Re: [BUG]: DELL XPS 8500 become a brick after fill too many entriesto nvram.

From: Matt Fleming
Date: Wed Nov 13 2013 - 09:08:40 EST


On Wed, 13 Nov, at 08:57:49PM, Madper Xie wrote:
>
> matt@xxxxxxxxxxxxxxxxx writes:
>
> > On Mon, 11 Nov, at 08:38:31PM, Madper Xie wrote:
> >>
> >> matt@xxxxxxxxxxxxxxxxx writes:
> >>
> >> > On Mon, 11 Nov, at 02:15:22PM, Madper Xie wrote:
> >> >> Howdy all,
> >> >> For now we ensure at least ~5kb free space. But my dell xps still
> >> >> become a brick after I add too many entries to my nvram. So maybe 5kb
> >> >> is not safe enough. and 5kb is just aginst Samsung's laptop.
> >> >> So should we enlarge EFI_MIN_RESERVE?
> >> >
> >
> > OK, that's pretty conclusive. Thanks.
> >
> Ouch, Sorry. My mistake. Seems filling too much entries to nvram is not
> the murderer...
> For testing, I using following command to fill my nvram:
> head -c20480 /dev/urandom | efibootmgr --quiet --create --append-binary-args -
>
> For occupy lots of nvram space, I run it many times. But when I try to
> find the threshold, I find the real murderer is that command. I mean my
> dell xps will bricked even if I just run the command once and have more
> than 100kb free space...
>
> So the murderer is the new added boot entry. I don't really know if it's
> still a bug. And I apologize for my mistake. :-(

OK, it looks like the firmware Boot Manager gets very confused when it
tries to parse the Boot Load Option you created with efibootmgr. This
looks like a general firmware bug and not something we need to worry
about in the kernel.

--
Matt Fleming, Intel Open Source Technology Center
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/