多选题

Which descriptions about microkernel-...

Question

Which descriptions about microkernel-based OS is/are NOT TURE?

A. file system and driver is not part of kernel

B. it’s must be RTOS (real-time OS)

C. more effective in context switching and more secure than Monolithic kernel OS

D. QNX, L4Linux, Mach and Symbian are all the Microkernel OS