u-boot-brain/lib/rand.c
Simon Glass 840ef4d43b common: Move random-number functions into their own header
Create a new rand.h header file and move functions into it, to reduce
the size of common.h

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
2019-12-02 18:23:07 -05:00

33 lines
497 B
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Simple xorshift PRNG
* see http://www.jstatsoft.org/v08/i14/paper
*
* Copyright (c) 2012 Michael Walle
* Michael Walle <michael@walle.cc>
*/
#include <common.h>
#include <rand.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;
}