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remarkable-uboot/net/net_rand.c

69 lines
1.2 KiB
C

/*
* Based on LiMon - BOOTP.
*
* Copyright 1994, 1995, 2000 Neil Russell.
* (See License)
* Copyright 2000 Roland Borde
* Copyright 2000 Paolo Scaffardi
* Copyright 2000-2004 Wolfgang Denk, wd@denx.de
*/
#include <common.h>
#include <net.h>
#include "net_rand.h"
static ulong seed1, seed2;
void srand_mac(void)
{
ulong tst1, tst2, m_mask;
ulong m_value = 0;
int reg;
unsigned char bi_enetaddr[6];
/* get our mac */
eth_getenv_enetaddr("ethaddr", bi_enetaddr);
debug("BootpRequest => Our Mac: ");
for (reg = 0; reg < 6; reg++)
debug("%x%c", bi_enetaddr[reg], reg == 5 ? '\n' : ':');
/* Mac-Manipulation 2 get seed1 */
tst1 = 0;
tst2 = 0;
for (reg = 2; reg < 6; reg++) {
tst1 = tst1 << 8;
tst1 = tst1 | bi_enetaddr[reg];
}
for (reg = 0; reg < 2; reg++) {
tst2 = tst2 | bi_enetaddr[reg];
tst2 = tst2 << 8;
}
seed1 = tst1^tst2;
/* Mirror seed1*/
m_mask = 0x1;
for (reg = 1; reg <= 32; reg++) {
m_value |= (m_mask & seed1);
seed1 = seed1 >> 1;
m_value = m_value << 1;
}
seed1 = m_value;
seed2 = 0xb78d0945;
}
unsigned long rand(void)
{
ulong sum;
/* Random Number Generator */
sum = seed1 + seed2;
if (sum < seed1 || sum < seed2)
sum++;
seed2 = seed1;
seed1 = sum;
return sum;
}