build_library/grub.cfg: Enable grub fallback behavior

With secure boot a failed shim signature check will leave us stuck in grub. Enable automatic fallback in that case.
flatcar · Sep 10, 2024 · d2f7016 · d2f7016
1 parent ef430f5
commit d2f7016
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/build_library/grub.cfg b/build_library/grub.cfg
@@ -9,6 +9,9 @@ insmod all_video
 
 # Default menuentry id and boot timeout
 set default="flatcar"
+# Retry default boot entry - this will decrement the gpt tries counter and
+# switch to previous entry when all attempts are exhausted.
+set fallback="0 0 0"
 set timeout=1
 
 # Default kernel args for root filesystem, console, and Flatcar.