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Date:      Mon, 1 Jan 2001 21:25:50 -0600 (CST)
From:      Mike Meyer <mwm@mired.org>
To:        Tim McMillen <timcm@umich.edu>
Cc:        questions@freebsd.org
Subject:   Re: USB Modem
Message-ID:  <14929.19006.453473.127783@guru.mired.org>
In-Reply-To: <01010122222403.01840@tim.elnsng1.mi.home.com>
References:  <14929.14095.463072.675293@guru.mired.org> <01010122222403.01840@tim.elnsng1.mi.home.com>

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Tim McMillen <timcm@umich.edu> types:
> On Monday January 01, 2001 21:03, you wrote:
> > Tim McMillen <timcm@umich.edu> types:
> > > 	I think unfortunately that when a device shows up as ugen that
> > > means that the driver for it is not fully implemented yet.  I noted this
> > > before and no one corrected or clarified it.
> > You are correct. Ugen is so people can write userland drivers to talk
> > to the device.
> 	Thanks for the clarification.  But what is a userland driver?
> I thought drivers had to be in the kernel or kld's.  Is a kld considered
> userland?  Or does the ugen create enough of an interface to allow
> a running process to act as a driver?

I'm not sure there's any official definition for the term, but I meant
a program that uses a simple kernel interface of some kind (like ugen)
to talk a device more specific than what that interface is for. I
believe there's a package to talk to USB palms that can use ugen, but
haven't checked on it. cdrecord (for SCSI cd writers) would be another
example. It uses the kernel's generic SCSI interface to talk to a SCSI
device. It either recognizes which CDRW driver to use, or the user
tells it, and it then does device-driver like things via that generic
SCSI interface.

	<mike
--
Mike Meyer <mwm@mired.org>			http://www.mired.org/home/mwm/
Independent WWW/Perforce/FreeBSD/Unix consultant, email for more information.


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