ref: 4cbb6fc715320e648bb452c7449ed3de7d60e95c 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; }