From: vladimir.murzin@arm•com (Vladimir Murzin)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 0/4] arm/versatile: no-MMU support
Date: Wed, 7 Dec 2016 14:27:08 +0000 [thread overview]
Message-ID: <58481C3C.9090006@arm.com> (raw)
In-Reply-To: <22e20a24-5f1e-a23d-0d18-31dc14179cf5@westnet.com.au>
Hi Greg,
On 07/12/16 14:21, Greg Ungerer wrote:
> Hi Vladimir,
>
> On 07/12/16 23:57, Greg Ungerer wrote:
>> On 07/12/16 19:23, Vladimir Murzin wrote:
>>> On 07/12/16 06:08, Greg Ungerer wrote:
>>>> Does the ARM Versatile machine have a maintainer?
>>>> I have CC'ed this patch set to those names reported by get_maintainer.
>>>> I had no feedback on the first posting of this series back in August.
>>>>
>>>> The following patches support configuring and building the versatile
>>>> machine with a no-MMU kernel.
>>>>
>>>> There is only a few minor changes required. It was previously possible
>>>> in older kernels to build for versatile with CONFIG_MMU disabled, but
>>>> the change to devicetree lost that capability. These changes make it
>>>> possible again.
>>>>
>>>> One patch is a fix for address translation (broken in older kernels
>>>> too),
>>>> two are build problems when CONFIG_MMU is disabled, and the last is the
>>>> actuall configuration changes needed.
>>>>
>>>> The motivation for this is that the versatile machine is well supported
>>>> in qemu. And this provides an excellent platform for development and
>>>> testing no-MMU support on ARM in general. With these patches applied
>>>> it is possible to build and run a kernel with MMU disabled on qemu.
>>>
>>> I'm wondering if my "Allow NOMMU for MULTIPLATFORM" series [1] work
>>> for you?
>>>
>>> [1] https://www.spinics.net/lists/arm-kernel/msg546823.html
>>
>> Sorry I hadn't seen these patches before.
>>
>> Just tried them out. With CONFIG_EXPERT set I can select and
>> build for the Versatile machine with CONFIG_MMU not set. The
>> build is successful, but the resulting kernel doesn't boot.
>>
>> I see that the resulting .config has CONFIG_PLAT_VERSATILE set
>> but not CONFIG_ARCH_VERSATILE. Is this intentional?
>
> Let me revise that. By setting the "Multiple platform selection"
> selection correctly to v5 platforms I did get CONFIG_ARCH_VERSATILE
> set, and could still successfully build the kernel.
>
> A couple of other config options I had to readjust and I can
> boot up this kernel under qemu. So success!
>
Congrats!!!
Thanks for trying these patches! It is really nice to see someone else shows
interest on NOMMU! If you don't mind I'll keep you in Cc when/if I re-spin my
patches ;)
Cheers
Vladimir
>
>> With CONFIG_ARCH_VERSATILE missing the build doesn't traverse
>> into arch/arm/mach-versatile, and you don't get any device tree
>> built.
>>
>> Ultimately to produce a working kernel we will still need my
>> patch 01/04 ("ARM: versatile: support no-MMU mode addressing").
>> No surprise here, this was missing in older kernels too.
>
> So in the end this is the only extra change I needed as well
> to get the running kernel.
>
> Regards
> Greg
>
>
>
next prev parent reply other threads:[~2016-12-07 14:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-07 6:08 [PATCH 0/4] arm/versatile: no-MMU support Greg Ungerer
2016-12-07 6:08 ` [PATCH 1/4] ARM: versatile: support no-MMU mode addressing Greg Ungerer
2016-12-07 6:08 ` [PATCH 2/4] ARM: versatile: define empty debug_ll_io_init() for no-MMU Greg Ungerer
2016-12-07 9:23 ` [PATCH 0/4] arm/versatile: no-MMU support Vladimir Murzin
2016-12-07 13:57 ` Greg Ungerer
2016-12-07 14:13 ` Vladimir Murzin
2016-12-07 14:21 ` Greg Ungerer
2016-12-07 14:27 ` Vladimir Murzin [this message]
2016-12-07 14:40 ` Greg Ungerer
2016-12-07 14:16 ` Linus Walleij
-- strict thread matches above, loose matches on Subject: below --
2016-09-26 0:52 Greg Ungerer
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