Re: [GIT PULL] omap changes for v2.6.39 merge window

From: Koen Kooi
Date: Thu Mar 31 2011 - 14:09:06 EST



Op 31 mrt 2011, om 19:22 heeft david@xxxxxxx het volgende geschreven:

> On Thu, 31 Mar 2011, Russell King - ARM Linux wrote:
>
>> On Thu, Mar 31, 2011 at 10:54:40AM +0100, Alan Cox wrote:
>>> If I boot it on a current PC I'm booting on a multiprocessor system with
>>> different timers, totally different IRQ controllers, different keyboard
>>> controllers (USB), PCI Express, an IOMMU, NCQ SATA, ACPI, graphics
>>> running in shared host memory able to give/take pages from the host,
>>> extra instructions, etc etc
>>>
>>> And the same kernel boots just fine on both just fine.
>>
>> We've been there for a long time with ARM. Right from the start I had
>> a single kernel image which booted over a range of ARM CPUs and
>> platforms.
>>
>> As far as ARM CPU architectures go, today we can have a single kernel
>> image which covers ARMv3 to ARMv5, and a separate kernel image which
>> covers ARMv6 to ARMv7 including SMP and UP variants. The thing which
>> currently stops ARMv3 to ARMv7 all together is the different page table
>> layouts, the ASID tagging, the exclusive load/store support for cmpxchg
>> and other atomic operations, etc.
>
> I don't think the push is to get a single kernel image that boots absolutly everywhere. having separate ARM5 and ARM7 kernels doesn't seem to be a big deal to anyone.

You mean ARMv5 and ARMv7, right? ARM5 and ARM7 are completely different things.

The short, but inaccurate version:

ARM9 -> ARMv4t, ARMv5te*
ARM11 -> ARMv6*
CORTEX-A* -> ARMv7a

regards,

Koen--
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