Protection


  • Ring protection - lower number => higher privilege level
    • Ring 0: Kernel, Device Drivers, Filesystems
    • Ring 1: Not used
    • Ring 2: "IOPL" -- mostly print and video
    • Ring 3: Everything else
  • I/O Adressing requires Ring 2 or VDM
  • Processes have their own virtual address space (except for explicitly shared memory)



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