Protected Mode

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In computing, protected mode, also called protected virtual address mode, is an operational mode of x86-compatible central processing units (CPU). It allows system software to utilize features such as virtual memory, paging, safe multi-tasking, and other features designed to increase an operating system's control over application software. When a processor that supports x86 protected mode is powered on, it begins executing instructions in real mode, in order to maintain backwards compatibility with earlier x86 processors. Protected mode may only be entered after the system software sets up several descriptor tables and enables the Protection Enable (PE) bit in the Control Register 0 (CR0).

Pagina's: 92, Paperback, Betascript Publishers