Failed attempt to boot a (non-debug) head -r339076 on an old PowerMac G5 "Quad Core" (built via devel/powerpc64-gcc): Waking up CPU 1

[Andreas Tobler]

On 09.10.18 22:35, Mark Millard via freebsd-ppc wrote:
> [Reverting head -r334498 in my head -r339076 context was enough to get
> the G5 so-called "Quad Core" to boot just fine as a variant of
> -r339076 .]
> 
> On 2018-Oct-9, at 12:54 PM, Mark Millard <marklmi at yahoo.com> wrote:
> 
>> On 2018-Oct-9, at 8:20 AM, Mark Millard <marklmi at yahoo.com> wrote:
>>
>>> [The stable/head mix seems to be a wrong idea: 11.2 gets past
>>> the SMP: messages just fine on the so-called G5 "Quad Core".]
>>>
>>> On 2018-Oct-8, at 5:14 PM, Mark Millard <marklmi at yahoo.com> wrote:
>>>
>>>> On 2018-Oct-8, at 1:27 PM, Justin Hibbits <chmeeedalf at gmail.com> wrote:
>>>>
>>>>>> . . .
>>>>>
>>>>> It would be helpful to know the last known-good SVN revision, both for
>>>>> Head and 11.x, as well as the oldest failing one.  Since my G5 bit the
>>>>> dust, I can't check locally.
>>>>
>>> . . .
>>
>> There are examples of head's kernels that sometimes
>> fail to get to the "SMP:" messages and sometimes work
>> for getting there (and beyond). So:
>>
>> My reporting any example failure is a solid indicator
>> of the "does not reach "SMP:" problem in that build.
>> (All tries reached the waking message on at least cpu
>> 1.)
>>
>> My reporting "worked" for a revision might be a
>> misclassification. (This makes for a messier
>> "binary-like search".)
>>
>> That said, the summary of the later detail is:
>>
>> head -r334494 kernel worked
>> head -r334528 kernel failed
>>
>> (There is nothing between those for:
>>
>> https://artifact.ci.freebsd.org/snapshot/head/r*/powerpc/powerpc64/kernel.txz
>>
>> so getting a smaller range requires builds.
>> I've not attempted that.)
>>
>> The only machine-dependent powerpc64 change between
>> those 2 that I see is:
>>
>> Author: jhibbits
>> Date: Fri Jun  1 21:37:20 2018
>> New Revision: 334498
>> URL:
>> https://svnweb.freebsd.org/changeset/base/334498
>>
>>
>> Log:
>>   Increase powerpc64 KVA from ~7.25GB to 32GB
>> . . .
>>
>> . . .
> 
> In my -r339076 build context I reverted -r334498, did a
> buildkernel, installed it, and rebooted into -r339076.
> 
> The result booted just fine.
> 
> It does appear that, for head, -r334498 makes the difference
> for some reason.

Unfortunately I have to confirm your findings.
Andreas