Messages in this thread | | | From | Kay Sievers <> | Date | Thu, 16 Apr 2009 23:07:40 +0200 | Subject | Re: Basic rundown of udev? |
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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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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