Hello, On 11.03.21 15:02, Alexandre TORGUE wrote: > On 3/11/21 12:43 PM, Marek Vasut wrote: >> On 3/11/21 9:08 AM, Alexandre TORGUE wrote: >>> 1- Break the current ABI: as soon as those patches are merged, stm32mp157c-dk2.dtb will impose to use >>> A tf-a for scmi clocks. For people using u-boot spl, the will have to create their own "no-secure" devicetree. >> >> NAK, this breaks existing boards and existing setups, e.g. DK2 that does not use ATF. >> >>> 2-As you suggest, create a new "secure" dtb per boards (Not my wish for maintenance perspectives). >> >> I agree with Alex (G) that the "secure" option should be opt-in. >> That way existing setups remain working and no extra requirements are imposed on MP1 users. Esp. since as far as I understand this, the "secure" part isn't really about security, but rather about moving clock configuration from Linux to some firmware blob. >> >>> 3- Keep kernel device tree as they are and applied this secure layer (scmi clocks phandle) thanks to dtbo in >>> U-boot. >> >> Is this really better than >> #include "stm32mp15xx-enable-secure-stuff.dtsi" >> in a board DT ? Because that is how I imagine the opt-in "secure" option could work. >> > > Discussing with Patrick about u-boot, we could use dtbo application thanks to extlinux.conf. BUT it it will not prevent other case (i.e. TF-A which jump directly in kernel@). So the "least worst" solution is to create a new "stm32mp1257c-scmi-dk2 board which will overload clock entries with a scmi phandle (as proposed by Alex). I raised this issue before with your colleagues. I still believe the correct way would be for the TF-A to pass down either a device tree or an overlay with the actual settings in use, e.g.: - Clocks/Resets done via SCMI - Reserved memory regions If TF-A directly boots Linux, it can apply the overlay itself, otherwise it's passed down to SSBL that applies it before booting Linux. Cheers, Ahmad > > Gabriel, can you wait a bit before sending something about SCMI in dtsi, I would like to align this strategy internally. > > Marek, Alex: thanks for your inputs. > > Regards > Alex > >>> The third could be the less costly. >> >> [...] > _______________________________________________ > Linux-stm32 mailing list > Linux-stm32@xxxxxxxxxxxxxxxxxxxxxxxxxxxx > https://st-md-mailman.stormreply.com/mailman/listinfo/linux-stm32 -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
