Exact GitHub mirror of the upstream linux-stable tree
(git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git) — every branch
(master, linux-*.y) and every tag.
Kept in sync by .github/workflows/mirror-sync.yml
(every 30 min). Armbian builds point MAINLINE_MIRROR here so kernels are
fetched from a mirror we control, instead of a third-party one whose branches lag.
The sync workflow lives on the armbian-mirror branch; all other branches
are upstream mirrors — do not commit to them.