Re: original iMac problems

["John D. Baker" <jdbaker%mylinuxisp.com@localhost>]

On Thu, 5 Jul 2012, John D. Baker wrote:

> The other problem is that at some point between netbsd-4 and netbsd-5,
> attaching atabus* hangs the system hard.  I've completed the first two
> iterations of bisection as follows:
>
> 21-Sep-2007 0000Z (4.99.31) works
> 21-Apr-2008 0000Z (4.99.60) hangs
>
> Currently rolling sources back to 27-Jan-2008 0000Z and will try again.

27-Jan-2008 0000Z (4.99.50) hangs
17-Oct-2007 0000Z (4.99.34) works
ppcoea-renovation branch is merged
18-Oct-2007 0000Z (4.99.34) probes atabus* but panics after probing
                            genfb0:

genfb0 at pci0 dev 10 function 0: ATI Technologies 3D Rage Pro
panic: no width property
Stopped in pid 0,1 (system) at  netbsd:cpu_Debugger+0x10:         lwz      r0, 
r1, 0x14
db>

At this stage, the keyboard doesn't work, so the only way out is to
poke the reset switch...

(I'm booting a kernel which simply includes GENERIC and turns on various
debugging options and explicitly excludes non-working display devices
(machfb in my case).  As with DDB, userconf lacks a working keyboard,
so devices can't be disabled at runtime in a normal GENERIC kernel.)

Rebuilding the kernel with only "ofb" provides output and shows the
system hanging as documented at length in a number of prior threads in
this list.

The kernel continues enumerating devices for some time after probing
atabus[01] at wdc[01], finally hanging after printing:

  scsibus0: waiting 2 seconds for devices to settle.

This indicates that somewhere in the mass of changes merged from the
"ppcoea-renovation" branch is the one that broke atabus (atapibus?)
support on first-generation iMacs...

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