[PATCH 0/3] stm32mp: Attempt to resolve unintended breakage with v2021.10-rc2

[Patrick DELAUNAY]

On 10/8/21 1:28 PM, Marek Vasut wrote:
> On 10/8/21 11:18 AM, Patrick DELAUNAY wrote:
>> Hi Alex,
>
> Hi,
>
> [...]
>
>>> Without loss of generality, any CONFIG that conflates u-boot options 
>>> with SPL options is likely to cause some changes down the line.
>>>
>> I have a issue today with the generic part of ARM support:
>>
>> 1/ the PSCI is mandatory for Linux kernel
>
> PSCI is mandatory only on ARMv8 , NOT on ARMv7.
> And the "mandatory" part is forced onto everyone not by Linux kernel, 
> but by the architecture specification.
>
> [...]


Sorry for the short-cut... it is not really manadatory.


Today PSCI is required by the upstreamed Linux kernel on STM32MP15x 
Family to wake-up the secondary core and some other features (system 
reset / power-off).


STMicroelectronics decided to use the Power State Coordination Interface 
(PSCI) on all the STM32MP SoC (armv7 or armv8) even if PSCI it is only 
required in AArch64 for Embedded Base Boot Requirements (EBBR) Specification


https://arm-software.github.io/ebbr/index.html#document-chapter3-secureworld


Patrick