u-boot-brain/net/net_rand.h
Jimmy Du b044cc1dee net: Get mac address from driver as seed
Previously seeded by obtaining mac addr from env. If mac addr was
never set, rand would output 0. This fix obtains the mac addr
from driver instead.

Signed-off-by: Jimmy Du <jimmy.du@ni.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
2017-08-07 15:18:28 -05:00

44 lines
774 B
C

/*
* Copied from LiMon - BOOTP.
*
* Copyright 1994, 1995, 2000 Neil Russell.
* (See License)
* Copyright 2000 Paolo Scaffardi
*/
#ifndef __NET_RAND_H__
#define __NET_RAND_H__
#include <common.h>
/*
* Return a seed for the PRNG derived from the eth0 MAC address.
*/
static inline unsigned int seed_mac(void)
{
unsigned char enetaddr[ARP_HLEN];
unsigned int seed;
/* get our mac */
memcpy(enetaddr, eth_get_ethaddr(), ARP_HLEN);
seed = enetaddr[5];
seed ^= enetaddr[4] << 8;
seed ^= enetaddr[3] << 16;
seed ^= enetaddr[2] << 24;
seed ^= enetaddr[1];
seed ^= enetaddr[0] << 8;
return seed;
}
/*
* Seed the random number generator using the eth0 MAC address.
*/
static inline void srand_mac(void)
{
srand(seed_mac());
}
#endif /* __NET_RAND_H__ */