The C7X DSP is a 64-bit processor with an MMU, but usually a real-time operating system is run. The current SDK version before 8.0 runs the SYSBIOS real-time operating system provided by TI. For details, see the TI-RTOS Kernel (SYS/BIOS) User’s Guide，Subsequent SDK versions run the Freertos operating system by default. For details, see PDK4.2. The code related to the application layer is not highly dependent on the underlying operating system, so there is no need to upgrade the system to a new version when doing a TIDL upgrade. The main function of the entire operating system is located in ti-processor-sdk-rtos-j721e-evm-08_04_00_02/vision_apps/platform/j721e/rtos/c7x_1/main.c

Figure 1-1 C7X OS Main Function