Is it possible to write the CCM RAM with STM32 USART bootloader?

In AN3155 the USART STM32 bootloader is described and there is a command “Write Memory�? which can write to any valid memory address i.e. RAM, Flash memory, or option byte area.

Is it possible to write the CCM RAM with the bootloader? 

If yes, which (command line) tools does support this?

stm32flash raises an error