ATTR_SYS
if (attr & ATTR_SYS)
((attr | oldattr) & ATTR_SYS) &&
if (de->attr & ATTR_SYS) {
#define ATTR_UNUSED (ATTR_VOLUME | ATTR_ARCH | ATTR_SYS | ATTR_HIDDEN)
#define ATTR_EXT (ATTR_RO | ATTR_HIDDEN | ATTR_SYS | ATTR_VOLUME)