ThinkPad Yoga S1 20CD - efi var splashlogo too big prevents installing latest EUEFI MS CA

[prahal]

SplashLogoPackage-e5bbf7be-2417-499b-97db-39f4896391bc is 61KB of the 72KB available, and there needs to be more than 16KB to update the efi db to have the 2023 Microsoft CA (and even more to update the dbx).

Workaround is to download UpdateBIOS tool, extract it, create a 1 pixel black and white LOGO1.BMP and put it in the extracted UpdateBIOS folder c:\drivers\FLASH\gquj35ww\<...> folder and after disabling "Secure Rollback Prevention" (in UEFI BIOS Update Option) by setting it to "disabled" in the BIOS, run WINUPTP.EXE from this folder to update the LOGO1 half of SplashLogoPackage-e5bbf7be-2417-499b-97db-39f4896391bc which reduces it from 61KB to 31KB.
(WINUPTP detect if LOGO1.{BMP,JPG,GIF} and/or LOGO2.{BMP,JPG,GIF} exists in the folder and update the SplashLogo while flashing the BIOS)

Then one can run on Linux fwupdmgr update to update the Microsoft CA, as there is around 44KB of free space to do so.