FreeBSD/ppc ABI

[Justin Hibbits]

What's the current FreeBSD/ppc ABI register usage?  I'm writing a
proxy function that messes with some arguments before making the
target function call, and need to know which registers are free for me
to use without having to save argument registers.  From reading the
gcc source it looks like it's a strict SysV R4 ABI, leaving r0, r11,
and r12 available for me to use.  Is this the case, and are there any
others available?

Thanks,

- Justin