Fix PDE/PTE definitions, header cleanup

- Fixes PDE/PTE definitions in kernel/paging.h
- removes memset declaration from kernel/utils.h, uses klibc string.h as
needed

kernel/paging.c

@@ -1,21 +1,17 @@
-#include "paging.h"
-#include "io.h"
 #include <stdint.h>
-#include <stddef.h>
+#include <string.h>
+#include "io.h"
+#include "paging.h"
 
 page_directory_entry_t *page_directory = (page_directory_entry_t *)0x200000;
 page_table_entry_t     *page_table     = (page_table_entry_t *)0x201000;
-page_table_entry_t     *heap_page_table = (page_table_entry_t *)0x202000;
 
 // Helper function to set up the page directory entry
 void set_page_directory(page_directory_entry_t *dir) {
-    for (int i = 0; i < PAGE_DIRECTORY_SIZE; i++) {
+    // Set first PDE
-        dir[i].present = 0;
-    }
     dir[0].present = 1;
     dir[0].rw = 1;
-    dir[0].user = 0;
+    dir[0].addr = (uint32_t)page_table >> 12;
-    dir[0].frame = (uint32_t)page_table >> 12;
 }
 
 // Helper function to set up the page table entry
@@ -23,12 +19,8 @@ void set_page_table(page_table_entry_t *table) {
     for (int i = 0; i < PAGE_TABLE_SIZE; i++) {
         // Set up page table entries with identity mapping
         table[i].present = 1;
-        table[i].rw = 1;          // Read/Write
+        table[i].rw = 1;        // Read/Write
-        table[i].user = 0;        // Kernel mode
+        table[i].addr = i;      // Identity mapping
-        table[i].write_through = 0;
-        table[i].cache_disabled = 0;
-        table[i].accessed = 0;
-        table[i].frame = i;       // Identity mapping
     }
 }
 
@@ -47,26 +39,13 @@ void enable_paging() {
 
 // Initialize paging: set up the page directory and enable paging
 void paging_init() {
+    // Zero out the tables
+    memset(page_directory, 0x00, PAGE_DIRECTORY_SIZE * sizeof *page_directory);
+    memset(page_table, 0x00, PAGE_TABLE_SIZE * sizeof *page_table);
+
     // Set up identity-mapped page directory + table
     set_page_directory(page_directory);
     set_page_table(page_table);
 
-    // === Set up heap mapping at 0xC0100000 ===
-    for (int i = 0; i < PAGE_TABLE_SIZE; i++) {
-        heap_page_table[i].present = 1;
-        heap_page_table[i].rw = 1;
-        heap_page_table[i].user = 0;
-        heap_page_table[i].write_through = 0;
-        heap_page_table[i].cache_disabled = 0;
-        heap_page_table[i].accessed = 0;
-        heap_page_table[i].frame = (256 + i); // Start physical heap at 1MB (256*4KB = 1MB)
-    }
-
-    // Index 772 = 0xC0100000 / 4MB
-    page_directory[772].present = 1;
-    page_directory[772].rw = 1;
-    page_directory[772].user = 0;
-    page_directory[772].frame = (uint32_t)heap_page_table >> 12;
-
     enable_paging();
 }

kernel/paging.h

@@ -10,31 +10,31 @@
 
 // Page Directory and Page Table structure
 typedef struct {
-    uint32_t present : 1;  // Present bit (1: page is present in memory)
+    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 rw : 1;                // Read-Write bit (1: page is read-write)
-    uint32_t user : 1;     // User-supervisor bit (1: user mode access)
+    uint32_t user : 1;              // User-supervisor bit (1: user mode access)
-    uint32_t write_through : 1;  // Write-through cache
+    uint32_t write_through : 1;     // Write-through cache
-    uint32_t cache_disabled : 1; // Cache disabled
+    uint32_t cache_disabled : 1;    // Cache disabled
-    uint32_t accessed : 1;        // Accessed bit
+    uint32_t accessed : 1;          // Accessed bit
-    uint32_t reserved : 1;        // Reserved bit
+    uint32_t dirty : 1;             // Dirty bit
-    uint32_t page_size : 1;       // Page size (0: 4KB, 1: 4MB)
+    uint32_t attribute : 1;         // Page size (0: 4KB, 1: 4MB)
-    uint32_t global : 1;           // Global page (can be used across different processes)
+    uint32_t global : 1;            // Global page (can be used across different processes)
-    uint32_t available : 3;        // Available bits for the system
+    uint32_t reserved : 3;          // Unused
-    uint32_t frame : 20;           // Frame address (physical address)
+    uint32_t addr : 20;             // Page frame address (physical address)
 } __attribute__((packed)) page_table_entry_t;
 
 // Define page directory entry
 typedef struct {
-    uint32_t present : 1;
+    uint32_t present : 1;           // Present bit (1: PTE is present in memory)
-    uint32_t rw : 1;
+    uint32_t rw : 1;                // Read-Write bit (1: pages are read-write)
-    uint32_t user : 1;
+    uint32_t user : 1;              // User-supervisor bit (1: user mode access)
-    uint32_t write_through : 1;
+    uint32_t write_through : 1;     // Write-through cache
-    uint32_t cache_disabled : 1;
+    uint32_t cache_disabled : 1;    // Cache disabled
-    uint32_t accessed : 1;
+    uint32_t accessed : 1;          // Accessed bit
-    uint32_t reserved : 1;
+    uint32_t available : 1;         // Unused
-    uint32_t zero : 5;           // Must be zero for page directory
+    uint32_t page_size : 1;         // Page size (0: 4KB, 1: 4MB)
-    uint32_t reserved_2 : 7;     // Reserved bits
+    uint32_t available_2 : 4;       // Unused
-    uint32_t frame : 20;         // Frame address of the page table
+    uint32_t addr : 20;             // Page table address
 } __attribute__((packed)) page_directory_entry_t;
 
 extern page_directory_entry_t *page_directory;

kernel/threading.c

@@ -1,9 +1,8 @@
+#include <stdbool.h>
+#include <string.h>
 #include "malloc.h"
 #include "print.h"
 #include "threading.h"
-#include "types.h"
-#include "utils.h"
-#include <stdint.h>
 
 #define MAX_THREADS 16           // Maximum number of threads
 #define THREAD_STACK_SIZE 8192   // Stack size for each thread

kernel/utils.h

@@ -11,6 +11,4 @@ char* itoa(int value, char* str, int base);
 // Convert unsigned integer to string (base is typically 10, 16, etc.)
 char* utoa(unsigned int value, char* str, int base);
 
-void *memset(void *dest, int value, size_t len);
-
 #endif // UTILS_H