42_KFS/src/memory/memory.c

#include "memory.h"
#include "kprintf.h"
#include "string.h"

#include <stdint.h>

extern void enable_paging(void);
extern void load_page_directory(uint32_t *);

extern uint32_t boot_page_table1;
extern uint32_t boot_page_directory;

// Pour récupérer une entrée spécifique
uint32_t *page_directory = &boot_page_directory;
uint32_t page_table_entries[1024] __attribute__((aligned(4096)));

unsigned long read_cr3()
{
	unsigned long cr3_value;

	// Inline assembly to read CR3
	__asm__ volatile(
	    "mov %%cr3, %0" // Move the value of CR3 into cr3_value
	    : "=r"(
		cr3_value) // Output operand: cr3_value will receive the value
	    :              // No input operands
	    :              // No clobber list
	);

	return cr3_value;
}

static inline void load_cr3(uint64_t cr3_value)
{
	asm volatile("mov %0, %%cr3" ::"r"(cr3_value) : "memory");
}

void init_memory(void)
{
	for (int i = 0; i < 1024; i++)
		page_table_entries[i] = (i << 12) | INIT_FLAGS;
	page_directory[1] = (uint32_t)page_table_entries | INIT_FLAGS;
}