Tightening kernel for Mac Mini G4

[Justin Hibbits]

On Thu, 23 Jan 2014 04:49:22 +0000
Alexey Dokuchaev <danfe at FreeBSD.org> wrote:

> On Wed, Jan 22, 2014 at 08:25:42AM -0800, Justin Hibbits wrote:
> > ata_macio and ata_kauai aren't available as modules.  It's probably
> > trivial to make them such, but currently they're not.  Just keep the
> > devices in kernel config.
> 
> OK, I can live with "device ATA" for a while; but ultimately I do
> think that ata_macio and ata_kauai should be factored out as modules
> (similar with our existing x86 ata stuff).  Ideally, all
> hardware-dependent stuff should be modular.

That shouldn't be too difficult.  Just needs someone to take the time
to do it.

> > Neither of these are necessary for you.  I should probably
> > eventually modularize windtunnel driver (and give it a better
> > name).  SMU is for G5 systems, PMU is for G4 and G3 systems.
> 
> Great, I've removed entire "Misc" section of the config.  I'm
> wondering if I can do the same for ADB support?  There are no ADB
> connectors for peripherals on Mac Mini; is ADB still required (used
> internally)?  All three devices (adb, cuda, pmu) or something can be
> dropped out?

ADB is unnecessary, as is cuda.  PMU isn't strictly necessary, but I'm
in the process of adding more capabilities to our PMU driver, so you
may want to keep it, but it's not required for operation.

> > Can you drop the output of 'ofwdump -ap' somewhere (freefall?) and I
> > can take a look at it.  Internal sound on most PowerPC Apple
> > hardware is supported, I'm curious why yours isn't.
> 
> Sure, have a look: ~danfe/macmini-g4-ofw.dump.

Looks like you don't have 'codec' node, so mixer likely will be
software only.  Someone else may know what to do for the sound chip
(compatible= 'AOAKeylargo', only a 'sound' node, I've never seen that
one before).  It may be simple to implement, but I'm not certain.  USB
audio should work fine, though.

> 
> ./danfe
> 
> P.S.  "make -j2 buildworld" on tmpfs-backed OBJDIR took 12 hours
> (default -CURRENT, i.e. reduced performance) and used 1,2G of tmpfs
> (and 76% of 1G swap).  Replacing default 256M of RAM with 1G module
> was definitely a good idea.  Alas, "make buildkernel" (without
> cleaning after buildworld) caused it to run out of memory. :(

Yeah, buildworld is a beast.  I think on my dual 1.42GHz G4 w/ 2GB RAM,
a buildworld+buildkernel takes 8 hours with -j4.  I suggest not
building clang, it's not complete yet for ppc32 (it's complete for
ppc64, but there are some bugs rdivacky is tracking down, I'm helping
off and on).

- Justin