Canonical has pulled the Intel Microcode update released on November 11 for all supported versions of Ubuntu Linux to troubleshoot a startup error on some Intel Tiger Lake systems.
On November 10, Intel released a new firmware for Intel Microcode on Linux systems. After debugging, Canonical quickly fixed Intel Microcode packages on all supported versions of Ubuntu (Ubuntu 20.10, Ubuntu 20.04 LTS, Ubuntu 18.04 LTS, Ubuntu 16.04 LTS, and Ubuntu 14.04 ESM), and released new versions of kernel.
Unfortunately, the Intel Microcode update caused errors in some processors in the Intel Tiger Lake family, preventing the system from starting.
Therefore, Canonical again made the previous Intel Microcode update available only for the Tiger Lake family of processors.
The company informs users that they can use the parameter dis_ucode_ldr of the kernel in the boot menu to disable the loading of firmware for Intel Microcode in case modeof system recovery.
If you are using one of the supported versions of Ubuntu on a computer with an Intel Tiger Lake processor and have already installed yesterday's Intel Microcode update, it is recommended that you update the system again to new edition Intel Microcode that already exists in the main repository.
If you installed yesterday's Intel Microcode update and are experiencing failures to boot your system, you should use the command line orders of the kernel listed above to prevent the firmware from loading and recover your system. Then update through the terminal with the following commands (it's two in one):
sudo apt update && sudo apt full-upgrade