On 1/7/25 1:11 PM, Peng Fan wrote:
[...]
You cannot replace System Manager with optee-os.
I think optee-os is also capable of being SCMI provider, so I have to wonder, why does NXP use custom hand-written SCMI provider instead of something already available, like that optee-os ?
System controller is the central controller of the system, and i.MX95 needs support safety.
We need to make sure when A55 crashes, safety core still work properly.
I think we are conflating two separate functionalities here:
- SM as the always-running monitor software - SM as the SCMI provider
... please read on ...
And one more question, would it be possible to make U-Boot NOT depend on SCMI at all and instead have regular clock/pinctrl drivers which can configure the hardware using plain register writes, like it is done on MX8M and older SoCs ?
See https://www.nxp.com/docs/en/data-sheet/IMX95CEC.pdf Only one boot mode: Low Power Boot (LPB): only M33 core is running after POR
OK
You may configure TRDC to assign resources to A55, but you still need to make sure M33 work proper.
... so, I wonder, can the M33 act as SM, and can U-Boot configure whatever it needs via plain register writes, without having to rely on SCMI ?