booting/loading a tool, not kernel

[Andriy Gapon]

I'd like to add an entry to my loader menu to load/execute memtest86
instead of a kernel. It is built as standalone ELF executable, of course.
Currently I go to a loader prompt and do:
> unload
> load /boot/memtest86
> boot

Where should I look to get this into the forth code?

Suppose I want to extend this approach.
What would be a good name for subdirectory to put such tools?
What would be a good way to add a sub-menu for such tools?

Also, my current approach means that loader still first loads a standard
kernel and its modules and then replaces them with memetest86. How to
get to a loader menu without pre-loading anything?

-- 
Andriy Gapon