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