gemini: add wiligear image build code

They were dropped with 6409b159e8 ("gemini: switch to 4.14") without
any explaination.

The image generation is disabled for now as it would break the build for
the target. The mkfwimage2 call need to be adjusted to reflect the real
size of kernel and rootfs. Nevertheless, add the required code to give
interested parties a chance to fix the remaining issues.

The dts would need to use the ecoscentric,redboot-fis-partitions
partition parser to get the correct partition offsets and size. It's
expected that the OEM firmware adjusts the on flash partition table with
the values defined in the image header.

Signed-off-by: Mathias Kresin <dev@kresin.me>

target/linux/gemini/image/Makefile

@@ -45,6 +45,17 @@ define Build/dns313-images
 	rm -rf $@.tmp
 endef
 
+define Build/wiligear-image
+	$(STAGING_DIR_HOST)/bin/mkfwimage2 \
+		-m GEOS -f 0x30000000 -z \
+		-v $(1).v5.00.SL3512.OpenWrt.00000.000000.000000 \
+		-p Kernel:0x020000:0x100000:0:0:$(IMAGE_KERNEL) \
+		-p Ramdisk:0x120000:0x500000:0:0:$@ \
+		-o $@.new
+
+	mv $@.new $@
+endef
+
 # Create the special NAS4220B and Itian Square One SQ201 image
 # format with the squashfs and overlay inside the "rd.gz" file.
 # We pad it out to 6144K which is the size of the initramfs partition.
@@ -143,18 +154,28 @@ define Device/teltonika_rut1xx
 endef
 TARGET_DEVICES += teltonika_rut1xx
 
+# The wiliboard images need some changes to be functional and buildable.
+#
+# The dts would need to use the ecoscentric,redboot-fis-partitions partition
+# parser to get the correct partition offsets and size.
+#
+# The mkfwimage2 call need to be adjusted to reflect the real size of kernel
+# and rootfs. It is expected that the OEM firmware adjusts the on flash
+# partition table with the values defined in the image header.
 define Device/wiliboard_wbd111
 	DEVICE_TITLE := Wiliboard WBD-111
 	DEVICE_DTS := gemini-wbd111
 	KERNEL := kernel-bin | append-dtb | wbd-nops
+	IMAGES := factory.bin
+	IMAGE/factory.bin := append-rootfs | pad-rootfs | wiligear-image "WILI-S.WILIBOARD"
 endef
-TARGET_DEVICES += wiliboard_wbd111
 
 define Device/wiliboard_wbd222
 	DEVICE_TITLE := Wiliboard WBD-222
 	DEVICE_DTS := gemini-wbd222
 	KERNEL := kernel-bin | append-dtb | wbd-nops
+	IMAGES := factory.bin
+	IMAGE/factory.bin := append-rootfs | pad-rootfs | wiligear-image "WILI-S.WBD222"
 endef
-TARGET_DEVICES += wiliboard_wbd222
 
 $(eval $(call BuildImage))