Date: Fri, 26 Jun 2009 17:00:51 +0200
From: Ingo Molnar <mingo@elte.hu>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Pan, Jacob jun" <jacob.jun.pan@intel.com>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       "H. Peter Anvin" <hpa@linux.intel.com>,
       Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 3/9] x86/moorestown: add moorestown platform flags
Message-ID: <20090626150051.GA22223@elte.hu>
References: <43F901BD926A4E43B106BF17856F07556412B7E2@orsmsx508.amr.corp.intel.com> <20090626071955.GG14078@elte.hu> <20090626101310.4110a290@lxorguk.ukuu.org.uk> <20090626093859.GA12571@elte.hu> <20090626111603.758ec7fb@lxorguk.ukuu.org.uk> <20090626110429.GB12446@elte.hu>
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* Ingo Molnar <mingo@elte.hu> wrote:

> And? There's an obvious quality difference between various 
> platform enumeration methods - and we strive for the highest 
> quality methods.
> 
> Using boot flags is one of the lowest quality enumeration methods 
> and the fact that there's precedence for it in other architectures 
> is not a technical reason to make the same mistakes on x86 too.
> 
> Especially here where there's two other enumeration methods easily 
> available: SFI and PCI. Any of those suffices.

btw., the "I am MRST" bootstrap info is certainly doable via a 
bootloader flag as well, if this platform is _so_ deprived of basic 
PC features that it has no other channel of information. Especially 
if it has no BIOS and if the bootloader provides the memory map as 
well - which seems to be the case here.

I can understand the PCI ID space being potentially awkward (if many 
models with mismatching PCI IDs are planned) - so it's certainly 
possible that the only thing that remains in the end is the 
bootloader provided flag - no matter how sucky that may be.

So i am not trying to make a bigger deal out of this than it really 
deserves and this is not a showstopper in my eyes - but this is 
really an exceptional case and shouldnt be the glory model for how 
ultra embedded should be done on x86 ...

	Ingo
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