diff --git a/ChangeLog b/ChangeLog
index ad4d1f5..6a7100a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -26,6 +26,9 @@
      in the trusted certificate list.
    * Fix bug in mbedtls_x509_crt_parse that caused trailing extra data in the 
      buffer after DER certificates to be included in the raw representation.
+   * Fix issue that caused a hang when generating RSA keys of odd bitlength
+   * Fix bug in mbedtls_rsa_rsaes_pkcs1_v15_encrypt that made null pointer
+     dereference possible.
 
 Changes
    * On ARM platforms, when compiling with -O0 with GCC, Clang or armcc5,
diff --git a/library/rsa.c b/library/rsa.c
index 06f96ef..7c1f658 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -102,7 +102,8 @@
     if( f_rng == NULL || nbits < 128 || exponent < 3 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
-    mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 ); mbedtls_mpi_init( &H ); mbedtls_mpi_init( &G );
+    mbedtls_mpi_init( &P1 ); mbedtls_mpi_init( &Q1 ); 
+    mbedtls_mpi_init( &H ); mbedtls_mpi_init( &G );
 
     /*
      * find primes P and Q with Q < P so that:
@@ -112,14 +113,19 @@
 
     do
     {
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, ( nbits + 1 ) >> 1, 0,
+        MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->P, nbits >> 1, 0,
                                 f_rng, p_rng ) );
 
-        MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, ( nbits + 1 ) >> 1, 0,
+        if( nbits % 2 )
+        {
+            MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, ( nbits >> 1 ) + 1, 0,
                                 f_rng, p_rng ) );
-
-        if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) < 0 )
-            mbedtls_mpi_swap( &ctx->P, &ctx->Q );
+        }
+        else
+        {
+            MBEDTLS_MPI_CHK( mbedtls_mpi_gen_prime( &ctx->Q, nbits >> 1, 0,
+                                f_rng, p_rng ) );
+        }
 
         if( mbedtls_mpi_cmp_mpi( &ctx->P, &ctx->Q ) == 0 )
             continue;
@@ -586,7 +592,8 @@
     if( mode == MBEDTLS_RSA_PRIVATE && ctx->padding != MBEDTLS_RSA_PKCS_V15 )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
-    if( f_rng == NULL )
+    // We don't check p_rng because it won't be dereferenced here
+    if( f_rng == NULL || input == NULL || output == NULL )
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
 
     olen = ctx->len;
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 1cc8256..5ecf868 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2,20 +2,24 @@
 
 # all.sh
 #
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
 # Copyright (c) 2014-2016, ARM Limited, All Rights Reserved
 #
 # Purpose
 #
-# Run all available tests (mostly).
+# To run all tests possible or available on the platform.
 #
-# Warning: includes various build modes, so it will mess with the current
-# CMake configuration. After this script is run, the CMake cache is lost and
-# CMake is not initialised any more!
+# Warning: the test is destructive. It includes various build modes and
+# configurations, and can and will arbitrarily change the current CMake
+# configuration. After this script has been run, the CMake cache will be lost
+# and CMake will no longer be initialised.
 #
-# Assumes gcc and clang (recent enough for using ASan with gcc and MemSan with
-# clang, or valgrind) are available, as well as cmake and a "good" find.
+# The script assumes the presence of gcc and clang (recent enough for using
+# ASan with gcc and MemSan with clang, or valgrind) are available, as well as
+# cmake and a "good" find.
 
-# Abort on errors (and uninitiliased variables)
+# Abort on errors (and uninitialised variables)
 set -eu
 
 if [ -d library -a -d include -a -d tests ]; then :; else
@@ -28,23 +32,16 @@
 
 MEMORY=0
 SHORT=0
+FORCE=0
 
-while [ $# -gt 0 ]; do
-    case "$1" in
-        -m*)
-            MEMORY=${1#-m}
-            ;;
-        -s)
-            SHORT=1
-            ;;
-        *)
-            echo "Unknown argument: '$1'" >&2
-            echo "Use the source, Luke!" >&2
-            exit 1
-            ;;
-    esac
-    shift
-done
+usage()
+{
+    echo "Usage: $0"
+    echo -e "  -h|--help\t\tPrint this help."
+    echo -e "  -m|--memory\t\tAdditional optional memory tests."
+    echo -e "  -s|--short\t\tSubset of tests."
+    echo -e "  -f|--force\t\tForce the tests to overwrite any modified files."
+}
 
