head -r365932 on PowerMac G5 (2 dual-core sockets): Crashes before login prompt if powerd is enabled in /etc/rc.conf

[Mark Millard]

On 2020-Sep-23, at 09:09, Brandon Bergren <bdragon at FreeBSD.org> wrote:

> On Wed, Sep 23, 2020, at 3:58 AM, Mark Millard wrote:
>> On 2020-Sep-23, at 00:04, Brandon Bergren <bdragon at FreeBSD.org> wrote:
>> 
>>> On Tue, Sep 22, 2020, at 7:50 PM, Mark Millard wrote:
>>>> 
>>>> 
>>>> On 2020-Sep-22, at 17:18, Mark Millard <marklmi at yahoo.com> wrote:
>>>>> By "immediately" I mean I do not even get close to
>>>>> seeing the loader prompt. The display still shows
>>>>> OpenFirmware content: it has not been cleared yet.
>>>>> 
>>>> 
>>>> Just to be explicit: the dual socket G4 is the only type
>>>> of G3/G4 that does make it to the loader prompt (and a
>>>> little beyond). The G5 2 dual-core sockets is the only
>>>> context that I've tried that gets very far past the
>>>> loader prompt.
>>> 
>>> This is strange. Loader works just fine on all of my G4 equipment.
>>> 
>>> Are you making sure to use the "dev /memory at 0 100000 1000 do-unmap" trick on 4.8.7f1 devices?
>> 
>> I know nothing about that and have never had to do such a thing
>> historically. I've never had to identify "4.8.7f1 devices".
> 
> There is a bug in some versions of the PowerMac BootROM where a memory page at 0x100000 would remain mapped without being properly listed in the mmu properties (likely due to the way Open Firmware was initialized) that breaks bootloaders that touch that page.
> 
> It is known to be a thing on at least 4.8.7f1 BootROM, but may also affect other versions. You can see the BootROM version on the OpenFirmware screen when the machine turns on.
> 
> On affected devices, the bug can be permanently repaired using nvedit to execute the workaround automatically, or it can be typed in by hand every time.
> 
> This is described on https://wiki.freebsd.org/powerpc

I've been doing things this way with the SSDs since sometime
in 2014 on the same machines since then. I've never run into
the problem prior to now.

>>> How are you starting loader?
>> 
>> Turn the PowerMac on with the SSD already plugged onto the
>> IDE adapter that I have in place. (The G3 is configured
>> such that I also have to type mac-boot to OpenFirmware.)
>> 
>> It is the same SSD being moved between the 2 dual-core socket G5,
>> 2 socket G4, 1 socket G4, and the G3. So it is significant that
>> the 2 socket G4/G5 do get to the loader prompt but the others
>> do not.
>> 
>> 1-socket G4/G3 example lines:
>> 
>> QUOTE
>> ofw_close: devh=0x0
>> 
>>>> FreeBSD/powerpc Open Firmware boot block
>>   Boot path:   /pci at f2000000/mac-io at 17/ata-4 at 1f000/@0:
>>   Boot loader: /boot/loader
>>   Boot volume:   /pci at f2000000/mac-io at 17/ata-4 at 1f000/@0:3
>> END QUOTE
> 
> How was this SSD set up?

The build is my own (cross build). For the kernel I install
on the host to a directory, tar that to a PowerMac, and
later expand the tar to the SSD in question. Like I've been
doing since 2014 on the same set of PowerMacs. (The procedure
avoids the little-endian host vs. big-endian UFS on the
PowerMacs.)

> When was the last time you reinstalled boot1.hfs?

It been a while but this setup was working before the
update to head -r365932 . When was the last time
boot1.hfs had a required change? Recently?

The same boot1.hfs on the same SSD gets to the
loader prompt on any 2 socket PowerMac that I
try. (I do not have access to a 1 socket 2-core
PowerMac.) And, again, this same boot1.hfs on the
same SSD worked before the update to head -r365932 .

> You aren't trying to use memstick.img, correct? That's known to be be broken currently.

I'm doing my own builds, the same as I did with
the version installed and in use before I updated
to head -r365932 . I've been doing my own builds
since 2014.

>> 
>> No more shows up for the 1 socket PowerMacs.
>> 
>>> Is this on cdrom, network, or usb?
>> 
>> SSD hanging off the IDE bus via an adapter.
>> 
>>> To confirm, it doesn't get as far as the kernel loading spinner?
>> 
>> It does not. See above.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)