From mboxrd@z Thu Jan 1 00:00:00 1970 From: Madper Xie Subject: Re: [BUG]: DELL XPS 8500 become a brick after fill too many entries to nvram. Date: Wed, 13 Nov 2013 20:57:49 +0800 Message-ID: <878uws1msy.fsf@redhat.com> References: <87fvr3h3b9.fsf@redhat.com> <20131111110701.GE22636@console-pimps.org> <87eh6nt8oo.fsf@redhat.com> <20131113112052.GJ22636@console-pimps.org> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-reply-to: <20131113112052.GJ22636@console-pimps.org> Sender: linux-kernel-owner@vger.kernel.org To: Matt Fleming Cc: Madper Xie , "linux-kernel@vger.kernel.org" , "linux-efi@vger.kernel.org" , Matt Fleming List-Id: linux-efi@vger.kernel.org matt@console-pimps.org writes: > On Mon, 11 Nov, at 08:38:31PM, Madper Xie wrote: >> >> matt@console-pimps.org 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. :-( > > Have you been able to calculate the safe limit of NVRAM we need to > reserve to avoid bricking your machine? > > I was interested in the DMI and other firmware strings from dmesg. -- Best, Madper Xie.