From: Kay Sievers <kay.sievers@vrfy.org>
To: John Moser <john.r.moser@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Basic rundown of udev?
Date: Thu, 16 Apr 2009 23:07:40 +0200 [thread overview]
Message-ID: <ac3eb2510904161407v242ada41tcd079e5a639a638d@mail.gmail.com> (raw)
In-Reply-To: <cf4f48500904161339n627e2127k7e9b4abeb0621c28@mail.gmail.com>
On Thu, Apr 16, 2009 at 22:39, John Moser <john.r.moser@gmail.com> wrote:
> I'm currently reading through umm... udevd.c for udev-141. Trying to
> figure out how this thing works.
Udev stuff is usually handled at linux-hotplug@vger.kernel.org.
> Anyone care to give me a brief map? It would help. I'm just trying
> to figure out how udev talks to the kernel
Udev just listens to broadcasted events from the kernel.
Just run:
udevadm monitor --kernel --env
and
strace udevadm monitor --kernel
and you see what's going on.
> -- i.e. will what facilities
> would I have to implement to re-implement the kernel side of udev,
> let's say if I was to run udevd as-is on Darwin or NetBSD or
> something.
Udev uses the Linux kernel device tree exported by sysfs. It offers
simplified access to the internal device structures in the kernel. Not
sure what other platforms do here.
> How does it talk to the kernel? And if you know off the
> top of your head, which source files (and functions?) am I looking at
> here?
The kernel sends the needed events from: lib/kobject_uevent.c, but
that does not include the driver core, which is in drivers/base/*, and
the exported device tree filesystem at fs/sysfs/*.
Good luck,
Kay
prev parent reply other threads:[~2009-04-16 21:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-04-16 20:39 John Moser
2009-04-16 21:07 ` Kay Sievers [this message]
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