Comment 98 for bug 1082418

I tracked this down to a bunch of edge-cases in Fujitsu's UEFI implementation, the Linux kernel, and efibootmgr.

The method of restoring access by doing a CMOS-reset (shorting the CL1_CL2 test point) and flashing the BIOS [1] was already known, but I also created a tool [2] that is supposed to restore all relevant settings from within a running Linux installation. Please do make note of the list of supported configurations and of the disclaimer.

A proper kernel-side fix is pending, but it will take some time to land in mainline Linux, linux-stable and the Ubuntu kernel tree respectively.

[1] https://support.ts.fujitsu.com/
[2] https://github.com/timschumi/ah532-biostools/