iPXE
entropy_sample.c
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00001 /*
00002  * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
00003  *
00004  * This program is free software; you can redistribute it and/or
00005  * modify it under the terms of the GNU General Public License as
00006  * published by the Free Software Foundation; either version 2 of the
00007  * License, or any later version.
00008  *
00009  * This program is distributed in the hope that it will be useful, but
00010  * WITHOUT ANY WARRANTY; without even the implied warranty of
00011  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00012  * General Public License for more details.
00013  *
00014  * You should have received a copy of the GNU General Public License
00015  * along with this program; if not, write to the Free Software
00016  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
00017  * 02110-1301, USA.
00018  *
00019  * You can also choose to distribute this program under the terms of
00020  * the Unmodified Binary Distribution Licence (as given in the file
00021  * COPYING.UBDL), provided that you have satisfied its requirements.
00022  */
00023 
00024 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
00025 
00026 /** @file
00027  *
00028  * Entropy sampling
00029  *
00030  */
00031 
00032 #include <stdio.h>
00033 #include <ipxe/entropy.h>
00034 #include <ipxe/test.h>
00035 
00036 /** Total number of test samples */
00037 #define SAMPLE_COUNT 65536
00038 
00039 /** Number of samples per block */
00040 #define SAMPLE_BLOCKSIZE 256
00041 
00042 /**
00043  * Generate entropy samples for external testing
00044  *
00045  */
00046 static void entropy_sample_test_exec ( void ) {
00047         static noise_sample_t samples[SAMPLE_BLOCKSIZE];
00048         unsigned int i;
00049         unsigned int j;
00050         int rc;
00051 
00052         /* Collect and print blocks of samples */
00053         for ( i = 0 ; i < ( SAMPLE_COUNT / SAMPLE_BLOCKSIZE ) ; i++ ) {
00054 
00055                 /* Collect one block of samples */
00056                 rc = entropy_enable();
00057                 ok ( rc == 0 );
00058                 for ( j = 0 ; j < SAMPLE_BLOCKSIZE ; j++ ) {
00059                         rc = get_noise ( &samples[j] );
00060                         ok ( rc == 0 );
00061                 }
00062                 entropy_disable();
00063 
00064                 /* Print out sample values */
00065                 for ( j = 0 ; j < SAMPLE_BLOCKSIZE ; j++ ) {
00066                         printf ( "SAMPLE %d %d\n", ( i * SAMPLE_BLOCKSIZE + j ),
00067                                  samples[j] );
00068                 }
00069         }
00070 }
00071 
00072 /** Entropy sampling self-test */
00073 struct self_test entropy_sample_test __self_test = {
00074         .name = "entropy_sample",
00075         .exec = entropy_sample_test_exec,
00076 };