Merge branch 'main' into fix/91-header-cleanup

This commit is contained in:
2026-01-13 07:39:46 -08:00
committed by GitHub
4 changed files with 33 additions and 57 deletions

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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();
}

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@@ -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 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)
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 dirty : 1; // Dirty bit
uint32_t attribute : 1; // Page size (0: 4KB, 1: 4MB)
uint32_t global : 1; // Global page (can be used across different processes)
uint32_t reserved : 3; // Unused
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 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
uint32_t present : 1; // Present bit (1: PTE is present in memory)
uint32_t rw : 1; // Read-Write bit (1: pages are 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 available : 1; // Unused
uint32_t page_size : 1; // Page size (0: 4KB, 1: 4MB)
uint32_t available_2 : 4; // Unused
uint32_t addr : 20; // Page table address
} __attribute__((packed)) page_directory_entry_t;
extern page_directory_entry_t *page_directory;

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

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@@ -9,6 +9,4 @@ 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