TBOOT boot crash observed with TPM 2.0 in UEFI mode

When TPM2.0 device is in UEFI mode, booting the kernel through TBOOT hangs. The root cause of this error is because GRUB package included with Alam Linux 8.3 does not implement the complete stack to validate kernel command line parameters.

To resolve this issue, upgrade the system to AlmaLinux 8.4/CentOS 8.4. If somehow you cannot upgrade OS, upgrade the GRUB packages to AlmaLinux 8.4 level.

After upgrading GRUB package, if you get the following error then check out this article.

can't find command 'multiboot2'

The following steps can be followed to reproduce this error.

  • At the GRUB menu edit the TBOOT kernel using the e key.
  • Scroll down to multiboot2 /tboot.gz and edit the line to enable logging as follows:

multiboot2 /tboot.gz logging=serial,memory,vga

  • Continue the boot process by entering the Ctrl-b key.
  • Note the messages between logging=serial,memory,vga and mod_start lines

TBOOT: MB2 tag found of type 1 size 44 logging=serial,memory,vga
TBOOT: MB2 tag found of type 2 size 8 GRUB 2.03
TBOOT: MB2 tag found of type 3 size 13 mod_start: 0x31ca000, mod_end: 0x4edca3a

In the above output, mod_start the line does not show the kernel parameter indicating the system has the error described in this article.

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