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lcp / mokutil

The utility to manipulate machine owner keys
GNU General Public License v3.0
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Stuck in verbosity boot loop #71

Open sean-skt opened 10 months ago

sean-skt commented 10 months ago

Hi,

This is really hard to explain as I am new to this:

I have a Surface Book 2 and, for reasons that I won't get into, used mokutil located in the latest GParted bootable USB to turn verbosity on. Now unfortunately whenever I boot that USB drive, I get a very slow verbose output on boot. But then after awhile it just stops and reboots and now I'm stuck. I can't seem to interrupt it so that I can fully boot the GParted USB drive and turn it off again. This for occurs for all Linux distro bootable USB drives. At the moment I don't have any Linux OS installed on the SSD.

Is there anything I can do about this or am I permanently doomed? Thanks

lcp commented 10 months ago

mokutil --set-verbosity true creates a UEFI variable, SHIM_VERBOSE, to notify shim to print more. The UEFI shell provides the command, setvar, to modify UEFI variables. To delete SHIM_VERBOSE with setvar:

Shell> setvar SHIM_VERBOSE -guid 605dab50-e046-4300-abb6-3dd810dd8b23 -bs -rt -nv =

Note: You need to fetch the UEFI shell binary, put it in the EFI system partition, disable Secure Boot to boot, and then boot the shell.

The last official shell binary I find is: https://github.com/tianocore/edk2/releases/download/edk2-stable202002/ShellBinPkg.zip

On the other hand, there may be tools in Windows can manipulate UEFI variables to remove the SHIM_VERBOSE, but I'm not familiar with Windows and have no idea of such tools.