On 20 September 2013 06:55, Mj Embd <mj.embd@xxxxxxxxx> wrote: > Hello Andre, > I need a bit clarification here, if you read the next line after the line > you have quoted. It clearly says that you can use a MCR to change from > Secure to NS in Monitor Mode No, it's not saying that, because Monitor mode is always Secure: this is exactly why an MCR to change SCR.NS is OK only in Monitor mode -- it doesn't change from Secure to Non-Secure. Only when you do an exception-return to leave Monitor mode will you drop into the NonSecure world. > "Use an MCR instruction that writes SCR.NS to change from Secure to > Non-secure state. This means ARM recommends that software does not alter > SCR.NS in any mode except Monitor mode. ARM deprecates changing SCR.NS in > any other mode." The text says "don't change from Secure to NonSecure by flipping SCR.NS". It then lays out the corollary: the only time you then can change SCR.NS is when it won't switch from Secure to NonSecure, which is when you're in Monitor mode. -- PMM _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
