Grub boots to black screen

padorume · September 19, 2020, 2:14pm

Hi everyone,
two days ago i updated my almost fresh fedora 32 install (installed less than a week ago) and grub suddenly “broke”. It’s not really broken but has a really strange behavior that i can’t fix.

One week ago i did a full fresh install of both windows 10 and fedora 32. The are both running in uefi mode. After the installation everything was working fine, i loaded fedora entry, grub loaded, everything worked.

After a patch i did two days ago on fedora now grub does not load after bios. i end up with a full back screen after a single blink of a “_” in the upper corner of my screen. At first i thought that grub was broken… but it isn’t! If i open the bios setup and manually boot the fedora entry i get to see grub and everything works!

Almost forgot to say that i have secure boot enabled (No nvidia driver on fedora). I don’t think this is the root of the problem because i can still run fedora by manually selecting the first boot entry.

efibootmgr output:

BootCurrent: 0004
Timeout: 0 seconds
BootOrder: 0004,0000,0001,0002
Boot0000* Windows Boot Manager
Boot0001* CD/DVD Drive 
Boot0002  Hard Drive 
Boot0004* Fedora

This is really an annoying workaround to load grub, any ideas on how i should try to fix this?

I already tried to reinstall grub following this page: https://docs.fedoraproject.org/en-US…nstalling.html
I also tried to regenerate grub config but nothing changed.

vgaetera · September 19, 2020, 2:22pm

Try to reset the GRUB environment:

sudo grub2-editenv create

padorume · September 19, 2020, 2:31pm

Tried and nothing changed

vgaetera · September 19, 2020, 2:37pm

cat /etc/default/grub; grep -v -e ^# -e ^$ /etc/fstab; \
lsblk -o +FSTYPE,UUID; sudo efibootmgr -v

What is the output?

padorume · September 19, 2020, 2:38pm

GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="resume=UUID=d42cc13e-21e3-40b0-8cf9-11dfb06b1711 rhgb quiet"
GRUB_DISABLE_RECOVERY="true"
GRUB_ENABLE_BLSCFG=true
UUID=556c62be-125d-4706-9de1-2eb6722984f7 /                       ext4    defaults        1 1
UUID=3EA4-87B0          /boot/efi               vfat    umask=0077,shortname=winnt 0 2
UUID=5c9734d7-eb04-4744-b2c1-93981f55e903 /home                   ext4    defaults        1 2
UUID=d42cc13e-21e3-40b0-8cf9-11dfb06b1711 none                    swap    defaults        0 0
NAME MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT FSTYPE UUID
sda    8:0    0   1.8T  0 disk                   
└─sda1
       8:1    0   1.8T  0 part            ntfs   888AB9D88AB9C34C
sdb    8:16   0 931.5G  0 disk                   
├─sdb1
│      8:17   0   100M  0 part /boot/efi  vfat   3EA4-87B0
├─sdb2
│      8:18   0    16M  0 part                   
├─sdb3
│      8:19   0 487.7G  0 part            ntfs   D820B1EC20B1D1AC
├─sdb4
│      8:20   0   517M  0 part            ntfs   E0624CE3624CBFD0
├─sdb5
│      8:21   0   200G  0 part /          ext4   556c62be-125d-4706-9de1-2eb6722984f7
├─sdb6
│      8:22   0   1.9G  0 part [SWAP]     swap   d42cc13e-21e3-40b0-8cf9-11dfb06b1711
└─sdb7
       8:23   0   240G  0 part /home      ext4   5c9734d7-eb04-4744-b2c1-93981f55e903
sdc    8:32   0 931.5G  0 disk                   
├─sdc1
│      8:33   0 486.8G  0 part            ext4   1521a9e9-bac9-4826-a31d-f1847f46d6cc
└─sdc2
       8:34   0 444.8G  0 part            ntfs   38E24879E2483D7E
sr0   11:0    1  1024M  0 rom                    
BootCurrent: 0004
Timeout: 0 seconds
BootOrder: 0004,0000,0001,0002
Boot0000* Windows Boot Manager	HD(1,GPT,d5798339-dc26-4cd1-8c90-36ad9d8c87c4,0x800,0x32000)/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.}...M................
Boot0001* CD/DVD Drive 	BBS(CDROM,,0x0)AMGOAMNO........o.T.S.S.T.c.o.r.p. .C.D.D.V.D.W. .S.H.-.2.2.4.B.B....................A...........................>..Gd-.;.A..MQ..L.8.R.S.W.8.6.C.B.0.A.A.1.M.1. . . . . . ......AMBO
Boot0002  Hard Drive 	BBS(HD,,0x0)AMGOAMNO........o.W.D.C. .W.D.1.0.E.Z.E.X.-.0.0.R.K.K.A.0....................A...........................>..Gd-.;.A..MQ..L. . . . .W. .-.D.M.W.1.C.2.S.2.5.7.6.1.0......AMBOAMNO........o.S.T.2.0.0.0.D.M.0.0.1.-.1.C.H.1.6.4....................A...........................>..Gd-.;.A..MQ..L. . . . . . . . . . . . .3.Z.0.4.E.2.9.R......AMBOAMNO........o.S.T.1.0.0.0.D.M.0.1.0.-.2.E.P.1.0.2....................A...........................>..Gd-.;.A..MQ..L. . . . . . . . . . . . .9.Z.V.A.A.S.C.X......AMBO
Boot0004* Fedora	HD(1,GPT,d5798339-dc26-4cd1-8c90-36ad9d8c87c4,0x800,0x32000)/File(\EFI\fedora\shimx64.efi)

vgaetera · September 19, 2020, 2:51pm

Try to upgrade the BIOS/EFI firmware if possible.
In addition, reset the BIOS/EFI configuration.
And the EFI boot configuration specifically.

padorume · September 19, 2020, 3:07pm

My mobo is not exactly new and there are no patches that i can do.

I tried to reset the whole bios to default settings but the behaviour is still the same.

I can boot directly in windows is i leave it first in boot order, but grub (fedora entry) keeps going into a black screen if i don’t run it manually from bios boot menu

vgaetera · September 19, 2020, 3:09pm

Actually, there’s an updated documentation:

padorume · September 19, 2020, 4:15pm

Thank you for your help, i managed to fix just by making some changes to grub config. It was too strange to be able to boot my os just by manually selecting fedora entry.

In /etc/default/grub in updated/added this:

GRUB_TERMINAL_OUTPUT="gfxterm"
GRUB_GFXMODE=auto

Then I regenerated my config with:

sudo grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg

Now grub shows up at full screen, at the end of the day maybe i run into some kind of issue in the way grub tried to display its own menu when it was automatically run after bios.

system · October 17, 2020, 4:15pm

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