diff --git a/target/linux/ramips/image/Makefile b/target/linux/ramips/image/Makefile
index 816146ece5..16748b8260 100644
--- a/target/linux/ramips/image/Makefile
+++ b/target/linux/ramips/image/Makefile
@@ -89,6 +89,26 @@ define Build/relocate-kernel
 	rm -rf $@.relocate
 endef
 
+define Build/elx-header
+	$(eval hw_id=$(word 1,$(1)))
+	$(eval xor_pattern=$(word 2,$(1)))
+	( \
+		echo -ne "\x00\x00\x00\x00\x00\x00\x00\x03" | \
+			dd bs=42 count=1 conv=sync; \
+		hw_id="$(hw_id)"; \
+		echo -ne "\x$${hw_id:0:2}\x$${hw_id:2:2}\x$${hw_id:4:2}\x$${hw_id:6:2}" | \
+			dd bs=20 count=1 conv=sync; \
+		echo -ne "$$(printf '%08x' $$(stat -c%s $@) | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
+			dd bs=8 count=1 conv=sync; \
+		echo -ne "$$($(STAGING_DIR_HOST)/bin/mkhash md5 $@ | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
+			dd bs=58 count=1 conv=sync; \
+	) > $(KDIR)/tmp/$(DEVICE_NAME).header
+	$(call Build/xor-image,-p $(xor_pattern) -x)
+	cat $(KDIR)/tmp/$(DEVICE_NAME).header $@ > $@.new
+	mv $@.new $@
+	rm -rf $(KDIR)/tmp/$(DEVICE_NAME).header
+endef
+
 define Build/umedia-header
 	fix-u-media-header -T 0x46 -B $(1) -i $@ -o $@.new && mv $@.new $@
 endef
diff --git a/target/linux/ramips/image/mt7620.mk b/target/linux/ramips/image/mt7620.mk
index 320d4abd1f..36898c99bc 100644
--- a/target/linux/ramips/image/mt7620.mk
+++ b/target/linux/ramips/image/mt7620.mk
@@ -16,25 +16,6 @@ define Build/elecom-header
 		-f $@ -C $(KDIR) v_0.0.0.bin v_0.0.0.md5
 endef
 
-define Build/elx-header
-  $(eval hw_id=$(word 1,$(1)))
-  $(eval xor_pattern=$(word 2,$(1)))
-  ( \
-    echo -ne "\x00\x00\x00\x00\x00\x00\x00\x03" | \
-      dd bs=42 count=1 conv=sync; \
-    hw_id="$(hw_id)"; \
-    echo -ne "\x$${hw_id:0:2}\x$${hw_id:2:2}\x$${hw_id:4:2}\x$${hw_id:6:2}" | \
-      dd bs=20 count=1 conv=sync; \
-    echo -ne "$$(printf '%08x' $$(stat -c%s $@) | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
-      dd bs=8 count=1 conv=sync; \
-    echo -ne "$$($(STAGING_DIR_HOST)/bin/mkhash md5 $@ | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
-      dd bs=58 count=1 conv=sync; \
-  ) > $(KDIR)/tmp/$(DEVICE_NAME).header
-  $(call Build/xor-image,-p $(xor_pattern) -x)
-  cat $(KDIR)/tmp/$(DEVICE_NAME).header $@ > $@.new
-  mv $@.new $@
-endef
-
 define Device/aigale_ai-br100
   MTK_SOC := mt7620a
   IMAGE_SIZE := 7936k
diff --git a/target/linux/ramips/image/mt7621.mk b/target/linux/ramips/image/mt7621.mk
index 644f984197..4cf9cf7ff2 100644
--- a/target/linux/ramips/image/mt7621.mk
+++ b/target/linux/ramips/image/mt7621.mk
@@ -30,25 +30,6 @@ define Build/elecom-wrc-factory
   mv $@.new $@
 endef
 
-define Build/elx-header
-  $(eval hw_id=$(word 1,$(1)))
-  $(eval xor_pattern=$(word 2,$(1)))
-  ( \
-    echo -ne "\x00\x00\x00\x00\x00\x00\x00\x03" | \
-      dd bs=42 count=1 conv=sync; \
-    hw_id="$(hw_id)"; \
-    echo -ne "\x$${hw_id:0:2}\x$${hw_id:2:2}\x$${hw_id:4:2}\x$${hw_id:6:2}" | \
-      dd bs=20 count=1 conv=sync; \
-    echo -ne "$$(printf '%08x' $$(stat -c%s $@) | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
-      dd bs=8 count=1 conv=sync; \
-    echo -ne "$$($(STAGING_DIR_HOST)/bin/mkhash md5 $@ | fold -s2 | xargs -I {} echo \\x{} | tr -d '\n')" | \
-      dd bs=58 count=1 conv=sync; \
-  ) > $(KDIR)/tmp/$(DEVICE_NAME).header
-  $(call Build/xor-image,-p $(xor_pattern) -x)
-  cat $(KDIR)/tmp/$(DEVICE_NAME).header $@ > $@.new
-  mv $@.new $@
-endef
-
 define Build/iodata-factory
   $(eval fw_size=$(word 1,$(1)))
   $(eval fw_type=$(word 2,$(1)))