From: slash.tmp@free•fr (Mason)
To: linux-arm-kernel@lists•infradead.org
Subject: Steps to submit a new arch/arm port
Date: Fri, 25 Sep 2015 17:28:54 +0200 [thread overview]
Message-ID: <56056836.4060307@free.fr> (raw)
In-Reply-To: <7559792.th4E1kM5gi@wuerfel>
On 25/09/2015 16:11, Arnd Bergmann wrote:
> On Friday 25 September 2015 15:35:36 Mason wrote:
>> On 25/09/2015 15:17, Arnd Bergmann wrote:
>>> On Friday 25 September 2015 15:06:32 Mason wrote:
>>>
>>>> I've trimmed my platform Kconfig down to:
>>>>
>>>> config ARCH_TANGO4
>>>> bool "Sigma Designs Tango4 (SMP87xx)"
>>>> default y
>>>
>>> drop the default
>>>
>>> add
>>> depends on CPU_MULTI_V7
>>
>> I've done this higher up.
>>
>> menuconfig ARCH_TANGOX
>> bool "Sigma Designs Tango" if ARCH_MULTI_V7
>> help
>> something useful
>>
>> if ARCH_TANGOX
>> config ARCH_TANGO4
>> ...
>> endif
>>
>> So 'default y' enables ARCH_TANGO4 only if ARCH_TANGOX is selected,
>> right?
>
> You should really only have one of the two.
I plan to add ARCH_TANGO5 in a few weeks. So I copied the layout used
by Samsung for EXYNOSx and TI for OMAPx.
>>>> select ARCH_HAS_HOLES_MEMORYMODEL
>>>> select ARM_ERRATA_754322
>>>> select ARM_ERRATA_764369
>>>
>>> add 'if SMP'
>>>
>>>> select ARM_GIC
>>>> select CACHE_L2X0
>>>
>>> remove CACHE_L2X0, we want to be able to turn this off.
>>
>> Some people run with L2 disabled? That's a strange thing to do.
>
> I can help for testing. Most importantly, we currently allow that
> configuration today, and it's not up to you to forbid other platforms
> from doing it.
As far as I can tell, I'm running with L2 disabled anyway, since
Linux is running in non-secure mode, and I didn't provide the ABI
to talk to the secure OS.
> If you can prove that we never need to disable that option, send
> another patch to make it unconditional.
CACHE_L2X0 defaults to y. That's good enough for me.
>>>> select CLKSRC_MMIO
>>>> select GENERIC_IRQ_CHIP
>>>> select HAVE_ARM_SCU
>>>> select HAVE_ARM_TWD
>>>
>>> 'if SMP'
>>>
>>>> select NEON
>>>> select SMP
>>>
>>> These should be user-selectable as well, so drop the 'select'
>>> and make sure the kernel builds with them turned off.
About NEON. I had 'select VFP' but I see that CPU_V7 enables VFPv3 and VFP.
Isn't NEON required to support user-space programs using NEON instructions?
arch/arm/kernel/entry-armv.S
>> It will build, but it won't run! My port uses the TWD for clockevents,
>> and smp_twd.c is only compiled if HAVE_ARM_TWD. So I must set SMP.
>
> I think this has come up before and should be fixed. Could you
> send a patch that allows using TWD in uniprocessor configurations?
This was discussed here:
http://thread.gmane.org/gmane.linux.ports.arm.kernel/389931/focus=15737
I can re-post the same patch.
Regards.
next prev parent reply other threads:[~2015-09-25 15:28 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-21 15:00 Steps to submit a new arch/arm port Mason
2015-09-21 15:49 ` Arnd Bergmann
2015-09-22 14:36 ` Mason
2015-09-22 14:51 ` Arnd Bergmann
2015-09-22 14:56 ` Russell King - ARM Linux
2015-09-22 15:54 ` Mason
2015-09-22 16:29 ` Russell King - ARM Linux
2015-09-23 8:49 ` Mason
2015-09-23 9:13 ` Russell King - ARM Linux
2015-09-23 9:21 ` Mason
2015-09-23 9:26 ` Russell King - ARM Linux
2015-09-22 19:15 ` Arnd Bergmann
2015-09-23 9:26 ` Mason
2015-09-23 9:34 ` Arnd Bergmann
2015-09-25 13:06 ` Mason
2015-09-25 13:17 ` Arnd Bergmann
2015-09-25 13:35 ` Mason
2015-09-25 14:11 ` Arnd Bergmann
2015-09-25 15:28 ` Mason [this message]
2015-09-25 15:33 ` Mason
2015-09-25 15:49 ` Arnd Bergmann
2015-09-25 15:52 ` Arnd Bergmann
2015-09-25 16:09 ` Mason
2015-09-25 17:20 ` Arnd Bergmann
2015-09-28 13:48 ` Mason
2015-09-28 14:43 ` Måns Rullgård
2015-09-28 16:32 ` Mason
2015-09-28 17:29 ` Russell King - ARM Linux
2015-09-22 15:48 ` Måns Rullgård
2015-09-25 9:27 ` Mason
2015-09-25 9:46 ` Javier Martinez Canillas
2015-09-25 11:56 ` Arnd Bergmann
2015-09-25 12:06 ` Russell King - ARM Linux
2015-09-21 15:51 ` Måns Rullgård
2015-09-21 16:13 ` Russell King - ARM Linux
2015-09-22 16:08 ` Mason
2015-09-22 16:24 ` Russell King - ARM Linux
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