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Frank Peters posted on Tue, 23 Sep 2014 10:55:58 -0400 as excerpted: |
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> Also, my example of the changes in USB device nodes is not the only |
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> recent occurrence of /dev tree modifications. The kernel folks also |
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> removed the static /dev/rtc, or real-time clock device node. In place |
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> there is now /dev/rtc1, /dev/rtc2, etc., and the intention is to |
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> dynamically allocate these nodes with udev. This change broke my use |
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> space but it was easy to fix. |
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I guess you'd be the one to ask about this... |
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Have you tried the kernel's own devtmpfs? How well does it work compared |
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to a static dev, etc? |
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I run devtmpfs but with udev (and actually now full systemd) on top, so I |
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don't know how it does by itself. But best I know, the idea is that it |
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dynamically handles the default kernel devices, popping them in place as |
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the corresponding hardware is detected. For general desktop systems udev |
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is assumed to be run on top and do fancy stuff like the /dev/disk/by-* |
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symlinks and specific non-default permissions (with default being root/ |
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root 0660 IIRC), but for embedded and systems that have a pretty static |
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device config and thus don't want/need the fancy udev stuff, devtmpfs is |
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supposed to provide basic dynamic-device-node service. |
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So I'm wondering how well it works with your sort of config by itself, |
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and whether it's a reasonable basic replacement for a static device |
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tree. It seems to me that might be the expected middle-road for those |
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who don't want/need a full udev, and since it's a pure kernel and kconfig |
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solution, including an option to have the kernel automount it without |
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userspace help, that might be what they'd point you to as an answer to |
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the otherwise userspace breakage. |
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But I haven't the foggiest whether devtmpfs would handle those dynamic USB |
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device nodes without udev, or not. My /guess/ would be that if it |
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doesn't, making it do so might be the bug-fix they'd offer if someone |
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/did/ complain about userspace breakage in that regard. |
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Like I said, you'd be the one to ask, so I am. =:^) |
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-- |
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Duncan - List replies preferred. No HTML msgs. |
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"Every nonfree program has a lord, a master -- |
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and if you use the program, he is your master." Richard Stallman |
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