I think I found why the iMac G3 that I have access to has not booted FreeBSD vintages: 2015-Mar+ . . . [Yep: booted!]

[Mark Millard]

On 2016-Nov-25, at 2:12 PM, Mark Millard <markmi at dsl-only.net> wrote:

> On 2016-Nov-25, at 11:37 AM, Justin Hibbits <chmeeedalf at gmail.com> wrote:
> 
>> Hi Mark,
>> 
>> Nice legwork on this. I just committed r309167 which should fix this bug. Can you update and test?
>> 
>> - Justin

Works fine in my testing.

I took my head -r308874 environments for powerpc and powerpc64
and . . .

A) Used: "svnlite revert" on my change for the issue.
B) Used: "svnlite update -r309167 /usr/src/sys/powerpc/include/cpufunc.h"
C) Rebuilt kernels for TARGET_ARCH=powerpc and TARGET_ARCH=powerpc64
D) Installed them.
E) Used "objdump -d" to confirm the mtsrin-then-isync sequences
   in the kernels.
F) For TARGET_ARCH=powerpc:
F.1) Booted the iMac G3
F.2) Booted a couple of PowerMac G4s
F.3) Booted a couple of PowerMac G5s
G) For TARGET_ARCH=powerpc64:
G.1) Booted a couple of PowerMac G5s

All worked fine with your code update.

This sequence avoided getting the clang 3.9.0 update involved,
separating the testing concerns.



[I avoided one PowerMac G4 that no version of FreeBSD that I've
tried in it has ever managed to finish booting: the attempts
hang when normally the next normal message would be the first
about finding the usb keyboard. Same boot SSD and keyboard work
everyplace else each time that I've tried, various keyboards
tried. Mac OS X and Ubuntu variants that I've tried boot and
operate the odd PowerMac just fine. I've never made any
progress on figuring this issue out.]

===
Mark Millard
markmi at dsl-only.net