What are the advantages of using CMSIS layer on top of the FreeRTOS layer?

[jg_spitfire]

Hi, I have worked with FreeRTOS in a project with other board brand and to implement the FreeRTOS functions we followed these guides https://www.freertos.org/Documentation/RTOS_book.html which are great, now with ST I realize you can include a layer (CMSIS) on top of the FreeRTOS layer, does exists a detailed guide of these CMSIS functions and when to use it?, what are the advantages and disadvantages of use this layer?

[Loic CHOSSAT]

CMSIS RTOS layer aims to ease portability across RTOS. If you implement FreeRTOS though CMSIS RTOS, it will be faster to port your project to another RTOS is needed. CMSIS RTOS option is required for the RTOS kernels supported in STM32Cube.