Re: ANNOUNCE: User-space System Device Enumation (uSDE)

Dave Dodge
2003-10-31T02:34:25Z

Greg KH writes:
> On Thu, Oct 30, 2003 at 07:45:08PM -0500, David Dodge wrote:
[...]
> > Mainly I'm asking because I did try putting a hotplug script into an
> > initramfs a few weeks ago (using -test7), and it didn't appear to be
> > invoked for e.g. the VESA framebuffer. So I want to make sure this is a
> > "future" capability and not something that should have worked :-)
>
> This is something that should have worked for you today, /sbin/hotplug
> does get called during early boot, before init is started up.

Okay, I'll keep working at it. Unfortunately my main test system has
since had a major hardware failure and I haven't gotten a replacement
set up yet.

In the meantime, from a quick look at the kernel code I see this:

- invocations of /sbin/hotplug normally go through call_usermodehelper.

- kernel/kmod.c: call_usermodehelper does this prior to scheduling
any work:

if (!system_running)
return -EBUSY;

- init/main.c: system_running is not set non-zero until just
prior to starting init.

So it looks like calls to hotplug are dropped while compiled-in
drivers are initializing. Or am I missing something obvious? I
needed a one-line patch to be able to boot into initramfs; do I need
another to enable call_usermodehelper earlier?