You can't run riscos on a m4, I am running on a53 core1. I will reply better later today.
Den fre 5 mars 2021 12:08Stefan Kalkowski <[email protected]> skrev: > Hello Michael, > > On Wed, Mar 03, 2021 at 11:22:33PM +0100, Michael Grunditz wrote: > > Hi, > > > > I have a kernel call that starts RISC OS, and uses psci. I wonder , > where > > should I put that very aarch64 dependent code. I somehow need to be able > > to call it from userspace. > > > > Regarding kernel calls in general , what is the best way of calling > them? > > Right now I do "MOV x0,#number ; SVC" , probably not very Genode style! > :) > > Actually, there is already support for what you are looking for, I > think. As far as I understood it correctly, you want to wake up the > Cortex-M4 (side-) processor, after you've prepared RiscOS to run on top of > it? > > Of course, you should not just add a system call that can be executed > by every component to do something like this ;-). But we already had > similar needs, when doing power control inside of the platform driver > for i.MX 8M. There are some GPC controls that are done by the ARM > Trusted firmware. Therefore we extended a previously existent > privilege to the so called "managing_system" privilege that can be > given when creating a new PD resp. component. This privilege is > typically given only to the platform driver. With it a component can > do a "managing_system(State&)" call on its PD session. This call transfers > registers (State == Cpu_state) to core, which on will do a "secure > monitor call" with the given registers (at least on ARMv8). > For further understanding, please grep for "managing_system" inside > base and base-hw. > > To sum it up, you could define a specific "Power_domain" for the M4 in > the platform driver of your board, and then do the corresponding SMC > call therein using the managing_system call. Your application doing > the RiscOS loading just needs to acquire the device with the M4 > Power_domain from the platform driver at the point where you want to > power it, and release it again when you want to power it off. > > This way, you will have a secure and sane integration of the M4 > handling. > > I hope I could somehow express myself comprehensivly. > > Best regards > Stefan > > > > > > > > > > > -- > > Michael Grunditz > > Sent from my RISC OS workstation.. > > > > _______________________________________________ > > Genode users mailing list > > [email protected] > > https://lists.genode.org/listinfo/users > > -- > Stefan Kalkowski > Genode labs > > https://github.com/skalk | https://genode.org > > _______________________________________________ > Genode users mailing list > [email protected] > https://lists.genode.org/listinfo/users
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