Re: [RFC PATCH qemu] spapr/docs: Add a few words about x-vof

[Daniel Henrique Barboza <danielhb413@gmail.com>]

On 5/13/22 04:45, Alexey Kardashevskiy wrote:
> 
> 
> On 5/12/22 23:40, Daniel Henrique Barboza wrote:
>>
>>
>> On 5/12/22 00:10, Alexey Kardashevskiy wrote:
>>>
>>>
>>> On 5/12/22 06:42, Daniel Henrique Barboza wrote:
>>>>
>>>>
>>>> On 5/6/22 02:51, Alexey Kardashevskiy wrote:
>>>>> The alternative small firmware needs a few words of what it can and
>>>>> absolutely cannot do; this adds those words.
>>>>>
>>>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>>>> ---
>>>>>   docs/system/ppc/pseries.rst | 28 ++++++++++++++++++++++++++++
>>>>>   1 file changed, 28 insertions(+)
>>>>>
>>>>> diff --git a/docs/system/ppc/pseries.rst b/docs/system/ppc/pseries.rst
>>>>> index d9b65ad4e850..4c98a94f9add 100644
>>>>> --- a/docs/system/ppc/pseries.rst
>>>>> +++ b/docs/system/ppc/pseries.rst
>>>>> @@ -32,14 +32,42 @@ Missing devices
>>>>>   Firmware
>>>>>   ========
>>>>> +The pSeries platform in QEMU comes with 2 firmwares:
>>>>> +
>>>>>   `SLOF <https://github.com/aik/SLOF>`_ (Slimline Open Firmware) is an
>>>>>   implementation of the `IEEE 1275-1994, Standard for Boot (Initialization
>>>>>   Configuration) Firmware: Core Requirements and Practices
>>>>>   <https://standards.ieee.org/standard/1275-1994.html>`_.
>>>>> +SLOF performs bus scanning, PCI resource allocation, provides the client
>>>>> +interface to boot from block devices and network.
>>>>> +
>>>>>   QEMU includes a prebuilt image of SLOF which is updated when a more recent
>>>>>   version is required.
>>>>> +VOF (Virtual Open Firmware) is a minimalistic firmware to work with
>>>>> +``-machine pseries,x-vof=on``. When enabled, the firmware acts as a slim
>>>>> +shim and QEMU implements parts of the IEEE 1275 Open Firmware interface.
>>>>> +
>>>>> +VOF does not have device drivers, does not do PCI resource allocation and
>>>>> +relies on ``-kernel`` used with Linux kernels recent enough (v5.4+)
>>>>> +to PCI resource assignment. It is ideal to use with petitboot.
>>>>> +
>>>>> +Booting via ``-kernel`` supports the following:
>>>>> ++-------------------+-------------------+------------------+
>>>>> +| kernel            | pseries,x-vof=off | pseries,x-vof=on |
>>>>> ++===================+===================+==================+
>>>>> +| vmlinux BE        |     ✓             |     ✓            |
>>>>> ++-------------------+-------------------+------------------+
>>>>> +| vmlinux LE        |     ✓             |     ✓            |
>>>>> ++-------------------+-------------------+------------------+
>>>>> +| zImage.pseries BE |     x             |     ✓¹           |
>>>>> ++-------------------+-------------------+------------------+
>>>>> +| zImage.pseries LE |     ✓             |     ✓            |
>>>>> ++-------------------+-------------------+------------------+
>>>>
>>>> You need an empty line at the start and at the end of the table. Otherwise it'll
>>>> be rendered as regular text.
>>>
>>> How do you build htmls from these btw?
>>
>> Had to do this yesterday because I changed machines recently. In a Fedora 35
>> system I did this:
>>
>>
>> sudo dnf install python3-sphinx
>> sudo dnf install python-sphinx_rtd_theme-doc
>> pip install sphinx_rtd_theme
> 
> 
> I only needed the last one, compiles htmls now. I was trying to figure out in Makefiles where is that "html" target and I just could not :)
> 
> 
>>
>> (not sure if all steps are needed)
>>
>> Then the generated docs will be under build/docs/manual .
>>
>>
>>>
>>>>
>>>>> +Notes:
>>>>
>>>> I also don't believe you need the "Notes:" addendum here. It's clear that you're
>>>> making an observation about the zImage.pseries BE and x-vof=on case.
>>>
>>> But only this combination needs kernel-addr=0, other images do not need that with SLOF or VOF.
>>
>>
>> I mentioned about the "Notes:" string. We can remove it and leave just the
>>
>> +¹ must set kernel-addr=0
>>
>>
>> Since it's clear that you're making a note about that item in the table.
>>
>>
>>
>>>
>>>
>>>>
>>>> Everything else LGTM. If no one else has any comment, and you're ok with these
>>>> changes I mentioned, I can amend it myself with my R-b.
>>>
>>> I'll probably repost after the other patch with kernel-addr is merged into your tree. Thanks,
>>
>> I already picked it (just waiting some tests to finish). But feel free to
>> send a v2 if you want to play around generating the docs to see how
>> your patch looks like in the finished HTML.
> 
> 
> Nah, the changes you made are fine so I am not planning on posting another version. Thanks for fixing it up.


No problem!


Queued in gitlab.com/danielhb/qemu/tree/ppc-next. Thanks,


Daniel

> 
> 
>>
>>
>> Thanks,
>>
>>
>> Daniel
>>
>>>
>>>
>>>>
>>>>
>>>>
>>>> Thanks,
>>>>
>>>>
>>>> Daniel
>>>>
>>>>
>>>>> +¹ must set kernel-addr=0
>>>>> +
>>>>>   Build directions
>>>>>   ================
>>>
>