ref: 1cb466d417a9911484a6e097b78c53633e07076a dir: /sys/src/ape/lib/bsd/nptohl.c/
unsigned long nptohl(void *p) { unsigned char *up; unsigned long x; up = p; x = (up[0]<<24)|(up[1]<<16)|(up[2]<<8)|up[3]; return x; }