Help with Ruckus AP

Hi everyone, I don't know if this is the right place to ask, but I have some Ruckus APs and I'd like to find a way to boot the stock firmware via tftp. By googling I found a tutorial for booting openwrt:

ath79: support Ruckus ZoneFlex 7351

So I tried to enter the following command:

u-boot> setenv bootcmd "bootm 0xbf040000"
u-boot> saveenv
u-boot> tftpboot 0x81000000 ZF7352_104.0.0.0.1347.bl7
u-boot> bootm 0x81000000

The AP does not start as expected and returns the following error message:

## Booting image at 81000000 ...
Bad Magic Number

Is there anyone familiar with Ruckus give me any tips?
@Leo-PL

If you want to load stock image, you should not overwrite stock bootcmd - so clear it first. Instead, flashing the stock image in the right offset (where first OS image starts) over TFTP should help you get going - or: load OpenWrt initramfs, and then flash the stock image to firmware partition from within OpenWrt.