[9fans] Go (again) on plan9/arm

[lucio@proxima.alt.za]

Gorka has made good progress with his port of Go, his implementation
on the Raspberry PI tests to completion and only a few tests are
failing.  The outstanding failures are being investigated and will
be corrected.

On the Sheevaplug the problem is a bit more complicated.  Gorka and I
are in perfect (if there is such a state) synchronisation regarding
the Go sources: we are presently working with a copy of the "tip" Hg
release onto which CL 7987044 has been applied.  The description in
the CL goes into details regarding additional adjustments required,
but is silent about the nature of the changes that were needed to the
Plan 9 distribution.

Given that Gorka and I are working on different ARM platforms, it is
not surprising that on my side testing is not as successful.  On the
one hand, there may still be issues in the Go sources, but it is also
very difficult to synchronise the Plan 9 installations and at this
point I don't know what differences there may be in there.

We are expecting a release from Bell Labs of Plan 9 with 21-bit runes
replacing the current 16-bit version.  This is big and difficult and
almost certainly extremely painful, so I doubt it will be completed
quickly (feel free to surprise me, guys!).  I noticed some changes
being applied today, I think Geoff and Co. are approaching the problem
circumspectly and, this is my guess, by making adjustments that can be
kept self-contained.  I do wish them speedy success.

In the meantime, I'd like some 9fans who may own a Sheevaplug,
possibly also other ARM equipment supported by Plan 9 - 9fans with
some interest in Go - to try to install Go on their devices.  The
instructions are detailed in "codereview" CL 7987044, see the Go
documentation on how to contribute for guidelines.  Briefly, the idea
is to clone the "tip" (default) Go development tree and build it
_after_ applying CL 7987044 as a patch.  To the best of my knowledge,
"make.rc" will build the Go distribution and "run.rc --no-rebuild"
will run the tests.

Ideally, I'm looking for a breakthrough with a pristine Plan 9
distribution.  This would require building the ARM (5?) development
toolchain, then the entirety of the runtime for the ARM as well as the
appropriate kernel(s).  I guess the interested parties already know
this, as well as how to boot the ARM equipment with the most recent
available ARM kernel.

There are additional changes that must be applied to the Plan 9
distribution before we approach a successful Go build (the build is
easier, but the Go runtime needs a good few changes).  The idea would
be, in parallel with Bell Labs proceeding on their own path, to
identify the changes that are absolutely critical and document them so
that we can have Go running without putting undo pressure on Bell
Labs.

I'm keen to coordinate these efforts, but Gorka, Richard Miller and
Ron Minnich may also want to participate and/or lead; I am not
volunteering their involvement, I merely mention those I know have the
interest and knwoledge to take part.  There are quite a few others and
they are welcome to introduce themselves if they want to be involved.
I can't offer the same code review infrastructure as Go does, but I
believe that coreboot.org has a similar system - that's outside my
realm and each party may want to specify what rules apply to them.

I hope I'm not treading on any sensitive toes this time.

Lucio.