Sir FAQ Master, and other esteemed viewers, I may have found a cause of the lockups. I was tracking down the "jiffies" issue, and noticed a Hugo-ism in the kernel timer code, where he has some code which he says must run uninterruptable to reset the jiffie timer.. but the code fails to mask FIRQ's.

It's a single-character fix, and I'll put it out in v222 later today.

Of course, this is all just theory, so.. from v222 onwards, if you ever experience a lockup with Hijack, let me know.

In the meanwhile, does anyone recall exactly what FIRQs are used for on the RioCar (Mk2a)?

-ml