[U-Boot] "fdt" commands in extlinux.conf ?

I'd like to enable the CANbus on a Beagle Bone Black (on Fedora ... which doesn't do "cape manager").

The crux is a fdt command in u-boot :

fdt set d_can1 status okay

Is there a way to do this in extlinux.conf ?

I didn't see a way (in uboot 2017.09), so I wrote a uEnv.txt script (see attached).

That's a bit verbose and duplicates a bunch of stuff already in uboot (also : uEnv.txt doesn't exist on my "Orange Pi One").

It there a simpler way to state "fdt" commands ?

Thanks