mm: add get_page_dir & set_page_dir

include/paging.h

@@ -39,6 +39,8 @@ extern uint32_t *kpage_dir;
 
 //paging.c
 void grub_memory_map(unsigned int magic, struct multiboot_info* mbi);
+uint32_t* get_page_dir();
+void set_page_dir(uint32_t new_page_dir);
 void enablePaging();
 void loadPageDirectory(uint32_t* page_directory);
 

src/mm/paging.c

@@ -112,6 +112,17 @@ void grub_memory_map(unsigned int magic, struct multiboot_info* mbi)
     }
 }
 
+uint32_t* get_page_dir()
+{
+    uint32_t cr3_value;
+    asm volatile("mov %%cr3, %0" : "=r" (cr3_value));
+    return (uint32_t*) cr3_value;
+}
+
+void set_page_dir(uint32_t new_page_dir) {
+    asm volatile("mov %0, %%cr3" : : "r" (new_page_dir));
+}
+
 void enablePaging() {
     asm volatile (
         "mov %%cr0, %%eax\n"