Processor Expert SoftwareのトピックMPU configuration and access permissions

MPU configuration and access permissions

morganRo — Mon, 23 Jan 2023 11:47:47 GMT

Hi everyone,

I need some help,

I'm working on a software and I need to separate some software item each other.

So i'm thinking about different section in flash memory. But, I need to protect this section, software item A should not interact with software item B unless by getter and setter.

So I understand region configuration and MPU configuration but I don't understand Access Permission. (Priviliged and Unprivileged)

Can someone explain me this or some code example, documentation etc..

Thank you for the help,

Morgan

Re: MPU configuration and access permissions

_Leo_ — Mon, 23 Jan 2023 18:05:46 GMT

Can you tell us which MCU are you using please?

Re: MPU configuration and access permissions

morganRo — Tue, 24 Jan 2023 09:32:58 GMT

I'm using the IMXRT1061 MCU. Actually, I figured out how to deal with. But i still try to implement protection memory, RO in flash (split in three section) is OK. But now I want to mirror in RAM to implement correctly variable. Thanks, Morgan

Re: MPU configuration and access permissions

morganRo — Thu, 26 Jan 2023 14:06:10 GMT

Hi,

I don't figured out how to active privileged / unprivileged permissions. For example, if i split SRAM_DTC in two section, how can I protection write between this two section?

Re: MPU configuration and access permissions

jingpan — Tue, 31 Jan 2023 08:37:09 GMT

Hi @morganRo ,

You can refer to this guide. RT device follow this guide. But it seems there isn't other document or example.

https://developer.arm.com/documentation/dui0646/c/Cortex-M7-Peripherals/Optional-Memory-Protection-Unit?lang=en

Regards,

Jing