A question about s32k144 MPU

[pangyun]

My configuration is as follows：

Code:

(void)MPU_EnableRegion(&mpu_pal_config_1_Instance, 3U, false);

//test = *((uint32_t *)ADDRESS_PROTECT);

Results:

There is no code to read,but it will always go to "void HardFault_Handler(void)".

Change the configuration:

I only changed the address.It will be ok! I am confused.

Please tell me the reason,thank you!

[danielmartynek]

Hi @pangyun,

Please compress the entire project into a .zip file and attach it either here or to the support ticket.

[pangyun]

Here my project, you can test, thank you!

[danielmartynek]

Thanks @pangyun for the project.

I just tested it.

First, I compiled it into the flash, because you were testing it in SRAM

Then I changed 

(void)MPU_EnableRegion(&mpu_pal_config_1_Instance, 2U, false);

to

(void)MPU_EnableRegion(&mpu_pal_config_1_Instance, 3U, false);

So that the descriptor 3 that allows the READ access is disabled only.

After debugging I see that the fault is at 0x2F5C.

This is because the code of MPU_GetError() uses a LDR instruction to load R0 with the value at 0x2F5C - so this is a read operation. Execution of the code in the Flash is allowed by the MPU but reading is not.

Regards,

Daniel

[pangyun]

How can I determine which addresses can be set as read disabled and which addresses cannot be set as read disabled to ensure the normal operation of my program

[pangyun]

Thank you for your test,but now how can I ensure my project runs normally while preventing flash from being read.

[pangyun]

You disabled the descriptor that grants the core access to the flash region,

and the read operation is blocked, but  the problem also exist,why

[danielmartynek]

Hi @pangyun,

Can you please share the project so that I can test it?

What do you see in S32_SCB_CFSR and BFAR registers?

Thank you,

BR, Daniel

[pangyun]

My project's name  is "mpu_pal_memory_protection_s32k144"  from the example.I only change the adress in the MPU configuration and some code in main.c, I use Debug_Flash,, here‘s  the MPU configuration and the code I changed in main.c, you can test.Thank you!