Alexander E. Patrakov wrote:
Coldplugging is a bit more problematic. hotplug-light does load modules,
but does not recreate USB hotplug events correctly. This breaks
chmodding pseudofiles in /proc/bus/usb/xxx/yyy when USB host controller
is compiled as a non-module, and thus it will make my scanner
inaccessible for non-root when BLFS finally moves from the obsolete
"usb" group hack to the proper hotplug handlers.
I've just been working round a similar issue with an Iriver mp3 player. It uses
an altered form of fat 32. There is a kernel patch to allow it to be mounted
but the ifp aplication I used to use to access the device relied on hotplug to
change the permissions onit so non-root uses could access it. Without hotplug,
I can only put songs on the device as root. The solution was to create a udev
rule (all one line, sorry if it wraps)
ACTION="add", BUS="usb", SYSFS{manufacturer}="iRiver Limited.",
PROGRAM="/usr/sbin/ifp-nonroot.sh"
That runs a simple script /usr/sbin/ifp-nonroot.sh that looks like this
#!/bin/bash
chgrp audio $DEVICE
chmod g+rw $DEVICE
Of course the script can do almost anything so this is very powerfull, flexible and extensible.
man udev is quite informative and so is the docs/writing_udev_rules/index.html
file in the udev kernel source. That should really get installed in
/usr/share/doc. Perhaps something like
install -m 755 -d /usr/share/doc/udev_rules &&
install -m 644 docs/writing_udev_rules/index.html /usr/share/doc/udev_rules
Back to the original question: Hotplug is not needed for a minimal
system. Its use in LFS is limited to hardware detection facilities
(compare /etc/sysconfig/modules in LFS-6.1 with LFS-6.0), and BLFS
doesn't use hotplug yet. But it is useful.
To me, I don't see the need for hotplug to be in LFS, I don't think it should
be in BLFS either. If someone needs it they should write a hint. Maybe I'm
being a bit extreme, but...
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