TDA4VM: How to uncache an address range?

BTW:
How to uncacheable an address range in linux?

Hi Eason,

On which core, do you want to make this region as non-cached? gCslR5MpuCfg is for R5F, so do you want to change it for R5F? You can find the region configuration for this memory region, which most likely marked as cached, you can mark it as non-cached here. 

Regards,

Brijesh

Hi Brijesh

Brijesh Jadav said:

On which core, do you want to make this region as non-cached? gCslR5MpuCfg is for R5F, so do you want to change it for R5F?

Yes ,I want to change it for R5F and linux.

Brijesh Jadav said:

You can find the region configuration for this memory region, which most likely marked as cached, you can mark it as non-cached here. 

I don't want to set it in mpu_config, I want to use api function to set it.
And which API I can use in R5F?
And how to set it in linux?

Best Regards
Eason

Hi Eason,

On R5F, it has to be done in MPU settings only. We dont have API to change it at runtime. 

Btw, why do you want to change it at runtime? 

Regards,

Brijesh

Hi Brijesh

Brijesh Jadav said:

Btw, why do you want to change it at runtime?

Because I am an xip project, retaining MPU init in the startup code will cause the program to crash, so I have to skip mpu init in the startup code.
Link: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1447338/tda4vm-xip-using-dummy-app-boot-failed/

And now i want to use ipc between linux and mcu1_0,  but the communication between linux and mcu1_0 is not normal:
Link:  https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1472917/tda4vm-linux-and-mcu1_0-ipc-communication-error/ 

I have two doubts now: 1. There is no mailbox unless it is interrupted. 2. The vring buffer has cache.

Best Regards
Eason

Hi Eason,

If you have not enabled MPU, then everything will be non-cached, and vring buffer is typically non-cached, so this should not issue due to caching. I would suggest to look for another suspect. 

Btw, why does it crash when mpu init is done in startup code? Is there a specific reason for it?

Regards,

Brijesh

Hi Brijesh

Brijesh Jadav said:

If you have not enabled MPU, then everything will be non-cached, and vring buffer is typically non-cached, so this should not issue due to caching. I would suggest to look for another suspect. 

I solved it.

Brijesh Jadav said:

Btw, why does it crash when mpu init is done in startup code? Is there a specific reason for it?

I can not find the reason.

Best Regards
Eason