extern print_string_function %macro print_string 2+ [section boot.data] %%str: db %2, 0 __SECT__ mov esi, %%str mov bl, %1 call print_string_function %endmacro extern print_newline_function %macro print_newline 0 call print_newline_function %endmacro extern clear_screen_function %macro clear_screen 0 call clear_screen_function %endmacro