[rng] Add entropy sample generator

Allow a list of raw noise samples to be generated for offline
analysis.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/tests/entropy_sample.c

@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/** @file
+ *
+ * Entropy sampling
+ *
+ */
+
+#include <stdio.h>
+#include <ipxe/entropy.h>
+#include <ipxe/test.h>
+
+/** Total number of test samples */
+#define SAMPLE_COUNT 65536
+
+/** Number of samples per block */
+#define SAMPLE_BLOCKSIZE 256
+
+/**
+ * Generate entropy samples for external testing
+ *
+ */
+static void entropy_sample_test_exec ( void ) {
+	static noise_sample_t samples[SAMPLE_BLOCKSIZE];
+	unsigned int i;
+	unsigned int j;
+	int rc;
+
+	/* Collect and print blocks of samples */
+	for ( i = 0 ; i < ( SAMPLE_COUNT / SAMPLE_BLOCKSIZE ) ; i++ ) {
+
+		/* Collect one block of samples */
+		entropy_enable();
+		for ( j = 0 ; j < SAMPLE_BLOCKSIZE ; j++ ) {
+			rc = get_noise ( &samples[j] );
+			ok ( rc == 0 );
+		}
+		entropy_disable();
+
+		/* Print out sample values */
+		for ( j = 0 ; j < SAMPLE_BLOCKSIZE ; j++ ) {
+			printf ( "SAMPLE %d %d\n", ( i * SAMPLE_BLOCKSIZE + j ),
+				 samples[j] );
+		}
+	}
+}
+
+/** Entropy sampling self-test */
+struct self_test entropy_sample_test __self_test = {
+	.name = "entropy_sample",
+	.exec = entropy_sample_test_exec,
+};