So, according to Intel, the probable cause for 0x406e3 and 0x506e3 processors to fail loading the microcode update *early* is an incompatibility when you update from a very old microcode release in BIOS/UEFI (BIOS has a revision older/smaller than 0x80) to the newer microcode updates.
This information was provided by Intel in the upstream bug report: https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/issues/31#issuecomment-761228960 However, it looks like it could have been fixed by the latest microcode update batch, from 20210608, which contains microcode revision 0xea for the 0x406e3 and 0x506e3 processors. It would be extremely helpful if anyone that had this issue could test the 20210608 microcode update and report, please. It helps if you include the contents of /proc/cpuinfo *without* the microcode update, and then the contents of /proc/cpuinfo *with* the microcode update installed. Thank you! -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1882890 Title: intel-ucode/06-4e-03 from release 20200609 hangs system in early boot To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1882890/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
