From: wmb@firmworks.com (Mitch Bradley)
To: linux-arm-kernel@lists.infradead.org
Subject: RFC: ARM Boot standard for passing device tree blob
Date: Fri, 26 Mar 2010 07:43:20 -1000 [thread overview]
Message-ID: <4BACF238.3040405@firmworks.com> (raw)
In-Reply-To: <1269610665.807.51.camel@e102109-lin.cambridge.arm.com>
Catalin Marinas wrote:
> On Thu, 2010-03-25 at 21:04 +0000, Russell King - ARM Linux wrote:
>
>> On Wed, Mar 24, 2010 at 09:11:56AM -0600, Grant Likely wrote:
>>
>>> ===Required System State===
>>>
> [...]
>
>>> *IRQs disabled
>>> *MMU off
>>> *Instruction cache either on or off
>>> *Data cache turned off
>>>
>> Would recommend saying "Data cache(s) turned off" so that L2 cache is
>> included.
>>
>
> There are platforms where the L2 cache is turned on by the boot monitor
> (secure monitor) and Linux has no control over it (I think OMAP).
>
What is the reason for turning off the data caches? Leaving all caches
turned on and coherent with one another has always worked well for me at
the interface from firmware to a booted program.
WARNING: multiple messages have this Message-ID (diff)
From: Mitch Bradley <wmb-D5eQfiDGL7eakBO8gow8eQ@public.gmane.org>
To: Catalin Marinas <catalin.marinas-5wv7dgnIgG8@public.gmane.org>
Cc: Russell King - ARM Linux
<linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
devicetree-discuss
<devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org>,
Philippe Robin <Philippe.Robin-5wv7dgnIgG8@public.gmane.org>,
David Rusling <David.Rusling-5wv7dgnIgG8@public.gmane.org>,
Jeremy Kerr <jeremy.kerr-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org>,
Dave P Martin <Dave.Martin-5wv7dgnIgG8@public.gmane.org>,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: RFC: ARM Boot standard for passing device tree blob
Date: Fri, 26 Mar 2010 07:43:20 -1000 [thread overview]
Message-ID: <4BACF238.3040405@firmworks.com> (raw)
In-Reply-To: <1269610665.807.51.camel-uqmqopRKlSLZROr8t4l/smS4ubULX0JqMm0uRHvK7Nw@public.gmane.org>
Catalin Marinas wrote:
> On Thu, 2010-03-25 at 21:04 +0000, Russell King - ARM Linux wrote:
>
>> On Wed, Mar 24, 2010 at 09:11:56AM -0600, Grant Likely wrote:
>>
>>> ===Required System State===
>>>
> [...]
>
>>> *IRQs disabled
>>> *MMU off
>>> *Instruction cache either on or off
>>> *Data cache turned off
>>>
>> Would recommend saying "Data cache(s) turned off" so that L2 cache is
>> included.
>>
>
> There are platforms where the L2 cache is turned on by the boot monitor
> (secure monitor) and Linux has no control over it (I think OMAP).
>
What is the reason for turning off the data caches? Leaving all caches
turned on and coherent with one another has always worked well for me at
the interface from firmware to a booted program.
next prev parent reply other threads:[~2010-03-26 17:43 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-24 15:11 RFC: ARM Boot standard for passing device tree blob Grant Likely
2010-03-24 15:11 ` Grant Likely
2010-03-25 21:04 ` Russell King - ARM Linux
2010-03-25 21:04 ` Russell King - ARM Linux
2010-03-25 23:40 ` David Gibson
2010-03-25 23:40 ` David Gibson
2010-03-26 0:23 ` Jeremy Kerr
2010-03-26 0:23 ` Jeremy Kerr
2010-03-26 3:24 ` Grant Likely
2010-03-26 3:24 ` Grant Likely
2010-03-26 13:37 ` Catalin Marinas
2010-03-26 13:37 ` Catalin Marinas
2010-03-26 17:43 ` Mitch Bradley [this message]
2010-03-26 17:43 ` Mitch Bradley
2010-03-26 18:13 ` Grant Likely
2010-03-26 18:13 ` Grant Likely
2010-03-26 19:30 ` Nicolas Pitre
2010-03-26 19:30 ` Nicolas Pitre
2010-03-26 19:52 ` Grant Likely
2010-03-26 19:52 ` Grant Likely
2010-03-26 23:03 ` Russell King - ARM Linux
2010-03-26 23:03 ` Russell King - ARM Linux
2010-03-29 11:24 ` Dave P. Martin
2010-03-29 11:24 ` Dave P. Martin
2010-03-30 0:26 ` Jamie Lokier
2010-03-30 0:26 ` Jamie Lokier
2010-03-30 13:32 ` Dave P. Martin
2010-03-30 13:32 ` Dave P. Martin
2010-03-26 23:00 ` Russell King - ARM Linux
2010-03-26 23:00 ` Russell King - ARM Linux
2010-03-31 1:10 ` Ben Dooks
2010-03-31 1:10 ` Ben Dooks
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