DB120: in build with kernel, patch-cmdline and lzma one kernel file, but mkimage another kernel file?

I pull the newest source code today, make menuconfig to ar9344 DB120, and then download to my board, but it's error. It use uboot cmdline, but my uboot cmdline have some error. What should i do, if i want to use cmdline from openwrt config files"target linux ar71xx image/Makefile".

The old openwrt version is ok with DB120, the new one make the config files no effect.

I have make kernel do not use uboot cmdline like this:

arch/mips/kernel/setup.c:
#if 0
if ((USE_PROM_CMDLINE && arcs_cmdline[0]) ||
(USE_DTB_CMDLINE && !boot_command_line[0]))
strlcpy(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE);

if (EXTEND_WITH_PROM && arcs_cmdline[0]) {
	if (boot_command_line[0])
		strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
	strlcat(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE);
}

#endif

I add something in target/linux/ar71xx/image/generic.mk like:

define Device/DB120
  DEVICE_TITLE := Atheros DB120 reference board
  BOARDNAME := DB120
  IMAGE_SIZE := 7744k
  CONSOLE := ttyS0,115200
  DEVICE_PACKAGES := kmod-usb-core kmod-usb2 kmod-usb-storage
  MTDPARTS := spi0.0:256k(u-boot)ro,64k(u-boot-env)ro,6336k(rootfs),1408k(kernel),64k(nvram),64k(art)ro,7744k@0x50000(firmware)
  CMDLINE = board=DB120 console=ttyS0,115200 mtdparts=spi0.0:256k(u-boot)ro,64k(u-boot-env)ro,6336k(rootfs),1408k(kernel),64k(nvram),64k(art)ro,7744k@0x50000(firmware)
endef
TARGET_DEVICES += DB120

But, no effect......

patch-cmdline with [build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin],
and lzma with [build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin] too,
but mkimage with [build_dir/target-mips_24kc_musl/linux-ar71xx_generic/vmlinux.bin.lzma], and result in bin/targets/ar71xx/generic/openwrt-ar71xx-generic-uImage-lzma.bin?
I think here must be something wrong, please pay attention.

Here is new source code build log:

rm -f /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin
cp /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/vmlinux /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin
/LEDE/openwrt/staging_dir/host/bin/patch-cmdline /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin 'board=DB120 console=ttyS0,115200 mtdparts=spi0.0:256k(u-boot)ro,64k(u-boot-env)ro,6336k(rootfs),1408k(kernel),64k(nvram),64k(art)ro,7744k@0x50000(firmware)'
search space used is default of 16KB
/LEDE/openwrt/staging_dir/host/bin/lzma e /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin -lc1 -lp2 -pb2  /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/DB120-kernel.bin.new
cp /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/vmlinux /LEDE/openwrt/bin/targets/ar71xx/generic/openwrt-ar71xx-generic-vmlinux.bin
dd if=/LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/vmlinux.bin.lzma of=/LEDE/openwrt/bin/targets/ar71xx/generic/openwrt-ar71xx-generic-vmlinux.lzma bs=65536 conv=sync
21+1 records in
22+0 records out
1441792 bytes (1.4 MB) copied, 0.00115289 s, 1.3 GB/s
mkimage -A mips -O linux -T kernel -a 0x80060000 -C lzma  -e 0x80060000 -n 'MIPS OpenWrt Linux-4.9.77' -d /LEDE/openwrt/build_dir/target-mips_24kc_musl/linux-ar71xx_generic/vmlinux.bin.lzma /LEDE/openwrt/bin/targets/ar71xx/generic/openwrt-ar71xx-generic-uImage-lzma.bin
Image Name:   MIPS OpenWrt Linux-4.9.77
Created:      Wed Jan 24 16:05:15 2018
Image Type:   MIPS Linux Kernel Image (lzma compressed)
Data Size:    1379038 Bytes = 1346.72 kB = 1.32 MB
Load Address: 80060000
Entry Point:  80060000

And here is old source code build log:

staging_dir/host/bin/patch-cmdline build_dir/linux-ar71xx_generic/tmp/vmlinux-db120 "board=DB120 console=ttyS0,115200 mtdparts=spi0.0:256k(u-boot)ro,64k(u-boot-env)ro,6336k(rootfs),1408k(kernel),64k(nvram),64k(art)ro,7744k@0x50000(firmware)"
staging_dir/host/bin/lzma e /build_dir/linux-ar71xx_generic/tmp/vmlinux-db120 -lc1 -lp2 -pb2  build_dir/linux-ar71xx_generic/tmp/vmlinux-db120.bin.lzma


mkimage -A mips -O linux -T multi -a 0x80060000 -C lzma  -e 0x80060000 -n 'MIPS OpenWrt Linux-3.3.8' -d build_dir/linux-ar71xx_generic/tmp/vmlinux-db120.bin.lzma build_dir/linux-ar71xx_generic/tmp/vmlinux-db120.uImage
Image Name:   MIPS OpenWrt Linux-3.3.8
Created:      Tue Jan  9 13:08:00 2018
Image Type:   MIPS Linux Multi-File Image (lzma compressed)
Data Size:    1003583 Bytes = 980.06 kB = 0.96 MB
Load Address: 80060000
Entry Point:  80060000

Use bin/targets/ar71xx/generic/openwrt-ar71xx-generic-db120-squashfs-sysupgrade.bin is OK.
Use bin/targets/ar71xx/generic/openwrt-ar71xx-generic-root.squashfs and bin/targets/ar71xx/generic/openwrt-ar71xx-generic-uImage-lzma.bin is not OK.

Does newest version only support rootfs+kernel together, not support single rootfs and single kernel?