[U-Boot] ARM: PSCI 0.1 vs 0.2

[Jan Kiszka <jan.kiszka@siemens.com>]

On 2014-11-10 14:08, Marc Zyngier wrote:
> On 10/11/14 12:51, Jan Kiszka wrote:
>> Hi Marc,
>>
>> what is the motivation to expose a PSCI 0.1 interface in U-boot, instead
>> of 0.2? Support for preexisting users of 0.1? The kernel seems to be
>> happy with both, and I'm now wondering if we should actually add the
>> legacy version to Jailhouse as well (I hope we can avoid this).
> 
> The initial rational was simple: at the time this code was written, the
> 0.2 spec still in review, and nobody was implementing it. Supporting 0.1
> was the only viable use-case.
> 
>> Still studying the logic: Is it possible to provide both interfaces, and
>> would it make sense?
> 
> Supporting both is very easy. Just output the 0.2 function numbers that
> actually make sense for 0.1 and have both compatible strings.

Ah, cool - parameters and return values of, say, CPU_ON/OFF are
compatible across both versions?

Jan

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