Booting Imac G5

J. Mayer l_indien at
Mon Nov 15 23:45:07 EST 2004

On Mon, 2004-11-15 at 10:26, Segher Boessenkool wrote:
> >> - Ethernet PHY failure if the cable is plugged
> >>   during boot
> >
> > Ok, have to check out what's in darwin, there are some bits for the
> > Shasta chipset that I haven't adapted yet.
> The PHY is sort-of new (it's on the Vesta chip).
> >> - No RTC
> >
> > RTC is probably in the SMU...
> It is.

Apple say it's an external RTC in the developper notes. The problem is
to get an I2C driver for the SMU. With the forth code, seems that it can
be made ;-)

> >> - Lot's of segfaults occuring when multiple
> >>   concurent processes are running, especially
> >>   during compilations. Maybe the RAM is bad
> >>   (I'm trying to port memtest86 to check this)
> >>   or the CPU state is not completely saved /
> >>   restored when rescheduling: it seems not
> >>   to occur when compiling without doing
> >>   anything else concurently.
> >>
> >> Do you have any idea about the last point ? Could this be Altivec
> >> context save / restore problems ?
> >
> > I very much doubt it has anything to do with CPU context
> > saving/restoring... Could be lots of different things, difficult to say
> > at this point. Thermal problem ? Clock chip setup problem ? Bad
> > RAMs ? ...
> Doesn't sound like a hardware problem, as it only occurs if he is
> running multiple processes...

I checked my RAM during more than two hours: I ran a memory checker I
did, based on memtest86, which locks the more memory it can and test it
in a loop. I did a standalone program, not using the libc, launched by a
size-reduced Linux kernel (~1MB of code). So, I've been able to check
480 MB of RAM (I got 512 MB)  without any fault. Each test suite took
about 20 minutes, and it ran 7 times before I stopped it. As I get a lot
of segfaults when compiling, I can't believe it's a hardware
CPU/cache/RAM problem and no problem occured at least once during the
memory check.

> Or maybe it is...  try running without X?

I can hardly run X. I can launch it but it's not really usable as
forking to launch xterms,..., make it crash quickly.
I mainly use the Imac via ssh for now...

J. Mayer <l_indien at>
Never organized

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