This boils down to how the authority to perform SMC calls should be controlled. SMC calls have to be invoked at EL1 or EL2, so an EL0 VMM or app is unable to issue an SMC. Therefore, a new system call might be needed. Anyone has any thoughts on what existing or new Cap we should use for the syscall? One problem is that some vendors use proprietary SMC calling convention, so the kernel might have to reconstruct the contents of general-purpose registers faithfully as they were when the SMC was being invoked, to forward correct parameters to secure world. Regards, Yanyan From: yadong.limailto:yadong.li@horizon.ai Sent: Friday, 6 August 2021 6:00 PM To: devel@sel4.systemsmailto:devel@sel4.systems Subject: [seL4] seL4 how to access el3 secure world on ARM platfrom Hi： We want to create component driver who need to access ARM el3 secure world to read/write hardware register. But I found that seL4 did not offer capability to call smc function for component of native world. Which cap that already existed can offer the syscall or create new smc cap ? Is there some plan to support it ? Thank you very much. _______________________________________________ Devel mailing list -- devel@sel4.systems To unsubscribe send an email to devel-leave@sel4.systems