fix: a bunch of stuff related to multitasking

src/multitasking/switch_to_task.s

@@ -23,6 +23,8 @@ switch_to_task:
 	mov esp, [current_task] // esp
 	mov eax, [current_task+4] // esp0
 	mov ebx, [current_task+8] // cr3
+	mov edi, [current_task+12] // page_directory
+	mov [page_directory], edi
 	mov [TSS+4], eax // tss.esp0
 	mov ecx, cr3
 
@@ -41,4 +43,6 @@ switch_to_task:
 	pop ebp
 	pop ebx
 
+	sti
+
 	ret