[yocto] Command to make zimage to ramdisk format

[JH]

Hi,

I built the Yocto images:

dev-image-20190528085324.rootfs.wic.gz
zImage--xxxx.bin

I need to build zImage to ramdisk to run it on RAM in development.
What is the correct mkimage command can be used for add ramdisk to the
zimage?

$ mkimage -A arm -T ramdisk -C none -n uInitrd -d /path/to/initrd.img
/path/to/uInitrd

Thank you.

Kind regards,

- JH