AM62A7: What is the difference between PROCESSOR-SDK-LINUX-RT-AM62A and PROCESSOR-SDK-LINUX-AM62A?

Hello O.H,

As you observed, the 6.12 kernel is the same for both regular Linux and RT Linux for 64-bit processors like AM62Ax. (future readers, note that 32-bit processors like AM335x did NOT get RT Linux support merged into upstream Linux for Linux kernel 6.12)

Since the same kernel is used, we use kernel configs to configure the kernel differently, depending on whether we want RT Linux or regular Linux. You can see that in the Linux SDK docs for building the kernel:
https://software-dl.ti.com/processor-sdk-linux/esd/AM62AX/11_01_07_05/exports/docs/linux/Foundational_Components_Kernel_Users_Guide.html

Configuring the kernel > Using Default Configurations

You'll see that for the TI default settings for RT-Linux, we add ti_rt.config.

$ find -name "ti_rt.config"
./kernel/configs/ti_rt.config

Refer to this file to see all the extra kernel configurations we do to set up RT Linux. Keep in mind that RT Linux tends to be very custom - each customer will usually configure RT Linux to run exactly how they want on their system.

So why does TI still have separate Linux and RT Linux SDKs if it's the same kernel? 

Good question. I will check with the developers.

FYI: RT Linux is NOT an RTOS!! 

RT Linux is MORE deterministic than regular Linux, but RT Linux is NOT a true RTOS. If your usecase will break if Linux misses timing once a year, then I would encourage you to consider a true RTOS, or even programming the logic into circuitry instead of software. For more information, refer to the AM62Ax multicore academy:
Multicore System Design > Operating systems
https://dev.ti.com/tirex/explore/node?isTheia=false&node=A__AcXUebjrS-3qRLoqvS66-A__AM62A-ACADEMY__WeZ9SsL__LATEST 

Regards,

Nick

Why do we still have separate Linux and RT Linux SDKs if it's the same kernel? 

Most parts of the Linux and RT Linux SDKs should be the same for AM62Ax SDK 11.x onwards, other than the filesystems that are packaged within the SDK. But for now, we have Linux SDK and RT Linux SDK as separate packages for several reasons:

1) The yocto build system that we use to generate the filesystems also builds the SDKs separately:
https://git.yoctoproject.org/meta-ti/tree/meta-ti-bsp/recipes-kernel/linux?h=scarthgap-next

2) We do different tests on different SDK flavors (e.g., cyclictest is only done on an RT Linux platform, other tests where overall system performance is more important to customer's usecase are done on regular Linux)

Regards,
Nick