I am new to FreeRTOS.
I wonder if FreeRTOS has any backup scheme for the power failure.
Or if is it not for the power failure, dose it have any backup scheme?
Not quite certain what you are asking about. To provide backup power for a system would need something in hardware, while FreeRTOS is software, If you just want an 'Orderly Shutdown', then you could do this with an application using FreeRTOS, but what is an 'Orderly Shuttdown' is very application dependent, so there isn't anything directly built into FreeRTOS to do this.
I thought usually OS has an backup policy like saving data to non volatile memory periodically to protect data from sudden power off..
So I was wondering if FreeRTOS also has something related about backup scheme.
For example saving SRAM data to NVM...?
Can't say that I know of any OS that does that (some applications will checkpoint themselves like that).
Some OS's will have a feature that on an empending power loss will save all of memory and shut down.
I would think that such a feature will have serious problems for a RTOS (or even a non-RT OS) as to be effective you would need to stop all processing while you are saving to make it a consistant record of the state of the system at a point in time,