[U-Boot] U-boot && forth kernel

Hello to all!

We are developing various IP-blocks for sparc' system-on-chip's. I have successfully ported u-boot to our board (it was not too hard, thanks!) , but now there is an idea to run some FORTH-kernel for testing and debugging purposes without any OS. I tried OpenBIOS software, but without luck. So my question is - does anyone have an experience of launching FORTH as u-boot application?

Thanks, Sergey