[PATCH] u-boot-script: Allow OVERLAY to be a u-boot env variable as well

[Jan Kiszka <jan.kiszka@siemens.com>]

From: Jan Kiszka <jan.kiszka@siemens.com>

This allows to define the list of overlays also during boot-time,
retrieving it from a u-boot env variable. All we need to do for that is
adding a loop around loading and applying entries in the generated
script. That will interpret an entry during boot-time as list and
iterate over all entries.

In order to use this feature, the wks entry for a rootfs-u-boot
partition needs to be extended by

--sourceparams "overlays=\"\$\{my_overlays\}\""

Quoting and escaping is important to propagate ${my_overlays} into the
generated script.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

Chao, please confirm if this fully addresses your case.

  meta/recipes-bsp/u-boot-script/files/update-u-boot-script | 6 ++++--
  1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-bsp/u-boot-script/files/update-u-boot-script b/meta/recipes-bsp/u-boot-script/files/update-u-boot-script
index eb2c2955..39b9fa0f 100755
--- a/meta/recipes-bsp/u-boot-script/files/update-u-boot-script
+++ b/meta/recipes-bsp/u-boot-script/files/update-u-boot-script
@@ -62,11 +62,13 @@ if [ -n "${OVERLAYS}" ]; then
  		if ! echo $OVERLAY | grep -q "^/"; then
  			OVERLAY_PATH=/usr/lib/linux-image-${KERNEL_VERSION}/
  		fi
-		echo "echo Loading ${OVERLAY_PATH}${OVERLAY}..." >> ${BOOT_CMD}
+		echo "for entry in ${OVERLAY}; do" >> ${BOOT_CMD}
+		echo "echo Loading ${OVERLAY_PATH}\${entry}..." >> ${BOOT_CMD}
  		echo "load \${devtype} \${devnum}:${ROOT_PARTITION}" \
-		     "\${overlay_addr_r} ${OVERLAY_PATH}${OVERLAY}" \
+		     "\${overlay_addr_r} ${OVERLAY_PATH}\${entry}" \
  		     >> ${BOOT_CMD}
  		echo "fdt apply \${overlay_addr_r}" >> ${BOOT_CMD}
+		echo "done" >> ${BOOT_CMD}
  	done
  fi
  
-- 
2.31.1