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typedef struct page
{
   u32int present    : 1;   // Page present in memory
   u32int rw         : 1;   // Read-only if clear, readwrite if set
   u32int user       : 1;   // Supervisor level only if clear
   u32int accessed   : 1;   // Has the page been accessed since last refresh?
   u32int dirty      : 1;   // Has the page been written to since last refresh?
   u32int unused     : 7;   // Amalgamation of unused and reserved bits
   u32int frame      : 20;  // Frame address (shifted right 12 bits)
} page_t; 

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typedef struct page
{
	u32int present : 1;  // Page present in memory
	u32int rw : 1;  // Read-only if clear, readwrite if set
	u32int user : 1;  // Supervisor level only if clear
	u32int reserved : 2;  // Reserved bits <-------------- Missing from the first.
	u32int accessed : 1;  // Has the page been accessed since last refresh?
	u32int dirty : 1;  // Has the page been written to since last refresh?
	u32int unused: 5;  // Amalgamation of unused and reserved bits
	u32int frame : 20;  // Frame address (shifted right 12 bits)
} page_t;

Code: Select all

typedef struct page
{
   u32int present    : 1;   // Present bit.
   u32int rw         : 1;   // Read/Write bit.
   u32int user       : 1;   // User/Supervisor bit.
   u32int pwt        : 1;   // Page-level writethrough bit.
   u32int pcd        : 1;   // Page-level cache disable bit.
   u32int accessed   : 1;   // Accessed bit.
   u32int dirty      : 1;   // Dirty bit.
   u32int pat        : 1;   // Page-attribute table bit.
   u32int global     : 1;   // Global bit.
   u32int avl        : 3;   // Available to software bit.
   u32int frame      : 20;  // Physical address.
} page_t;