On Tue, Jan 07, 2025 at 01:37:06PM +0100, Marek Vasut wrote: >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 ?
Technically yes for prototype building, except TRDC and other secure periphrals. Regards, Peng
