diff --git a/core/exception_handler.c b/core/exception_handler.c
index 64aeca0..a948fba 100644
--- a/core/exception_handler.c
+++ b/core/exception_handler.c
@@ -11,6 +11,11 @@ __attribute__((interrupt)) void print_handler(struct interrupt_frame *frame, ulo
         (void)error_code;
 }
 
+
+// c.f. https://wiki.osdev.org/Paging#Handling
+// error_code   bit0: Present ?
+//              bit1: Trying to write ?
+//              bit2: User page try to access?
 __attribute__((interrupt)) void pagefault_handler(struct interrupt_frame *frame, ulong error_code){
         printStringDetails("PAGE FAULT", RED, BLACK, 0, VGA_HEIGHT - 1);
         printIntDetails(error_code, RED, BLACK, 11, VGA_HEIGHT - 1);