On Sun, 2010-01-31 at 21:18 -0500, Ralf Baechle wrote: > On Sun, Jan 31, 2010 at 08:55:03AM -0800, Guenter Roeck wrote: > > > > The size of the address space can be probed via CP0 registers (for MIPS > > > architecture processors that is). No need to add any CPU dependencies > > > (except from legacy 64-bit MIPS processors perhaps). > > > > > That would help. Do you happen to know which CP0 register(s) to look for ? > > I browsed through the MIPS 5K and 20Kc manuals, but didn't find it. > > Write a value with all bits set to c0_entryhi, then read it back again. > The set bits in the VPN2 bitfield will indicate the size of the virtual > address range supported. The MIPS64 documentation also calls this value > SEGBITS. The nice thing about this probe is that it is supported for > all 64-bit MIPS processors except the R8000 which has an entirely different > TLB scheme anyway. Are you sure that this doesn't work for the R8000 ? From the user's manual (section 2.1.9, EntryHi) it looks like it should work. Guenter
