[parisc-linux] 720 - some progress

[Jochen Friedrich]

Hi Jurij,

> And another (very weird) thing... I've manually decoded the instruction
> (036008A4), which produces the trap 11 (hopefully, correctly :-).
> It turns out to be an MFCTL instruction to load contents of control
> register 27 into a general register 4.

The CPU in the 720 will treat this as a priviledged instruction. The
changes "signal 18 -> signal 26, signal 27, signal 28" and "allow read
access to CR26 and CR27 for non-priviledged access" are documented as new
for the PA7100LC processor, so they are not available in the 720.

Another thing to emulate on the old 720/50 platform...

Cheers,
Jochen