[U-Boot] uboot fdt commands

Hi

This question is regarding to uboot commands

I use the uboot "fdt mknode" command to create two nodes as below

uboot> fdt resize

uboot> fdt mknode /my_light_pinctrl

uboot> fdt set /my_light_pintrl fsl,pins <1 2 3 4 5 6>

uboot> fdt mknode /my_light

uboot> fdt /my_light pinctrl-names default

uboot> fdt /my_light pinctrl-0 <asign to my_light_pinctrl>

but I don't know to write and get the last line working in uboot, because I don't know the phandle of the newly created node "my_light_pinctrl".

Can someone help?

Cheers,