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

Marek Vasut marex at denx.de
Tue Jan 3 00:41:38 CET 2023

On 1/2/23 17:44, Adam Ford wrote:
> On Wed, Dec 21, 2022 at 9:58 PM Marek Vasut <marex at denx.de> wrote:
>> On 12/22/22 04:05, Adam Ford wrote:
>>> On Wed, Dec 21, 2022 at 6:47 PM Marek Vasut <marex at 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_PSCI=y
>>>>     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.
> I patched U-Boot's master with this series and I tried it on
> imx8mn_beacon and imx8mm_beacon without success. I never even saw the
> SPL message.  I tried to focus on the Nano since the boot ROM in that
> one is more similar to that of the 8mp, but the behaviour was similar
> to that of the Nano.  Are there any dependencies or should I have used
> a specific starting branch?

Nope . But if you don't even see output from SPL, that's where I would 
start looking. Do you see output from SPL without this series ? Note 
that bulk of this series content applies to U-Boot proper, not SPL so far.

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