48 lines
1.3 KiB
C
48 lines
1.3 KiB
C
#pragma once
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#include "common.h"
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#include "isr.h"
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#include <stdint.h>
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typedef struct page
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{
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uint32_t present : 1; // page present in memory
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uint32_t rw : 1; // ro if clear, rw if set
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uint32_t user : 1; // supervisor level only if clear
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uint32_t accessed : 1; // has been accessed since last referesh
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uint32_t dirty : 1; // has been written to since last refresh
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uint32_t unused : 7; // reserved and unused bits
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uint32_t frame : 20; // frame address (right shift 12 bits)
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} page_t;
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typedef struct page_table
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{
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page_t pages[1024];
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} page_table_t;
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typedef struct
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{
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// array of pointers to pagetables
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page_table_t *tables[1024];
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// array of pointers to tables above but at the *physical* loc
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// so they can be loaded into cr3
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uint32_t tablesPhysical[1024];
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uint32_t physicalAddr;
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} page_directory_t;
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// sets up paging
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void initialize_paging(void);
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// causes the specified page directory to be loaded
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// into the cr3 register
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void switch_page_directory(page_directory_t *new);
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// retrieves a pointer to the page requires
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// if make == 1, if the pagetable in which page
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// should reside inst there create it
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page_t *get_page(uint32_t address, int make, page_directory_t *dir);
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// handler for page faults
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void page_fault(registers_t *regs);
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