new OS

kernel/paging.h

@@ -0,0 +1,47 @@
+#ifndef PAGING_H
+#define PAGING_H
+
+#include <stdint.h>
+
+#define PAGE_SIZE 4096                // Page size in bytes
+#define PAGE_DIRECTORY_SIZE 1024      // 1024 entries in page directory
+#define PAGE_TABLE_SIZE 1024          // 1024 entries in a page table
+
+// Page Directory and Page Table structure
+typedef struct {
+    uint32_t present : 1;  // Present bit (1: page is present in memory)
+    uint32_t rw : 1;       // Read-Write bit (1: page is read-write)
+    uint32_t user : 1;     // User-supervisor bit (1: user mode access)
+    uint32_t write_through : 1;  // Write-through cache
+    uint32_t cache_disabled : 1; // Cache disabled
+    uint32_t accessed : 1;        // Accessed bit
+    uint32_t reserved : 1;        // Reserved bit
+    uint32_t page_size : 1;       // Page size (0: 4KB, 1: 4MB)
+    uint32_t global : 1;           // Global page (can be used across different processes)
+    uint32_t available : 3;        // Available bits for the system
+    uint32_t frame : 20;           // Frame address (physical address)
+} __attribute__((packed)) page_table_entry_t;
+
+// Define page directory entry
+typedef struct {
+    uint32_t present : 1;
+    uint32_t rw : 1;
+    uint32_t user : 1;
+    uint32_t write_through : 1;
+    uint32_t cache_disabled : 1;
+    uint32_t accessed : 1;
+    uint32_t reserved : 1;
+    uint32_t zero : 5;           // Must be zero for page directory
+    uint32_t reserved_2 : 7;     // Reserved bits
+    uint32_t frame : 20;         // Frame address of the page table
+} __attribute__((packed)) page_directory_entry_t;
+
+extern page_directory_entry_t *page_directory;
+extern page_table_entry_t *page_table;
+
+void paging_init(void);
+void set_page_directory(page_directory_entry_t *dir);
+void set_page_table(page_table_entry_t *table);
+void enable_paging(void);
+
+#endif