configs/*/grub/grub.cfg: reuse ARCHISO_HINT and ARCHISO_UUID passed from the embedded grub.cfg

The `grub.cfg` embedded in the GRUB binaries already sets `ARCHISO_HINT`
and `ARCHISO_UUID` in most cases. To avoid performing the same searches
multiple times, use the existing variables.

1 files changed, 7 insertions, 3 deletions

diff --git a/configs/baseline/grub/grub.cfg b/configs/baseline/grub/grub.cfg
index d606b10..e855ea9 100644
--- a/configs/baseline/grub/grub.cfg
+++ b/configs/baseline/grub/grub.cfg
@@ -25,9 +25,13 @@ if serial --unit=0 --speed=115200; then
 fi
 
 # Search for the ISO volume
-regexp --set=1:ARCHISO_HINT '^\(([^)]+)\)' "${cmdpath}"
-search --no-floppy --set=root --file '/.disk/%UUID_SEARCH_FILENAME%.uuid' --hint "${ARCHISO_HINT}"
-probe --set ARCHISO_UUID --fs-uuid "${root}"
+if [ -z "${ARCHISO_UUID}" ]; then
+    if [ -z "${ARCHISO_HINT}" ]; then
+        regexp --set=1:ARCHISO_HINT '^\(([^)]+)\)' "${cmdpath}"
+    fi
+    search --no-floppy --set=root --file '/.disk/%UUID_SEARCH_FILENAME%.uuid' --hint "${ARCHISO_HINT}"
+    probe --set ARCHISO_UUID --fs-uuid "${root}"
+fi
 
 # Set default menu entry
 default=archlinux