 # remove built files as well as the cmake cache/config
 cleanup()
@@ -72,6 +69,50 @@
     echo "******************************************************************"
 }
 
+while [ $# -gt 0 ]; do
+    case "$1" in
+        --memory|-m*)
+            MEMORY=${1#-m}
+            ;;
+        --short|-s)
+            SHORT=1
+            ;;
+        --force|-f)
+            FORCE=1
+            ;;
+        --help|-h|*)
+            usage()
+            exit 1
+            ;;
+    esac
+    shift
+done
+
+if [ $FORCE -eq 1 ]; then
+    rm -rf yotta/module
+    git checkout-index -f -q $CONFIG_H
+    cleanup
+else
+
+    if [ -d yotta/module ]; then
+        echo "Warning - there is an existing yotta module in the directory 'yotta/module'" >&2
+        echo "You can either delete your work and retry, or force the test to overwrite the"
+        echo "test by rerunning the script as: $0 --force"
+        exit 1
+    fi
+
+    if ! git diff-files --quiet include/mbedtls/config.h; then
+        echo $?
+        echo "Warning - the configuration file 'include/mbedtls/config.h' has been edited. " >&2
+        echo "You can either delete or preserve your work, or force the test by rerunning the"
+        echo "script as: $0 --force"
+        exit 1
+    fi
+fi
+
+#
+# Test Suites to be executed
+#
 # The test ordering tries to optimize for the following criteria:
 # 1. Catch possible problems early, by running first tests that run quickly
 #    and/or are more likely to fail than others (eg I use Clang most of the
diff --git a/tests/scripts/basic-build-test.sh b/tests/scripts/basic-build-test.sh
index f1b36c3..d13a8e4 100755
--- a/tests/scripts/basic-build-test.sh
+++ b/tests/scripts/basic-build-test.sh
@@ -38,6 +38,7 @@
 # Step 1 - Make and instrumented build for code coverage
 export CFLAGS=' --coverage -g3 -O0 '
 make clean
+scripts/config.pl full
 make
 
 
diff --git a/tests/scripts/generate_code.pl b/tests/scripts/generate_code.pl
index 5c623f8..5892f7b 100755
--- a/tests/scripts/generate_code.pl
+++ b/tests/scripts/generate_code.pl
@@ -2,6 +2,8 @@
 
 # generate_code.pl
 #
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
 # Copyright (c) 2009-2016, ARM Limited, All Rights Reserved
 #
 # Purpose
@@ -202,7 +204,7 @@
         if( substr($def, 0, 4) eq "int " )
         {
             $param_defs .= "    int param$i;\n";
-            $param_checks .= "    if( verify_int( params[$i], &param$i ) != 0 ) return( 2 );\n";
+            $param_checks .= "    if( verify_int( params[$i], &param$i ) != 0 ) return( DISPATCH_INVALID_TEST_DATA );\n";
             push @dispatch_params, "param$i";
 
             $mapping_regex .= ":([\\d\\w |\\+\\-\\(\\)]+)";
@@ -211,7 +213,7 @@
         elsif( substr($def, 0, 6) eq "char *" )
         {
             $param_defs .= "    char *param$i = params[$i];\n";
-            $param_checks .= "    if( verify_string( &param$i ) != 0 ) return( 2 );\n";
+            $param_checks .= "    if( verify_string( &param$i ) != 0 ) return( DISPATCH_INVALID_TEST_DATA );\n";
             push @dispatch_params, "param$i";
             $mapping_regex .= ":[^:\n]+";
         }
@@ -248,14 +250,14 @@
     if( cnt != $param_count )
     {
         mbedtls_fprintf( stderr, "\\nIncorrect argument count (%d != %d)\\n", cnt, $param_count );
-        return( 2 );
+        return( DISPATCH_INVALID_TEST_DATA );
     }
 
 $param_checks
     test_suite_$function_name( $call_params );
-    return ( 0 );
+    return ( DISPATCH_TEST_SUCCESS );
 $function_post_code
-    return ( 3 );
+    return ( DISPATCH_UNSUPPORTED_SUITE );
 }
 else
 END
@@ -283,9 +285,9 @@
     if( strcmp( str, "$key" ) == 0 )
     {
 #if defined($key)
-        return( 0 );
+        return( DEPENDENCY_SUPPORTED );
 #else
-        return( 1 );
+        return( DEPENDENCY_NOT_SUPPORTED );
 #endif
     }
 END
@@ -298,7 +300,7 @@
     if( strcmp( str, "$key" ) == 0 )
     {
         *value = ( $key );
-        return( 0 );
+        return( KEY_VALUE_MAPPING_FOUND );
     }
 END
 
