u-boot/lib/rand.c
Wolfgang Denk 1a4596601f Add GPL-2.0+ SPDX-License-Identifier to source files
Signed-off-by: Wolfgang Denk <wd@denx.de>
[trini: Fixup common/cmd_io.c]
Signed-off-by: Tom Rini <trini@ti.com>
2013-07-24 09:44:38 -04:00

32 lines
482 B
C

/*
* Simple xorshift PRNG
* see http://www.jstatsoft.org/v08/i14/paper
*
* Copyright (c) 2012 Michael Walle
* Michael Walle <michael@walle.cc>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
static unsigned int y = 1U;
unsigned int rand_r(unsigned int *seedp)
{
*seedp ^= (*seedp << 13);
*seedp ^= (*seedp >> 17);
*seedp ^= (*seedp << 5);
return *seedp;
}
unsigned int rand(void)
{
return rand_r(&y);
}
void srand(unsigned int seed)
{
y = seed;
}