxrwx 1 root root 12 Mar 1 1996 /dev/sd0a -> dsk/c0t3d0s0
cos; ls -l /dev/dsk/c0t3d0s0
lrwxrwxrwx 1 root root 51 Mar 1 1996 /dev/dsk/c0t3d0s0 -> ../../devices/sbus@1,f8000000/esp@0,800000/sd@3,0:a
cos; ls -l /devices/sbus@1,f8000000/esp@0,800000/sd@3,0:a
brw-r----- 1 root sys 32, 24 Mar 1 1996 /devices/sbus@1,f8000000/esp@0,800000/sd@3,0:a

Now, if devfs is ugly compared to that, then yes, it doesn't really deserve
to live. However I believe there is room for a /proc/dev populated only with
real devices, with four major advantages;
* you can instantly see what is there
* faster directory searches
* makes things a lot easier for builders of distributions
* makes it a lot easier (for the user) when adding a new device/driver

David.

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