diff --git a/include/image-commands.mk b/include/image-commands.mk
index 83ecf7c520..f2c3f76f91 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -438,6 +438,20 @@ define Build/kernel2minor
 	rm -f $(temp_file)
 endef
 
+define Build/yaffs-filesystem
+	let \
+		kernel_size="$$(stat -c%s $@)" \
+		kernel_chunks="(kernel_size / 1024) + 1" \
+		filesystem_chunks="kernel_chunks + 3" \
+		filesystem_blocks="(filesystem_chunks / 63) + 1" \
+		filesystem_size="filesystem_blocks * 64 * 1024" \
+		filesystem_size_with_reserve="(filesystem_blocks + 2) * 64 * 1024"; \
+		head -c $$filesystem_size_with_reserve /dev/zero | tr "\000" "\377" > $@.img \
+		&& yafut -d $@.img -w -i $@ -o kernel -C 1040 -B 64k -E -P -S $(1) \
+		&& truncate -s $$filesystem_size $@.img \
+		&& mv $@.img $@
+endef
+
 define Build/kernel-bin
 	rm -f $@
 	cp $< $@
diff --git a/target/linux/ath79/image/common-mikrotik.mk b/target/linux/ath79/image/common-mikrotik.mk
index b37c8b7197..94c29d8cb6 100644
--- a/target/linux/ath79/image/common-mikrotik.mk
+++ b/target/linux/ath79/image/common-mikrotik.mk
@@ -10,7 +10,7 @@ endef
 define Device/mikrotik_nor
   $(Device/mikrotik)
   DEVICE_PACKAGES := -yafut
-  IMAGE/sysupgrade.bin := append-kernel | kernel2minor -s 1024 -e | \
+  IMAGE/sysupgrade.bin := append-kernel | yaffs-filesystem -M | \
 	pad-to $$$$(BLOCKSIZE) | append-rootfs | pad-rootfs | \
 	check-size | append-metadata
 endef
diff --git a/target/linux/ipq40xx/image/mikrotik.mk b/target/linux/ipq40xx/image/mikrotik.mk
index f0e1f1aad3..8c2c6fa08e 100644
--- a/target/linux/ipq40xx/image/mikrotik.mk
+++ b/target/linux/ipq40xx/image/mikrotik.mk
@@ -5,7 +5,7 @@ define Device/mikrotik_nor
 	KERNEL_NAME := vmlinux
 	KERNEL := kernel-bin | append-dtb-elf
 	IMAGES = sysupgrade.bin
-	IMAGE/sysupgrade.bin := append-kernel | kernel2minor -s 1024 | \
+	IMAGE/sysupgrade.bin := append-kernel | yaffs-filesystem -L | \
 		pad-to $$$$(BLOCKSIZE) | append-rootfs | pad-rootfs | \
 		check-size | append-metadata
 endef
diff --git a/target/linux/ramips/image/mt7621.mk b/target/linux/ramips/image/mt7621.mk
index 8886456bbb..0643cd29f4 100644
--- a/target/linux/ramips/image/mt7621.mk
+++ b/target/linux/ramips/image/mt7621.mk
@@ -1770,7 +1770,7 @@ define Device/MikroTik
   DEVICE_PACKAGES := kmod-usb3 -uboot-envtools
   KERNEL_NAME := vmlinuz
   KERNEL := kernel-bin | append-dtb-elf
-  IMAGE/sysupgrade.bin := append-kernel | kernel2minor -s 1024 | \
+  IMAGE/sysupgrade.bin := append-kernel | yaffs-filesystem -L | \
 	pad-to $$$$(BLOCKSIZE) | append-rootfs | pad-rootfs | check-size | \
 	append-metadata
 endef
diff --git a/tools/Makefile b/tools/Makefile
index f60a458f98..f4e749d710 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -83,6 +83,7 @@ tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_TARGET_mxs),y) += elftosb sdim
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_TARGET_realtek),y) += 7z
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_TARGET_tegra),y) += cbootimage cbootimage-configs
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_USES_MINOR),y) += kernel2minor
+tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_USES_MINOR),y) += yafut
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_USE_SPARSE),y) += sparse
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_USE_LLVM_BUILD),y) += llvm-bpf
 tools-$(if $(CONFIG_BUILD_ALL_HOST_TOOLS)$(CONFIG_USE_MOLD),y) += mold
@@ -130,6 +131,7 @@ $(curdir)/sdcc/compile := $(curdir)/bison/compile
 $(curdir)/squashfs3-lzma/compile := $(curdir)/lzma-old/compile
 $(curdir)/squashfs4/compile := $(curdir)/xz/compile $(curdir)/zlib/compile
 $(curdir)/util-linux/compile := $(curdir)/bison/compile
+$(curdir)/yafut/compile := $(curdir)/cmake/compile
 
 ifneq ($(HOST_OS),Linux)
   $(curdir)/coreutils/compile += $(curdir)/automake/compile $(curdir)/bison/compile $(curdir)/gnulib/compile