Re: [Qemu-devel] [PULL] qemu-sparc update

[Mark Cave-Ayland]

On 08/03/15 20:48, Alexander Graf wrote:

> On 08.03.15 06:57, Mark Cave-Ayland wrote:
>> On 08/03/15 10:31, Peter Maydell wrote:
>>
>>> On 8 March 2015 at 19:04, Mark Cave-Ayland
>>> <address@hidden> wrote:
>>>> On 08/03/15 09:47, Peter Maydell wrote:
>>>>
>>>>> On 4 March 2015 at 15:20, Mark Cave-Ayland
>>>>> <address@hidden> wrote:
>>>>>> Hi Peter,
>>>>>>
>>>>>> Here are the updates from my qemu-sparc tree. Please pull.
>>>>>
>>>>>>  MAINTAINERS               |    3 +
>>>>>>  hw/ppc/ppc.c              |  161 --------------------
>>>>>>  hw/ppc/ppc405_boards.c    |    2 +-
>>>>>>  hw/ppc/prep.c             |  163 ++++++++++++++++++--
>>>>>>  hw/sparc/sun4m.c          |   10 +-
>>>>>>  hw/sparc64/sun4u.c        |   20 ++-
>>>>>>  hw/timer/m48t59.c         |  359 
>>>>>> ++++++++++++++++++++++++++++++++-------------
>>>>>>  include/hw/timer/m48t59.h |   61 ++++----
>>>>>>  pc-bios/openbios-sparc64  |  Bin 1616768 -> 1616768 bytes
>>>>>>  qemu-doc.texi             |    7 +-
>>>>>
>>>>> Shouldn't there be an update to roms/openbios to go with the
>>>>> pc-bios/openbios-sparc64 binary blob update?
>>>>
>>>> I haven't committed the sun4u MMIO patches to OpenBIOS yet because
>>>> without the corresponding QEMU parts OpenBIOS SVN trunk breaks (and the
>>>> QEMU parts have taken many weeks to get right which is a long time to
>>>> leave things broken). Hence I've gone for just updating the binary which
>>>> is SVN trunk plus the NVRAM MMIO accessor changes in order to preserve
>>>> bisection.
>>>>
>>>> As soon as this is applied, I can apply my remaining OpenBIOS patches
>>>> and then send a separate qemu-openbios pull request which will bring
>>>> everything up to date.
>>>
>>> Hmm. I'm not a huge fan of having the binary in git and the submodule
>>> reference be out of step...
>>
>> Alternatively if you have shell access to git.qemu.org then I can commit
>> just the MMIO accessor changes to SVN trunk now and then with a manual
>> update to the OpenBIOS git mirror I can re-send the signed pull request
>> with updated binaries? I've deliberately held off applying patches to
>> OpenBIOS SVN trunk in case this was the preferred method as I'm keen to
>> be able to bisect down to this particular change on SPARC64.
> 
> Is there any way to make the change backwards compatible, so that we
> don't need to sync versions?

Not without refactoring to enable more than one type of NVRAM accessor
in OpenBIOS, plus a fw_cfg variable to enable the switch between the two
for SPARC64.

Given that SPARC64 is still more experimental than stable plus newer
versions of OpenBIOS aren't guaranteed to work with older versions of
QEMU anyhow, I just can't see that this is worth all the extra effort
for the sake of a follow-up pull request within a day or so that will
bring everything up to date whilst still allowing a proper bisection.

Now if Peter is still keen to keep the git submodule reference intact
then I'm happy to commit just the MMIO accessor changes to OpenBIOS SVN
trunk as long as we can minimise the time between the QEMU changes and
the OpenBIOS changes.


ATB,

Mark.