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Fix PDE/PTE definitions, header cleanup

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- Fixes PDE/PTE definitions in kernel/paging.h
- removes memset declaration from kernel/utils.h, uses klibc string.h as
needed
This commit is contained in:
vmttmv
2026-01-12 03:48:02 +02:00
committed by Borna Šoštarić
parent b3831b6c69
commit c805d24dd0
4 changed files with 107 additions and 126 deletions
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43
kernel/paging.c
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@@ -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++) {
dir[i].present = 0;
}
// Set first PDE
dir[0].present = 1;
dir[0].rw = 1;
dir[0].user = 0;
dir[0].frame = (uint32_t)page_table >> 12;
dir[0].addr = (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].user = 0; // Kernel mode
table[i].write_through = 0;
table[i].cache_disabled = 0;
table[i].accessed = 0;
table[i].frame = i; // Identity mapping
table[i].rw = 1; // Read/Write
table[i].addr = 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();
}