SGI O2 systems can use the rare RM5200 CPU board (Nevada).  Building the kernel 
with RM52xx selected, will however, cause an ARCS Exception at bootup because 
the kernel was built with cpu_has_llsc defined.

Changing the macro check in asm-mips/mach-ip32/cpu-feature-overrides.h to check 
for both CPU_R5000 or CPU_NEVADA and CPU_64BIT will fix the issue by defining 
cpu_has_llsc to 0.  The patch below does this, allowing an RM52xx kernel to be 
booted on SGI O2 systems.  It also allows such a CPU to be selected in 
menuconfig on O2 as well.


--Kumba

-- 
Gentoo/MIPS Team Lead
Gentoo Foundation Board of Trustees

"Such is oft the course of deeds that move the wheels of the world: small hands 
do them because they must, while the eyes of the great are elsewhere."  --Elrond