For those of you following at home:
I finally bit the bullet and made a dozen trips between my 4th-floor apartment and my car, because I could use the exercise. I've finally gotten scripts to run on my phatbox (ie like several of the rest of you...)
If I had paid more attention to judb's kernel oops messages, I would have noticed something odd ... the part where the program dies is in malloc, when the program starts up, before it actually does anything. That's why there's no output.
I think it might be because I didn't explicitly compile glibc / readrom with -mcpu=arm7tdmi -- which I think is as close as we're going to get. At least I hope so ... it will take another hour or two for me to recompile gcc + glibc.
*sigh*
But the good news is that it wasn't the fact we're using mmap.
Ben