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Date: Wed, 12 Nov 2014 10:55:45 +0000
From: Julien Grall <julien.grall@linaro.org>
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Subject: Re: [Qemu-devel] [Linaro-acpi] [RFC PATCH 0/7] hw/arm/virt: Dynamic
 ACPI v5.1 table generation
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To: Christoffer Dall <christoffer.dall@linaro.org>, Mark Rutland <mark.rutland@arm.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, "Ian.Campbell@citrix.com" <Ian.Campbell@citrix.com>, "linaro-acpi@lists.linaro.org" <linaro-acpi@lists.linaro.org>, Alexander Spyridakis <a.spyridakis@virtualopensystems.com>, Claudio Fontana <claudio.fontana@huawei.com>, QEMU Developers <qemu-devel@nongnu.org>, Leif Lindholm <leif.lindholm@linaro.org>, "stefano.stabellini@citrix.com" <stefano.stabellini@citrix.com>, Grant Likely <grant.likely@linaro.org>, "tech@virtualopensystems.com" <tech@virtualopensystems.com>, Parth Dixit <parth.dixit@linaro.org>

Hi,

On 12/11/2014 10:44, Christoffer Dall wrote:
>>
>> I'm not a fan of placing fundamentally required system description on
>> the command line. It's fine for explicit overrides but I don't think it
>> should be the default mechanism as that causes its own set of problems
>> (who wants to fight with their hypervisor to pass a command line to a
>> guest kernel?).
>>
>
> Agreed completely, but I've been lacking strong technical arguments
> against passing this stuff on the cmdline.  My personal preferred
> approach for the Xen Dom0 case is to add a property to the DT.

IHMO, the cmdline is OS specific, therefore this solution wouldn't fit 
to support ACPI on other OS (i.e *BSD) without requiring specific 
implementation/parsing of the command line.

The DT solution would be cleaner and the bindings are already 
standardize (and starting to be used on other OS such as FreeBSD).

Regards,

-- 
Julien Grall