Re: Getting boottime early in booting

On Fri, Apr 03, 2026 at 07:13:02PM -0600, Warner Losh wrote:
> On Fri, Apr 3, 2026, 7:05 PM Rick Macklem <rick.macklem@gmail.com> wrote:
> 
> > Hi,
> >
> > I'm fiddling with a NFSv4 diskless root fs setup and I've run
> > into a couple of challenges.
> >
> > 1 - I need a value that will be different each time the machine boots.
> >      I would normally use getboottime(), but for the NFS root fs mount,
> >      it just returns 0.
> >      Any ideas w.r.t. something I can acquire early in booting that will
> >      change each time the system is booted?
> >
> 
> We don't have this today. And we can't have it without hardware assist...
> though you may be ok enough with a value from the rtc.
> 
> There's work to pass the vale from the monotonicly increasing counter uefi
> provides. But not on all platforms.

We already have mechanisms to ensure that early entropy is provided on
boot.  Do you care if the value used is indeed boot time, or should it
only be unique per boot?

With the entropy loading, I believe you would get what you need on any
machine with the persistent storage.

> 
> Warner
> 
> 2 - Does anyone know how to fix "could not determine audit condition"
> >      which I get whenever I try and login when it is multiuser?
> >      (I can run single user, but since I can't login once it's multiuser??)
> >
> > Thanks for any help with these, rick
> >
> >