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https://github.com/gbowne1/ClassicOS.git
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3b67e81ed0
- Fixes PDE/PTE definitions in kernel/paging.h - removes memset declaration from kernel/utils.h, uses klibc string.h as needed
50 lines
2.1 KiB
C
50 lines
2.1 KiB
C
#ifndef PAGING_H
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#define PAGING_H
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#include <stdint.h>
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#define PAGE_SIZE 4096 // Page size in bytes
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#define PAGE_DIRECTORY_SIZE 1024 // 1024 entries in page directory
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#define PAGE_TABLE_SIZE 1024 // 1024 entries in a page table
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#define KERNEL_HEAP_START 0xC0100000
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// Page Directory and Page Table structure
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typedef struct {
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uint32_t present : 1; // Present bit (1: page is present in memory)
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uint32_t rw : 1; // Read-Write bit (1: page is read-write)
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uint32_t user : 1; // User-supervisor bit (1: user mode access)
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uint32_t write_through : 1; // Write-through cache
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uint32_t cache_disabled : 1; // Cache disabled
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uint32_t accessed : 1; // Accessed bit
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uint32_t dirty : 1; // Dirty bit
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uint32_t attribute : 1; // Page size (0: 4KB, 1: 4MB)
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uint32_t global : 1; // Global page (can be used across different processes)
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uint32_t reserved : 3; // Unused
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uint32_t addr : 20; // Page frame address (physical address)
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} __attribute__((packed)) page_table_entry_t;
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// Define page directory entry
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typedef struct {
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uint32_t present : 1; // Present bit (1: PTE is present in memory)
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uint32_t rw : 1; // Read-Write bit (1: pages are read-write)
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uint32_t user : 1; // User-supervisor bit (1: user mode access)
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uint32_t write_through : 1; // Write-through cache
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uint32_t cache_disabled : 1; // Cache disabled
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uint32_t accessed : 1; // Accessed bit
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uint32_t available : 1; // Unused
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uint32_t page_size : 1; // Page size (0: 4KB, 1: 4MB)
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uint32_t available_2 : 4; // Unused
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uint32_t addr : 20; // Page table address
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} __attribute__((packed)) page_directory_entry_t;
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extern page_directory_entry_t *page_directory;
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extern page_table_entry_t *page_table;
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extern page_table_entry_t *heap_page_table;
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void paging_init(void);
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void set_page_directory(page_directory_entry_t *dir);
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void set_page_table(page_table_entry_t *table);
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void enable_paging(void);
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#endif
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