I'm currently reading through umm... udevd.c for udev-141. Trying to
figure out how this thing works.
Anyone care to give me a brief map? It would help. I'm just trying
to figure out how udev talks to the kernel-- i.e. 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. 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?
On Thu, Apr 16, 2009 at 22:39, John Moser <[email protected]> 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 [email protected].
> 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