1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Simple xorshift PRNG
4  *   see http://www.jstatsoft.org/v08/i14/paper
5  *
6  * Copyright (c) 2012 Michael Walle
7  * Michael Walle <michael@walle.cc>
8  */
9 
10 #include <common.h>
11 #include <rand.h>
12 
13 static unsigned int y = 1U;
14 
rand_r(unsigned int * seedp)15 unsigned int rand_r(unsigned int *seedp)
16 {
17 	*seedp ^= (*seedp << 13);
18 	*seedp ^= (*seedp >> 17);
19 	*seedp ^= (*seedp << 5);
20 
21 	return *seedp;
22 }
23 
rand(void)24 unsigned int rand(void)
25 {
26 	return rand_r(&y);
27 }
28 
srand(unsigned int seed)29 void srand(unsigned int seed)
30 {
31 	y = seed;
32 }
33