FreeBSD hotplugging (Hal) info

Chuck Robey chuckr at
Mon Jun 16 18:20:38 UTC 2008

Hash: SHA1

Alexander Leidinger wrote:
> Quoting Chuck Robey <chuckr at> (from Mon, 16 Jun 2008 09:40:51
> -0400):
>> Hash: SHA1
>> Konrad Jankowski wrote:
>>>> Replying to my own mail, I realize I've worded this badly ... what I
>>>> meant is,
>>>> does any part of FreeBSD's base make any use of Hal's (the hardware
>>>> abstraction
>>>> layer) API?  If it does, and you could tell me where that is
>>>> (because I can't
>>> Base definitely doesn't use it.
>>> All you can find in base is devd.
>> Well, good news and bad.  Dropping the bad news first, I can't grep
>> for hal or
>> dbus anywhere in the devd src dir, which I think might mean it's not a
>> direct
>> user or propagator of hal.  OTOH, devd's man page lists devctl, which
>> seems
>> mightily interesting, and could extremely likely be adapted into
>> reporting to
>> hal directly.
> devctl is reporting to devd. There's no relationship to HAL.
>> My immediate worry is something I picked up from the devctl man page,
>> that it is
>> meant for a single reader.  Does that mean that I am somehow prevented
>> from
>> sharing it to both devd (or devfs) AND hal, both?  Or, do I manually
>> (well, via
>> script) create an extra devctl node?  Or, maybe, am I knocking on the
>> door of
>> the wrong mailing list?
> You can let devd issue commands in arrival/departure.

You missed the point, which is, because I am writing an Xorg Xinput driver, I
MUST use hal.  I *can* use devd or devfs, if and only if I also use the hal

I just found out about lshal, so I was able to prove that hal is aware of all
the usb devices, I just need some way to prove that hal knows this info in
real-time.  So far, using a dbus tool, I can't see where hal is broadcasting
about new usb devices, even things that show up in /var/log/messages on time.  I
need to see how hal finds out about it's devices, and either prove to myself
that it knows this in realtime, or add it.  That's why I was interested in
devctl, because it seems like the ideal method to find out about new devices,
and use that info to give it to dbus.

Maybe I could write some devfs or devd script, maybe one in python (there's a
Python interface to dbus) to tell hal about new devices, but that would be doing
it secondhand, I'd far rather get it directly from devctl.  That's why I asked
about the man p[age comment about devctl talking only to devd, I'd like to
change that.  Maybe I'll find out who wrote that, and grill that guy.

>> Please let me know, my stubborn streak has seen me too close to the
>> ending of
>> this driver of mine to consider stopping now, I just MUST answer this
>> last
>> feature worry of mine.
> Ask on gnome@ about dbus, and on x11@ about the X11 HAL stuff.
> Bye,
> Alexander.

Version: GnuPG v2.0.4 (FreeBSD)
Comment: Using GnuPG with Mozilla -


More information about the freebsd-hackers mailing list