Add rand/rand_r/srand functions for generating pseudo-random bytes.

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Jordan Crouse <jordan.crouse@amd.com>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@3222 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

4 files changed, 61 insertions, 0 deletions

diff --git a/payloads/libpayload/LICENSES b/payloads/libpayload/LICENSES
index d81eb72636..191ad79950 100644
--- a/payloads/libpayload/LICENSES
+++ b/payloads/libpayload/LICENSES
@@ -66,6 +66,12 @@ holders, and the exact license terms that apply.
   Original files: lib/libalias/alias_util.c, function LibAliasInternetChecksum()
   Current version we use: CVS revision 1.15 2004/07/06 12:13:28
 
+* libc/rand.c: 3-clause BSD license
+  Source: OpenBSD
+          http://www.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/rand.c
+  Original files: src/lib/libc/stdlib/rand.c
+  Current version we use: CVS revision 1.9 2005/8/8 08:05:37
+
 * libc/memory.c: 3-clause BSD license
   Source: HelenOS, http://www.helenos.eu
           svn checkout svn://svn.helenos.eu/HelenOS/trunk HelenOS
diff --git a/payloads/libpayload/include/libpayload.h b/payloads/libpayload/include/libpayload.h
index 2cdb0d00f6..b74fbfeab2 100644
--- a/payloads/libpayload/include/libpayload.h
+++ b/payloads/libpayload/include/libpayload.h
@@ -53,6 +53,8 @@
 #define BYTE_ORDER	BIG_ENDIAN
 #endif
 
+#define RAND_MAX 0x7fffffff
+
 /* Some NVRAM byte definitions */
 #define NVRAM_RTC_SECONDS        0
 #define NVRAM_RTC_MINUTES        2
diff --git a/payloads/libpayload/libc/Makefile.inc b/payloads/libpayload/libc/Makefile.inc
index ee64b60644..44975a6a14 100644
--- a/payloads/libpayload/libc/Makefile.inc
+++ b/payloads/libpayload/libc/Makefile.inc
@@ -29,3 +29,4 @@
 
 TARGETS-y += libc/malloc.o libc/printf.o libc/console.o libc/string.o
 TARGETS-y += libc/memory.o libc/ctype.o libc/ipchecksum.o libc/lib.o
+TARGETS-y += libc/rand.o
diff --git a/payloads/libpayload/libc/rand.c b/payloads/libpayload/libc/rand.c
new file mode 100644
index 0000000000..d490809119
--- /dev/null
+++ b/payloads/libpayload/libc/rand.c
@@ -0,0 +1,52 @@
+/*
+ * This file is part of the libpayload project.
+ *
+ * It was originally taken from the OpenBSD project.
+ *
+ * Copyright (c) 1990 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.
+ */
+
+#include <libpayload.h>
+
+static unsigned int next = 1;
+
+int rand_r(unsigned int *seed)
+{
+	*seed = *seed * 1103515245 + 12345;
+	return (*seed % ((unsigned int)RAND_MAX + 1));
+}
+
+int rand(void)
+{
+	return (rand_r(&next));
+}
+
+void srand(unsigned int seed)
+{
+	next = seed;
+}