Linux/PROCESSOR-SDK-AM335X: Read shared memory written by the PRU from the kernel

Diego Juara

Tool/software: Linux

Hello everyone,

In a beaglebone black, I have a program that enable the PRU and load the code on them, they write in a shared memory I can access from userspace (and read the data correctly). But the point is that I want to read that memory from kernel space, and I don't know if it's possible, or there are some limitations due to memory restrictions or something like that.

Thanks in advanced.

over 8 years ago

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Hi Diego,

Do you use AM335x TI PSDK v4?

Can you provide more details regarding this share memory? Is it DDR3 memory or OCMC RAM memory or else? How exactly you access that memory from user space?

Regards,
Pavel

0 Diego Juara over 8 years ago in reply to Pavel Botev

Prodigy 40 points

Hi Pavel,

the memory is DDR RAM, and I access this memory previusly mapping that area and reading it with a pointer after the PRU had written it.

Diego.

0 Pavel Botev over 8 years ago in reply to Diego Juara

TI__Guru**** 170625 points

Diego,

Do yo use ti-processor-sdk-linux-am335x-evm-04.00.00.04-Linux-x86-Install.bin or else?

Do you need to access DDR RAM at kernel level from PRU core directly?

You can access DDR RAM at kernel level with the EDMA kernel API:

processors.wiki.ti.com/.../AM335x_EDMA_Driver's_Guide
processors.wiki.ti.com/.../EDMA_sample_test_application
processors.wiki.ti.com/.../AM335x-PSP_04.06.00.11_Features_and_Performance_Guide

Regards,
Pavel

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Linux/PROCESSOR-SDK-AM335X: Read shared memory written by the PRU from the kernel