On Jan 14, 2011, Richard Stallman <[email protected]> wrote:
> No, it wouldn't be impossible. A suitable userland hotplug script would
> be perfectly capable of looking for a local file that satisfies the
> request.
> It seems impossible to me. Could you explain how it could do this?
Uhh... I thought I'd already explained, but here it goes...
Nowadays, a minimal hotplug script looks like this:
# Both $DEVPATH and $FIRMWARE are already provided in the environment.
HOTPLUG_FW_DIR=/lib/firmware/
if test -f $HOTPLUG_FW_DIR/$FIRMWARE; then
echo 1 > /sys/$DEVPATH/loading # firmware found
cat $HOTPLUG_FW_DIR/$FIRMWARE > /sys/$DEVPATH/data # upload it
echo 0 > /sys/$DEVPATH/loading # upload complete
else
echo -1 > /sys/$DEVPATH/loading # firmware not found
fi
If the kernel passes userland, in addition to DEVPATH and FIRMWARE, a
HASHPREFIX, the hotplug script would run:
case $FIRMWARE in md5/*)
hash=`echo $FIRMWARE | sed 's,^md5/,,'`
for f in `cd $HOTPLUG_FW_DIR && find . ! -type d -print | sed 's,\./,,'`; do
case `echo -n $HASHPREFIX$f | md5sum` in
"$hash"[ ]*)
echo 1 > /sys/$DEVPATH/loading
cat $HOTPLUG_FW_DIR/$f > /sys/$DEVPATH/data
echo 0 > /sys/$DEVPATH/loading
exit 0
;;
esac
done
;;
esac
--
Alexandre Oliva, freedom fighter http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/ FSF Latin America board member
Free Software Evangelist Red Hat Brazil Compiler Engineer
