HelenOS sources
print_str 664 boot/generic/src/printf_core.c retval = print_str(va_arg(ap, char *), width, precision, flags, ps);
print_str 1509 common/printf/printf_core.c retval = print_str(va_arg(ap, char *), width, precision, flags, ps);
print_str 1509 kernel/generic/common/printf/printf_core.c retval = print_str(va_arg(ap, char *), width, precision, flags, ps);
print_str 1509 uspace/lib/c/common/printf/printf_core.c retval = print_str(va_arg(ap, char *), width, precision, flags, ps);
HelenOS homepage, sources at GitHub