+define Build/ubnt-erx-factory-compat
+ echo '21001:6' > $@.compat
+ $(TAR) -cf $@ --transform='s/^.*/compat/' $@.compat
+ $(RM) $@.compat
+endef
+
+define Build/ubnt-erx-factory-kernel
+ if [ -e $(BIN_DIR)/$(KERNEL_INITRAMFS_IMAGE) ]; then \
+ $(TAR) -rf $@ --transform='s/^.*/vmlinux.tmp/' $(BIN_DIR)/$(KERNEL_INITRAMFS_IMAGE); \
+ \
+ md5sum --binary $(BIN_DIR)/$(KERNEL_INITRAMFS_IMAGE) | awk '{print $$1}'> $@.md5; \
+ $(TAR) -rf $@ --transform='s/^.*/vmlinux.tmp.md5/' $@.md5; \
+ $(RM) $@.md5; \
+ fi
+endef
+
+define Build/ubnt-erx-factory-rootfs
+ echo "dummy" > $@.rootfs
+ $(TAR) -rf $@ --transform='s/^.*/squashfs.tmp/' $@.rootfs
+
+ md5sum --binary $@.rootfs | awk '{print $$1}'> $@.md5
+ $(TAR) -rf $@ --transform='s/^.*/squashfs.tmp.md5/' $@.md5
+ $(RM) $@.md5
+ $(RM) $@.rootfs
+endef
+
+define Build/ubnt-erx-factory-version
+ echo '$(BOARD) $(VERSION_CODE) $(VERSION_NUMBER)' > $@.version
+ $(TAR) -rf $@ --transform='s/^.*/version.tmp/' $@.version
+ $(RM) $@.version
+endef
+
+#We need kernel+initrams fit into kernel partition
+define Build/ubnt-erx-factory-check-size
+ @[ $$(($(subst k,* 1024,$(subst m, * 1024k,$(1))))) -ge "$$($(TAR) -xf $@ vmlinux.tmp -O | wc -c)" ] || { \
+ echo "WARNING: Initramfs kernel for image $@ is too big (kernel size: $$($(TAR) -xf $@ vmlinux.tmp -O | wc -c), max size $(1))" >&2; \
+ $(RM) -f $@; \
+ }
+
+ @[ "$$($(TAR) -xf $@ vmlinux.tmp -O | wc -c)" -gt 0 ] || { \
+ echo "WARNING: Kernel for image $@ not found" >&2; \
+ $(RM) -f $@; \
+ }
+endef
+