Re: [PATCH] arm/docs: Clarify legacy DT bindings on UEFI

[Luca Fancellu <luca.fancellu@xxxxxxx>]

> On 13 Oct 2021, at 15:30, Julien Grall <julien@xxxxxxx> wrote:
> 
> Hi Luca,
> 
> On 13/10/2021 15:06, Luca Fancellu wrote:
>>> On 13 Oct 2021, at 14:27, Julien Grall <julien@xxxxxxx> wrote:
>>> 
>>> Hi Luca,
>>> 
>>> On 13/10/2021 13:19, Luca Fancellu wrote:
>>>> Legacy compatible strings for dom0 modules are not
>>>> supported when booting using UEFI, the documentation
>>>> doesn't mention that.
>>> 
>>> Can you add a summary in the commit message why we consider the legacy 
>>> binding is not supported?
>> Yes what about:
>> Since the introduction of UEFI boot for Xen, the legacy
>> compatible strings were not supported and the stub code
>> was checking only the presence of “multiboot,module” to
>> require the Xen UEFI configuration file or not.
>> The documentation was not updated to specify that behavior.
>> Add a phrase to docs/misc/arm/device-tree/booting.txt
>> to clarify it.
> 
> Sounds good to me. You can add my ack on it:
> 
> Acked-by: Julien Grall <jgrall@xxxxxxxxxx>
> 
> Would you be able to respin the patch with the two changes?

Yes I will, thank you.

Cheers,
Luca

> 
>>> 
>>>> Add a phrase to docs/misc/arm/device-tree/booting.txt
>>>> to clarify it.
>>>> Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
>>>> ---
>>>>  docs/misc/arm/device-tree/booting.txt | 2 ++
>>>>  1 file changed, 2 insertions(+)
>>>> diff --git a/docs/misc/arm/device-tree/booting.txt 
>>>> b/docs/misc/arm/device-tree/booting.txt
>>>> index c6a775f4e8..017c0f13eb 100644
>>>> --- a/docs/misc/arm/device-tree/booting.txt
>>>> +++ b/docs/misc/arm/device-tree/booting.txt
>>>> @@ -51,6 +51,8 @@ Each node contains the following properties:
>>>>    Xen 4.4 supported a different set of legacy compatible strings
>>>>    which remain supported such that systems supporting both 4.4
>>>>    and later can use a single DTB.
>>>> +  However when booting Xen using UEFI and Device Tree, the legacy
>>> 
>>> NIT: I would drop "and Device Tree" because this feels a bit redundant as 
>>> this compatible can only be used in the Device-Tree.
>> I will drop it
>>> 
>>>> +  compatible strings are not supported.
>>>>            - "xen,multiboot-module" equivalent to "multiboot,module"
>>>>    - "xen,linux-zimage"     equivalent to "multiboot,kernel"
>>> 
>>> Cheers,
>>> 
>>> -- 
>>> Julien Grall
> 
> Cheers,
> 
> -- 
> Julien Grall