Linux 5.7-rc2 Released With Support For Accommodating Larger AMD CPU Microcode Files

One week past the end of Linux 5.7 feature development that is marked by the first release candidate, out today like clockwork is the Linux 5.7-rc2 kernel update for testing.

With being past the merge window, Linux 5.7-rc2 is principally focused on addressing early regression/bug fall-out from the new feature material added for 5.7 -- the kernel is at more than 28.4 million lines in total this cycle.

While not strictly a bug fix, on the x86 front one notable change for Linux 5.7-rc2 is the patch talked about a few days ago that supports larger AMD CPU microcode updates that is being done for "future" AMD CPUs. That change allows for triple the size of microcode files as is currently supported by the kernel but still a small fraction of the CPU microcode file size compared to Intel processors. That change ended up getting picked up as part of the x86/urgent patches this week rather than being held off until Linux 5.8. Presumably that microcode update handling focus is for Zen 3 and that trivial patch should end up being back-ported to existing stable kernel series.

Also fixed this week was Linux 5.7-rc1 failing to boot on EFI systems.

Linus Torvalds wrote in the 5.7-rc2 announcement, "rc2 looks pretty nice and calm. Of course, it usually does that - people taking a breather after the merge window, and we may not have had enough time to see all the problem reports yet. Everything continues to look fairly normal, with commit counts right in the middle of what you'd expect for rc2. And most of the changes are tiny and don't look scary at all."

See our Linux 5.7 feature overview to learn about all the new/improved functionality of this forthcoming kernel. Depending upon how the rest of the release cycle plays out, Linux 5.7 should debut as stable in early June.