MicroAPRS/bertos/algo/rand.c

53 lines
1.7 KiB
C

/**
* \file
* <!--
* This file is part of BeRTOS.
*
* Bertos is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* As a special exception, you may use this file as part of a free software
* library without restriction. Specifically, if other files instantiate
* templates or use macros or inline functions from this file, or you compile
* this file and link it with other files to produce an executable, this
* file does not by itself cause the resulting executable to be covered by
* the GNU General Public License. This exception does not however
* invalidate any other reasons why the executable file might be covered by
* the GNU General Public License.
*
* Copyright 2006 Develer S.r.l. (http://www.develer.com/)
* Copyright 1999 Bernie Innocenti <bernie@codewiz.org>
*
* -->
*
* \brief Very simple rand() algorithm.
*
* \author Bernie Innocenti <bernie@codewiz.org>
*/
#include "rand.h"
/**
* This would really belong to libc
*/
int rand(void)
{
static unsigned long seed;
/* Randomize seed */
seed = (seed ^ 0x4BAD5A39UL) + 6513973UL;
return (int)(seed>>16);
}