NPORTS
port = (getpid() % NPORTS) + STARTPORT;
for (i = 0; i < NPORTS && res < 0 && errno == EADDRINUSE; i++) {
port = arc4random_uniform(NPORTS) + STARTPORT;
for(i = 0; i < NPORTS; i++) {
for (irq = 0; irq < NPORTS; irq ++) {
#define NGPIO (NPORTS * 32)