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U, the user\supervisor bit, controls access to the page based on privilege level. If the bit is set, then the page may be accessed by all; if the bit is not set, however, only the supervisor can access it. |
U, the user\supervisor bit, controls access to the page based on privilege level. If the bit is set, then the page may be accessed by all; if the bit is not set, however, only the supervisor can access it. |
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R, the read and write permissions flag. If the bit is not set, the page is |
R, the read and write permissions flag. If the bit is not set, the page is read only. If the bit is not set, the page is read/write. |
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P, or 'Presence', determines if the page is actually in physical memory at the moment. (eg. if a page only exists on the hard drive, it is not in physical memory.) If a page is called, but not present, a page fault will occur, and the OS should handle it. (See below.) |
P, or 'Presence', determines if the page is actually in physical memory at the moment. (eg. if a page only exists on the hard drive, it is not in physical memory.) If a page is called, but not present, a page fault will occur, and the OS should handle it. (See below.) |
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