Re: [PATCH 10/10] arm: imx: imx8m: Add basic PSCI provider implementation

Marek Vasut
2022-12-22T03:58:09Z

On 12/22/22 04:05, Adam Ford wrote:
> On Wed, Dec 21, 2022 at 6:47 PM Marek Vasut <marex@denx.de> wrote:
>>
>> Implement basic PSCI provider to let OS turn CPU cores off and on,
>> power off and restart the system and determine PSCI version. This
>> is sufficient to remove the need for the ATF BL31 blob altogether.
>>
>> To make use of this functionality, active the following Kconfig options:
>> # CONFIG_PSCI_RESET is not set
>> CONFIG_ARMV8_MULTIENTRY=y
>> CONFIG_ARMV8_SET_SMPEN=y
>> CONFIG_ARMV8_SPL_EXCEPTION_VECTORS=y
>> CONFIG_ARMV8_EA_EL3_FIRST=y
>> CONFIG_ARMV8_PSCI=y
>> CONFIG_ARMV8_PSCI_CPUS_PER_CLUSTER=4
>> CONFIG_ARMV8_SECURE_BASE=0x970000
>
> I am guessing 0x970000 was for the 8MP based on the previous location
> of ATF. Is that true? If that's the case, can I assume that this
> address would be 0x910000, 0x920000 and 0x960000 for the imx8mq,
> imx8mm and imx8mn respectively?

It was for MX8MP, but you can pick whichever address you want, since it
is U-Boot that installs the SMC handlers, you are no longer forced to
somehow try and accommodate custom not well fitting load address picked
by some 3rd party binary blob.