From 5b1afe32cf7496acea8182278aca83f59e8384e3 Mon Sep 17 00:00:00 2001 From: Florian Pritz Date: Mon, 11 Feb 2013 22:58:16 +0100 Subject: Make code launchpad/energia compatible Signed-off-by: Florian Pritz --- lib/msp430/random.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) create mode 100644 lib/msp430/random.c (limited to 'lib/msp430/random.c') diff --git a/lib/msp430/random.c b/lib/msp430/random.c new file mode 100644 index 0000000..6b46d5e --- /dev/null +++ b/lib/msp430/random.c @@ -0,0 +1,90 @@ +/*- + * Copyright (c) 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * Posix rand_r function added May 1999 by Wes Peters . + * + * $Id$ + */ + +/* + * From: +static char sccsid[] = "@(#)rand.c 8.1 (Berkeley) 6/14/93"; +*/ +#ifndef RANDOM_MAX +#define RANDOM_MAX 0x7FFFFFFF +#endif + +#include + +static long +do_random(unsigned long *ctx) +{ + /* + * Compute x = (7^5 * x) mod (2^31 - 1) + * wihout overflowing 31 bits: + * (2^31 - 1) = 127773 * (7^5) + 2836 + * From "Random number generators: good ones are hard to find", + * Park and Miller, Communications of the ACM, vol. 31, no. 10, + * October 1988, p. 1195. + */ + long hi, lo, x; + + x = *ctx; + /* Can't be initialized with 0, so use another value. */ + if (x == 0) + x = 123459876L; + hi = x / 127773L; + lo = x % 127773L; + x = 16807L * lo - 2836L * hi; + if (x < 0) + x += 0x7fffffffL; + return ((*ctx = x) % ((unsigned long)RANDOM_MAX + 1)); +} + + +long +random_r(unsigned long *ctx) +{ + return do_random(ctx); +} + + +static unsigned long next = 1; + +long +random(void) +{ + return do_random(&next); +} + +void +srandom(unsigned long seed) +{ + next = seed; +} + -- cgit v1.2.3-24-g4f1b