make kernel error

#1

MKIMAGE arch/arm64/boot/dts/rockchip/overlay/rockchip-fixup.scr
/bin/sh: 1: mkimage: not found
scripts/Makefile.lib:343: recipe for target ‘arch/arm64/boot/dts/rockchip/overlay/rockchip-fixup.scr’ failed
make[3]: *** [arch/arm64/boot/dts/rockchip/overlay/rockchip-fixup.scr] Error 127
scripts/Makefile.build:484: recipe for target ‘arch/arm64/boot/dts/rockchip/overlay’ failed
make[2]: *** [arch/arm64/boot/dts/rockchip/overlay] Error 2
scripts/Makefile.build:484: recipe for target ‘arch/arm64/boot/dts/rockchip’ failed
make[1]: *** [arch/arm64/boot/dts/rockchip] Error 2
arch/arm64/Makefile:127: recipe for target ‘dtbs’ failed
make: *** [dtbs] Error 2

#2

which tool did you use to compile?