Hello there, Dell XPS-15-9560 laptop (SSD drive, UEFI, secure boot off).. Windows 10 pre-installed, CentOS7 installed in a separate partition and running for months w/o issue. Don't know what happened but at reboot yesterday (not even booted in Windows, just rebooted), grub has disappeared, booted in Windows by default, which apparently has taken over the UEFI boot. By booting from a USB drive w/ CentOS7 LiveGnome, I could use its grub command prompt to inspect the UEFI of the local SSD drive, see that the centos/ sub-directory and files are still there. /boot/efi/EFI/centos/: BOOT.CSV BOOTX64.CSV fonts grub.cfg grub.cfg.1501243846.rpmsave grub.cfg.1505469290.rpmsave grubenv grubx64.efi mmx64.efi shim.efi shimx64-centos.efi shimx64.efi maybe /boot/efi/EFI/Boot/ contents has been altered? /boot/efi/EFI/Boot/: bootx64.efi fbx64.efi I had a backup of the full efi partition (`dd`) but it's outdated and I feel it's a bad idea to restore the partition from it. Still from this "external" grub prompt, I could boot into my CentOS7 using: configfile (hd0,gpt1)/EFI/centos/grub.cfg At least I know how to get back to it :-). But now, how could I give the UEFI control back to grub? Is there a grub2 or grubby command I can run to make grub the default? I've read a lot and still cannot figure out exactly what to do or don't dare running commands that could make things worse. And I have the feeling the at next Windows boot, I may need to do it again.. Regards, -- wwp -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20180201/50d1275b/attachment.sig>
Chris Murphy
2018-Feb-01 17:00 UTC
[CentOS] Re-enable grub boot in UEFI (Windows took over it)
You can to use efibootmgr for this. NVRAM boot entry is what changed, not the contents of the EFI System partition. efibootmgr -v Will list all entries and Boot Order. You need to use --bootorder to make sure the CentOS entry is first. Chris Murphy
Hello Chris, On Thu, 01 Feb 2018 17:00:03 +0000 Chris Murphy <lists at colorremedies.com> wrote:> You can to use efibootmgr for this. NVRAM boot entry is what changed, not > the contents of the EFI System partition. > > efibootmgr -v > > Will list all entries and Boot Order. You need to use --bootorder to make > sure the CentOS entry is first.Interesting.. thanks for your reply! Too bad I never run this command when things were OK (in order to compare), 'cause now, what it says doesn't mention anything that seem related to the CentOS partition or I read wrong: BootCurrent: 0007 Timeout: 0 seconds BootOrder: 0001,0002,0003,0004,0005,0006,0007 Boot0000* Windows Boot Manager HD(1,GPT,a6b87338-9b9c-4a50-8fde-2447e8fdebb6,0x800,0xfa000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}.................... Boot0001* UEFI: A400 NVMe SanDisk 512GB, Partition 1 HD(1,GPT,a6b87338-9b9c-4a50-8fde-2447e8fdebb6,0x800,0xfa000)/File(EFI\Microsoft\Boot\bootmgfw.efi)..BO Boot0002* Diskette Drive BBS(Floppy,Diskette Drive,0x0)..BO Boot0003* M.2 PCIe SSD BBS(HD,P0: A400 NVMe SanDisk 512GB,0x0)..BO Boot0004* USB Storage Device BBS(USB,KingstonDataTraveler 3.0PMAP,0x0)..BO Boot0005* CD/DVD/CD-RW Drive BBS(CDROM,CD/DVD/CD-RW Drive,0x0)..BO Boot0006* Onboard NIC BBS(Network,Onboard NIC,0x0)..BO Boot0007* UEFI: KingstonDataTraveler 3.0PMAP, Partition 1 PciRoot(0x0)/Pci(0x14,0x0)/USB(16,0)/HD(1,MBR,0x61f11812,0x800,0x737f800)..BO I don't know what 0001 and 0002 refer to exactly (there's only one SSD drive in this laptop). Regards, -- wwp -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20180201/292fbfd5/attachment-0001.sig>
Kay Diederichs
2018-Feb-05 15:27 UTC
[CentOS] Re-enable grub boot in UEFI (Windows took over it)
