ref: c1fbc2fd96cb4e10f2ac741b5c2a66ddc85822eb
dir: /sys/src/libauthsrv/nvcsum.c/
#include <u.h>
#include <libc.h>
#include <auth.h>
uchar
nvcsum(void *vmem, int n)
{
	uchar *mem, sum;
	int i;
	sum = 9;
	mem = vmem;
	for(i = 0; i < n; i++)
		sum += mem[i];
	return sum;
}