Comment 22 for bug 1993541

Thanks for this important clarification, Andreas. I misremembered, thinking that both /sys/firmware/efi/vars/ and /sys/firmware/efi/efivars/ were mount points, and believed that this was about mounting the *deprecated* path, rather than about mounting the new path so that it's available for use in the initramfs.

As to whether this then belongs in initramfs-tools rather than mdadm, I still think mdadm is the right place even though this isn't a deprecated filesystem, because it's unusual for anything in the initramfs to need access to firmware variables - VROC is the only instance I'm aware of. So I expect this only affects mdadm, and we should keep the code close together.

Regarding risk of regression from switching to use the new interface instead of the old interface on old kernels: the interfaces of the two paths, while not identical, are similar enough that I do not expect any subtle issues with parsing of the data (it should either work all the time or none of the time). However, if you want to mitigate any possible risk on older kernels, we could adjust the initramfs script to mount efivarsfs ONLY if /sys/firmware/efi/vars is not present. Thoughts?