Messages in this thread | | | Date | Tue, 14 Feb 2006 14:53:12 +0300 | From | Michael Tokarev <> | Subject | Re: Device enumeration (was Re: CD writing in future Linux (stirring up a hornets' nest)) |
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Olivier Galibert wrote: [] > 4- sysfs has all the information you need, just read it [] > Answer 4 would be very nice if it was correct. sysfs is pretty much > mandatory at that point, and modulo some fixable incompleteness > provides all the capability information and model names and everything > needed to find the useful devices. What it does not provide is the > mapping between a device as found in sysfs, and a device node you can > open to talk to the device. You get the major/minor, which allows you > to create a temporary device node iff you're root. Or you can scan > all the nodes in /dev to find the one to open, which is kinda > ridiculous and inefficient. Or you have to go back to udev/hal to ask > for the sysfs node/device node path mapping, and then why use sysfs in > the first place.
That's exactly the point why I always wanted to have automatic minimal-devfs- alike in kernel, similar to ndevfs but complete: so that kernel names of defices are *always* present in /dev, regardless of the presense of udev or something else. All the rest - udev, device permissions, "alternative" names (like /dev/cdrom etc) can be built on top of that "kernel naming scheme", but the key point is that we *always* have a device in /dev/ named exactly the same as kernel "thinks" of it - so eg, /proc/partitions, dmesg output, sysfs scanning etc etc will produce real and useful results.
But oh.. Am I starting new [n]devfs flamewar?
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