On Sun, Apr 08, 2001 at 06:42:41PM -0400, John Tobey wrote: > The CPU is a QED RM5231 (CONFIG_NEVADA) 150MHz. May I assume that > nobody has run a 64-bit kernel on this thing? The RaQ has no video > card but a serial console, PCI, IDE, Ethernet, and special LEDs, panel > buttons, and LCD display. If I can get a 64-bit kernel to boot and > prove its existence through any of these devices, I will be drunk with > power. So far the only supported machine by the mips64 kernel is the SGI Origin 200 / 2000 series. > The reason I want 64 bits is that I (a) want a challenge, (b) plan to > write an application that uses a sparse address space (40 bits is > better than 31), (c) plan to outlive the 31-bit time_t, and (d) am > p.o.ed at having bought the thing based on misleading advertising that > mentioned a 64-bit processor but not the 32-bit OS. > Big/little endian macht nichts. I guess big will be easier, and I'm > not concerned with running any existing 32-bit binaries. Go for little endian because the firmware is little endian; supporting ``other-endian'' for userspace would be unecessary extra pain. We already have suport for 32-bit binaries in the 64-bit kernel; in fact ALL software we run on 64-bit kernels is 32-bit. 32-bit wasn't only the easy thing to do - it's also the more efficient thing for most software which doesn't need 64-bit registers or 64-bit address space. For a system with a dog slow 32-bit memory bus such as the Qube 64-bit kernels would mean a dramatic slowdown. I admit it's interesting though, mostly for engineering reasons, not as a platform. > I imagine that I would start by grafting Cobalt's peripheral support > code from arch/mips/cobalt (now defunct) and include/asm-mips/cobalt.h > into the mips64 tree from cvs@oss.sgi.com:/cvs/linux. Somebody else was already working on upgrading the Cobalt kernel to 2.4. Ralf
