[9fans] Loongson port, and 64 bit MIPS

[cherry <lunaria21@gmail.com>]

Hello 9Fans,

I just got a Loongson 2F machine (Yeeloong 8089A laptop) (MIPS LE), so
I extended my previous Loongson 2E port (32 bit) to run on it. Now
both machines can run Plan 9. Specific to 2F laptop, the keyboard,
mouse, screen and ethernet are supported. The hard drive is supported
only on 2E. USB does not work yet on either machine. And for the
userland of MIPS LE, all the commands built and seem to work okay,
including acme and page. If anybody interested, check it out at
https://bitbucket.org/cherry9/plan9-loongson
(lucio, is it the same machine as yours?)

Currently the 2F kernel specific bits are kept in a separated
directory. It is quite similar to 2E but I haven't tried to unify both
kernels. Bind it before the 2E sources to use it.

As a separated message, upon minux's request, I started to look into
64 bit MIPS. Both 2E and 2F machines are 64 bit, though R4000-ish, not
standard MIPS64. Currently I build the compiler, 4c, based on the old
one from /n/sources/contrib/tim, now at
https://bitbucket.org/cherry9/4c

With this compiler, the 64 bit kernel is in progress. For now, it
boots on my 2E machine, with serial console only. I haven't got time
to look into any device drivers. PCI space is 32 bit... Will do it
ASAP.

Hope this message is useful.

Thanks,
-cherry