Bug#1056998: cdrom: Installation media changes after booting it

["Thomas Schmitt" <scdbackup@gmx.net>]

Hi,

Ram Reddy wrote:
> Thomas Schmitt wrote:
> > FWIW check the BIOS L[123] cache settings [...]

This was posted by Nicholas Geovanis <nickgeovanis@gmail.com>, not by me.

My suspicion is that the Lenovo Legion EFI BIOS intentionally creates
directories and empty file "/efi/Lenovo/BIOS/SelfHealing.fd".
I do not see much benefit in investigating this further.

More riddling is the directory and file found after using the USB stick
on the Lenovo Thinkpad machines. The internet says that
"/System Volume Information/WPSettings.dat" is part of Microsoft services.
So it might be that the USB stick got in contact with MS-Windows while
or before it was plugged into the Thinkpads.
If this suspicion can be excluded then i'd say that Thinkpad has some
strange BIOS habits.

What remains for Debian in this bug report is the observation that the
integrity check of the Debian installation ISO says "Your installation
media or this file may have been corrupted" when just a harmless change
has been made in the filesystem of the EFI partition.
Some special handling of /boot/grub/efi.img during the integrity check
would cause less surprise to the user.
Like:

  "Possibly some software or firmware made changes in the EFI System
   Partition. This may be considered harmless unless booting of this
   Debian ISO encounters difficulties or other files show checksum
   mismatches, too."


Have a nice day :)

Thomas