include support for a simple pseudo number generator

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

2 files changed, 27 insertions, 0 deletions

diff --git a/lib/Makefile b/lib/Makefile
index b072fb6bea..4a33aaa3c0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
 obj-y			+= glob.o
 obj-y			+= notifier.o
 obj-y			+= copy_file.o
+obj-y			+= random.o
 obj-y			+= lzo/
 obj-$(CONFIG_LZO_DECOMPRESS)		+= decompress_unlzo.o
 obj-$(CONFIG_PROCESS_ESCAPE_SEQUENCE)	+= process_escape_sequence.o
diff --git a/lib/random.c b/lib/random.c
new file mode 100644
index 0000000000..352d6bf3f7
--- /dev/null
+++ b/lib/random.c
@@ -0,0 +1,26 @@
+#include <common.h>
+#include <stdlib.h>
+
+static unsigned int random_seed;
+
+#if RAND_MAX > 32767
+#error this rand implementation is for RAND_MAX < 32678 only.
+#endif
+
+unsigned int rand(void)
+{
+	random_seed = random_seed * 1103515245 + 12345;
+	return (random_seed / 65536) % (RAND_MAX + 1);
+}
+
+void srand(unsigned int seed)
+{
+	random_seed = seed;
+}
+
+void get_random_bytes(char *buf, int len)
+{
+	while (len--)
+		*buf++ = rand() % 256;
+}
+