Booting on a Powerbook6,8 (was Re: Installing 8.0 on a Powerbook6,8)

[Jason Thorpe <thorpej%me.com@localhost>]

Thread bump.

> On Mar 23, 2019, at 5:40 PM, Jason Thorpe <thorpej%me.com@localhost> wrote:
> 
> 
> 
>> On Mar 20, 2019, at 1:57 AM, Valery Ushakov <uwe%stderr.spb.ru@localhost> wrote:
>> 
>> On Wed, Mar 20, 2019 at 08:24:41 +0100, Martin Husemann wrote:
>> 
>>> On Wed, Mar 20, 2019 at 01:24:59AM -0400, Michael wrote:
>>>> First, did you try -current? uwe@ fixed a bug in ofwboot which caused
>>>> this kind of symptoms on Minis.
>>> 
>>> Can you please file a pullup request for that? I only see the fix for 
>>> port-macppc/53727.
>> 
>> This is probably http://gnats.netbsd.org/44895 though I did NOT enable
>> the fix.
> 
> I built ofwboot locally with the change.  I have to do the dance do the "1 1f lshift not dec!" dance to get past the decrement exception, but I still end up with "Invalid memory access at   %SRR0: 00000000 %SRR1: 00083030".  Doesn't matter if I load ofwboot.elf or ofwboot.xcf.

So, update on this.

My Powerbook6,8 is still struggling.  But it's been easier to make progress with it since I managed to dig out an old Leopard install DVD sitting in a long-forgotten box so I can at least boot *something* on it to move files around.  Using a bone-stock 9.1 boot loader and a -current kernel, I've made some progress tracking the problem down:

- Our ofwboot.elf seems to be fine, in that I was able to use it to boot an OpenBSD 6.8 kernel on this machine.  I suspect ofwboot.xcf would work just fine, too.

- I have determined that we do make it into the kernel.  It's blowing up in ofw_machdep.c:mem_regions(), called from oea_batinit(), called from ofwoea_batinit(), called from ofwoea_initppc(), called from initppc().

- Specifically, it blows up on the call to OF_finddevice("/memory").  But this is after a successful call to OF_finddevice("/") and two successful calls to OF_getprop() (to get #address-cells and #size-cells).

The /memory node does exist in OFW, and reflects two memory regions:

    00000000 10000000
    10000000 40000000

(It has a 1GB PC2700 DIMM in addition to the built-in 256MB built-in.)

-- thorpej