Performance instrumentation registers

[raymond.meyer%rambler.ru@localhost]

On UltraSPARC II there are 2 performance instrumentation registers:

Performance Control Register (PCR), and
Performance Instrumentation Counter (PIC)

PIC is a 64-bit register, divided into two 32-bit counters D1 and D0.
Issuing the following assembly instruction aborts the program with
'Illegal instruction':

        rd %pic, %l0

So I think the PRIV bit in PCR register is set to 1, which forbids
userland access to PIC register. Any ideas how I can unset that bid? Do
I need to hack NetBSD kernel or there is a way to load a small program
in kernel space to unset the bit?