Re: [Qemu-devel] [PATCH 0/2] ACPI/arm-virt: add DBG2

[Al Stone]

On 09/08/2015 11:52 PM, Andrew Jones wrote:
> On Wed, Sep 09, 2015 at 12:25:45PM +0800, Shannon Zhao wrote:
>>
>>
>> On 2015/9/8 21:04, Leif Lindholm wrote:
>>> On Tue, Sep 08, 2015 at 11:18:27AM +0800, Shannon Zhao wrote:
>>>> On 2015/9/7 22:23, Leif Lindholm wrote:
>>>>> The Debug Port Table 2 (DBG2) is mandated by the ARM Server Base Boot
>>>>> Requirements specification. Add the DBG2 table definitions, and set up
>>>>> an entry in the ARM virt machine for the pl011 UART.
>>>>
>>>> Looking at Documentation/arm64/acpi_object_usage.txt in Linux kernel, it
>>>> says
>>>> "
>>>> DBG2   Signature Reserved (signature == "DBG2")
>>>>        == DeBuG port table 2 ==
>>>>        Microsoft only table, will not be supported.
>>>> "
>>>> It seems that Linux kernel doesn't support or need it, but Windows
>>>> requires it. So does it need to test this on Windows?
>>>
>>> No, it can be tested under Linux with the set I just sent out:
>>> http://lists.infradead.org/pipermail/linux-arm-kernel/2015-September/368614.html
>>
>> So you need to change Documentation/arm64/acpi_object_usage.txt as well.
>> But that is kernel side.
> 
> I also wonder if Documentation/arm64/arm-acpi.txt should have its
> "Booting using ACPI tables" section updated to reference (describe even?)
> the use of SPCR. Maybe Leif's already doing that with the
> this-time-really-for-upstream kernel spcr patches.
> 
> drew
> 

It's on my TODO list to update this documentation properly, to
include updates on DBG2 and SPCR along with a bunch of other
ACPI 6.0 changes.  My bad for the delays on this...

-- 
ciao,
al
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Al Stone
Software Engineer
Linaro Enterprise Group
address@hidden
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