On 02/01/2018 12:15 PM, wwp wrote:> Hello there, > > > Dell XPS-15-9560 laptop (SSD drive, UEFI, secure boot off).. Windows 10 > pre-installed, CentOS7 installed in a separate partition and running > for months w/o issue. Don't know what happened but at reboot yesterday > (not even booted in Windows, just rebooted), grub has disappeared, > booted in Windows by default, which apparently has taken over the UEFI > boot.The DELL XPS-13-9360 in its BIOS has an option (named "auto boot recovery" or similar - sorry the machine is somewhere else) that is by default enabled. I guess you have it enabled as well. This option is triggered by two unsuccessful boot trials, and leads to the loss of the grub menu, and restoration of the (non-grub) "Windows boot manager" (or whatever it's called). After being bit by it once, I disabled it. HTH, Kay P.S. I recovered my Ubuntu grub menu by booting from the Ubuntu live USB, and then sudo su mount /dev/nvme0n1p7 /mnt cd /mnt mount /dev/nvme0n1p1 boot/efi mount --bind /proc proc mount --bind /sys sys mount --bind /dev dev chroot /mnt grub-install /dev/nvme0n1 update-grub On CentOS, the last two lines would be grub2-install /dev/nvme0n1 grub2-mkconfig -o etc/grub2.cfg> > By booting from a USB drive w/ CentOS7 LiveGnome, I could use its grub > command prompt to inspect the UEFI of the local SSD drive, see that the > centos/ sub-directory and files are still there. > > /boot/efi/EFI/centos/: > BOOT.CSV > BOOTX64.CSV > fonts > grub.cfg > grub.cfg.1501243846.rpmsave > grub.cfg.1505469290.rpmsave > grubenv > grubx64.efi > mmx64.efi > shim.efi > shimx64-centos.efi > shimx64.efi > > maybe /boot/efi/EFI/Boot/ contents has been altered? > > /boot/efi/EFI/Boot/: > bootx64.efi > fbx64.efi > > I had a backup of the full efi partition (`dd`) but it's outdated and > I feel it's a bad idea to restore the partition from it. > > Still from this "external" grub prompt, I could boot into my CentOS7 > using: > configfile (hd0,gpt1)/EFI/centos/grub.cfg > > At least I know how to get back to it :-). > > But now, how could I give the UEFI control back to grub? Is there a > grub2 or grubby command I can run to make grub the default? I've read a > lot and still cannot figure out exactly what to do or don't dare > running commands that could make things worse. > > And I have the feeling the at next Windows boot, I may need to do it > again.. > > > Regards, > > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos >
Chris Murphy
2018-Feb-05 20:10 UTC
[CentOS] Re-enable grub boot in UEFI (Windows took over it)
On Mon, Feb 5, 2018 at 8:27 AM, Kay Diederichs <kay.diederichs at uni-konstanz.de> wrote:> grub-install /dev/nvme0n1Running this on computers with UEFI firmware is not good advice, it's an obsolete command. People should use the prebaked grubx64.efi binary that comes in the grub2-efi package, and is a signed binary so it can support UEFI Secure Boot. If you run grub2-install, a new unsigned grub binary is created, replacing grubx64.efi. If you have Secure Boot enabled, you will not be able to boot, until you either reinstall the grub2-efi package (or you self-sign the grub2-install created binary and then go through the process of informing the firmware this is a valid binary by using mokutil - but I estimate maybe 1 in 50 people might do this). -- Chris Murphy
Hello Kay, On Mon, 5 Feb 2018 16:27:19 +0100 Kay Diederichs <kay.diederichs at uni-konstanz.de> wrote:> On 02/01/2018 12:15 PM, wwp wrote: > > Hello there, > > > > > > Dell XPS-15-9560 laptop (SSD drive, UEFI, secure boot off).. Windows 10 > > pre-installed, CentOS7 installed in a separate partition and running > > for months w/o issue. Don't know what happened but at reboot yesterday > > (not even booted in Windows, just rebooted), grub has disappeared, > > booted in Windows by default, which apparently has taken over the UEFI > > boot. > > > The DELL XPS-13-9360 in its BIOS has an option (named "auto boot > recovery" or similar - sorry the machine is somewhere else) that is by > default enabled. I guess you have it enabled as well. > > This option is triggered by two unsuccessful boot trials, and leads to > the loss of the grub menu, and restoration of the (non-grub) "Windows > boot manager" (or whatever it's called). > > After being bit by it once, I disabled it.At last I could reboot the system, and could verify that, you're right, there's a Bios option to restore factory settings in case of a (more or less) parametrable amount of boot failures. I disabled it as well, this is way too dangerous in case of booting from USB flashdrives (for instance) and can be enabled back if it's really needed. Thanks! Regards, -- wwp -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 836 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20180226/2423b745/attachment-0001.sig>