question about ARM11MP cpu architecture identification

[saeed bishara]

On Tue, Jan 12, 2010 at 6:55 PM, Catalin Marinas
<catalin.marinas at arm.com> wrote:
> On Tue, 2010-01-12 at 16:42 +0000, Russell King - ARM Linux wrote:
>> On Tue, Jan 12, 2010 at 04:26:12PM +0000, Catalin Marinas wrote:
>> > On Tue, 2010-01-12 at 16:21 +0000, saeed bishara wrote:
>> > >     The ARM11MP (rev r2p0) cpu architecture is ARMv6, and according to
>> > > the http://infocenter.arm.com, its Main ID register is 0x410FB024, and
>> > > the MMFR[3:0] is 3. but it looks to me that the cpu_architecture()
>> > > will identify it as ARMv7, and if the kernel was configured with
>> > > CPU_V7 only, then the lookup_processor_type() function also will
>> > > identify it as ARMv7. Am I missing something here?
>> >
>> > cpu_architecture() returns the architecture version of the supported MMU
>> > which on ARM11MPCore is the same as on ARMv7.
>> >
>> > Even if it is possible to configure both v6 and v7 in the same kernel, I
>> > don't think it is currently possible to successfully run such kernel.
>>
>> What makes you think that?  I've been building v6+v7 kernels for Realview
>> (with a patch to provide the right build options for the ARMv7 arch/arm/mm
>> files) and ISTR it works fine on my Realview board.
>
> I don't remember exactly but it didn't work for me some time ago. I
> think it failed to build (though I could have worked around this with
> something like -march=all).
>
I think you need the attached patch from Lennert (it was planned to be
sent later by me)

saeed
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