Messages in this thread | | | Date | Fri, 11 Jul 1997 22:34:49 +0100 (BST) | From | Christopher Turcksin <> | Subject | Re: kernel-managed /dev, revisited |
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On Thu, 10 Jul 1997, Jeff Garzik wrote:
> Each device registers an entry in a procfs structure, which creates (to > the user) a procfs device file. Major kernel subsystems handle their > own registries. I can best describe this with an example of kernel > boot-up. "procdev" is what I call this new feature. > > /proc/dev/scsi/h0t3l0 > /proc/dev/scsi/rh0t3l0 > /proc/dev/scsi/h0t4l0 > /proc/dev/scsi/rh0t4l0
Seems like a very good idea to me, but I would propose to use the same names you're already using in the existing kernels (ref. /proc/devices).
/proc/dev/scsi0/sd0 scsi disk host adapter 0 /proc/dev/scsi0/scd0 scsi disk " /proc/dev/scsi0/st0 scsi tape " /proc/dev/scsi1/sd0 scsi disk ID 0 host adapter 1 /proc/dev/ide0/hd0 master IDE drive on primary adapter /proc/dev/ide1/hd0 master IDE drive on secondary adapter /proc/dev/ramdisk/ram0 /proc/dev/tty/tty1
You get the picture.
> The key to /proc/dev's success is its correctness. The devices listed > in /proc/dev are absolutely guaranteed to exist on the system, and their > device major/minors are 100% accurate.
That should be good news for slackware users :) (no offence intented).
> The current /dev structure continues to exist, of course.
Obviously.
> The ultimate in spiffiness would be a boot parameter to the kernel, > which would say "yes dammit, scramble my /dev" -- in other words, have > the kernel update /dev such as all its entries point to /proc/dev > locations. /dev/sda would point to /proc/dev/scsi/h0t3l0, etc.
I see no reason why this should be done in the kernel. A user-mode utility should be able to do this?
> What do you think? Adding the "procdev" feature doesn't disrupt > existing systems' /dev, so legacy systems are completely undisrupted. > Kernel patch and driver authors are not forced to upgrade anything; if > you don't want to, or can't afford to add /proc/dev support to your > driver... don't. :) A kernel-maintained /proc/dev would be very > useful.
Hmm. It seems to me that support for this in the drivers is not necessary. I thought that the drivers are already registering their minor and major device numbers with the kernel somehow. This is, afaik, all you would need to construct procdev.
I could be wrong ofcourse. After all, I'm just a simple wabbit.
If there was incomplete support for this in the drivers, I would find it a lot less useful though.
--- Christopher
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