Hi Scott,
You could even make it a weak symbol that stays at NULL, so any attempt to call it will trap that way (assuming NULL pointers are trapped in U-Boot on that architecture...).
As you know, they are not.
If you're happy with not making it debuggable, then there's no need to trap on the NULL -- just make sure it never happens. :-)
I'd much rather spend the handful of bytes on at least a __builtin_trap(), though.
I also think that making our lifes easier is a very good thing. Our "it's only a bootloader" codebase is pretty complex already so I welcome making it more robust. I was kind of surprised the other day that null-pointer jumps(*) did not result in immediate "bad programmer, no cookie this time" messages but in random crashes.
Cheers Detlev
(*) well, actually they were jumps to _relocated_ NULL pointers, but still ;)