After upgrading from Dunfell (YP 3.1) to Hardknott (YP 3.3), our
firmware was unable to boot.  Our target hardware is x86-64 booting in
legacy BIOS mode using grub on a variety of motherboards and CPUs.  The
grub menu would never show up; instead it would reboot immediately,
leading to an endless reboot loop.

I have two different workarounds.  Create a bbappend file for grub, and
do one of the following two things:

1) Add the following line:

CFLAGS_remove = "-O2"

2) Or make a patch to revert the following commit, and add it to SRC_URI:

https://git.savannah.gnu.org/cgit/grub.git/commit/?id=4ea7bae51f97e49c84dc67ea30b466ca8633b9f6


NOTE: this commit fixes a CVE, so do not revert it without due
consideration.


Here is my upstream bug report:

https://savannah.gnu.org/bugs/index.php?60458


Is anyone else experiencing this problem?  I am wondering how it got
past Yocto QA.

Tony Battersby
Cybernetics