AM62P: Switch the linux version to rt-Linux

Hi,

The thread owner is out of office till until week of Feb 17. Please ping the thread if you do not get an update during that week.

Thank you for your patience.

Regards,
Harshith

Hi Harshith,

Sorry to disturb you, but I would like to ask if there are any other experts who can support this issue?  

It was too late after Feb 17th because the client's request for a response was rather urgent. 

Thanks

Hello Shawn,

To provide some additional context: before Linux kernel 6.12, the RT Linux patches were maintained separate from mainline Linux. So the patches had to be added to mainline Linux, tested, modified as needed, etc. We already did all that work for you on kernel branch ti-rt-linux-6.6.y:
https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/log/?h=ti-rt-linux-6.6.y

That kernel branch is the source that is used for the AM62P RT Linux SDK:
https://www.ti.com/tool/download/PROCESSOR-SDK-LINUX-RT-AM62P

Starting in Linux kernel 6.12, the RT Linux patches are merged into mainline Linux for 64-bit processors, and you can use kernel configs to enable or disable RT features in a single branch.

Final note: RT Linux IS NOT A TRUE REAL-TIME SYSTEM. It is a set of tools that allows Linux to become MORE real-time. However, if missing timing once a month will break the customer's system, then you should NOT use RT Linux. Those usecases should use a true RTOS, or implement the logic in hardware circuits. For more information, refer to the AM62Px Multicore academy > System Design > Operating systems:
https://dev.ti.com/tirex/explore/node?isTheia=false&node=A__AeQyGefrI7qyqGJR.b2hjA__AM62P-ACADEMY__fp5YxRM__LATEST

Regards,

Nick

Hi Nick,

I have another question to ask. If the project is to be implemented on RTLinux, are there any resource requirements?  

For example, how much margin should be reserved for cpu, memory and interrupts? 

Thanks

Hi Nick,

Another question: The version we are currently using is as shown in the following picture information. If we want to use RT Linux, what is the most convenient way? 

Thanks

Hello Shawn,

It can be tricky to optimize RT Linux (or even regular Linux) to run exactly the way that you want. You can find the RT optimizations that TI applies (these are kernel configs, applied in addition to the RT Linux patches) in file <path-to-ti-linux-kernel>/kernel/configs/ti_rt.config

For more information, see https://software-dl.ti.com/processor-sdk-linux/esd/AM62PX/10_01_10_04/exports/docs/linux/Foundational_Components_Kernel_Users_Guide.html#using-default-configurations 

I would expect that your margin required for CPU cores, DDR memory, etc will depend much more on your specific usecase than on RT Linux vs regular Linux.

Keep in mind that you can use the AM62Px EVM to emulate what an AM62Px device would look like with a different number of cores. Refer to the AM62Px academy > Porting CPU
https://dev.ti.com/tirex/explore/node?isTheia=false&node=A__AXuxc6fVs.bURueXXG3YCQ__AM62P-ACADEMY__fp5YxRM__LATEST

You can also define different sizes of DDR memory and see how Linux behaves on an EVM doing your target usecase.

Regards,

Nick