@@ -315,7 +317,7 @@
 
 $dispatch_code =~ s/^(.+)/    $1/mg;
 
-$test_main =~ s/TEST_FILENAME/$test_case_data/;
+$test_main =~ s/TEST_FILENAME/$test_case_data/g;
 $test_main =~ s/FUNCTION_CODE//;
 $test_main =~ s/DEP_CHECK_CODE/$dep_check_code/;
 $test_main =~ s/DISPATCH_FUNCTION/$dispatch_code/;
diff --git a/tests/scripts/run-test-suites.pl b/tests/scripts/run-test-suites.pl
index fb77e15..58f827c 100755
--- a/tests/scripts/run-test-suites.pl
+++ b/tests/scripts/run-test-suites.pl
@@ -2,6 +2,8 @@
 
 # run-test-suites.pl
 #
+# This file is part of mbed TLS (https://tls.mbed.org)
+#
 # Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
 #
 # Purpose
@@ -66,7 +68,8 @@
         print "(test cases passed:", $suite_cases_passed,
                 " failed:", $suite_cases_failed,
                 " skipped:", $suite_cases_skipped,
-                " of total:", ( $suite_cases_passed + $suite_cases_failed ),
+                " of total:", ($suite_cases_passed + $suite_cases_failed +
+                               $suite_cases_skipped),
                 ")\n"
     }
 
diff --git a/tests/suites/helpers.function b/tests/suites/helpers.function
index c18eed8..2eff043 100644
--- a/tests/suites/helpers.function
+++ b/tests/suites/helpers.function
@@ -32,9 +32,18 @@
 
 
 /*----------------------------------------------------------------------------*/
-/* Global variables */
+/* Constants */
 
-static int test_errors = 0;
+#define DEPENDENCY_SUPPORTED        0
+#define DEPENDENCY_NOT_SUPPORTED    1
+
+#define KEY_VALUE_MAPPING_FOUND     0
+#define KEY_VALUE_MAPPING_NOT_FOUND -1
+
+#define DISPATCH_TEST_SUCCESS       0
+#define DISPATCH_TEST_FN_NOT_FOUND  1
+#define DISPATCH_INVALID_TEST_DATA  2
+#define DISPATCH_UNSUPPORTED_SUITE  3
 
 
 /*----------------------------------------------------------------------------*/
@@ -81,6 +90,12 @@
 
 
 /*----------------------------------------------------------------------------*/
+/* Global variables */
+
+static int test_errors = 0;
+
+
+/*----------------------------------------------------------------------------*/
 /* Helper Functions */
 
 static int unhexify( unsigned char *obuf, const char *ibuf )
diff --git a/tests/suites/main_test.function b/tests/suites/main_test.function
index 7ec69b4..525df5b 100644
--- a/tests/suites/main_test.function
+++ b/tests/suites/main_test.function
@@ -60,7 +60,7 @@
 MAPPING_CODE
 
     mbedtls_printf( "Expected integer for parameter and got: %s\n", str );
-    return( -1 );
+    return( KEY_VALUE_MAPPING_NOT_FOUND );
 }
 
 
@@ -81,7 +81,7 @@
 
 DEP_CHECK_CODE
 
-    return( 1 );
+    return( DEPENDENCY_NOT_SUPPORTED );
 }
 
 int dispatch_test(int cnt, char *params[50])
@@ -91,14 +91,18 @@
     ((void) params);
 
 #if defined(TEST_SUITE_ACTIVE)
+    ret = DISPATCH_TEST_SUCCESS;
+
 DISPATCH_FUNCTION
     {
-        mbedtls_fprintf( stdout, "FAILED\nSkipping unknown test function '%s'\n", params[0] );
+        mbedtls_fprintf( stdout,
+                         "FAILED\nSkipping unknown test function '%s'\n",
+                         params[0] );
         fflush( stdout );
-        return( 1 );
+        ret = DISPATCH_TEST_FN_NOT_FOUND;
     }
 #else
-    return( 3 );
+    ret = DISPATCH_UNSUPPORTED_SUITE;
 #endif
     return( ret );
 }
@@ -107,6 +111,19 @@
 /*----------------------------------------------------------------------------*/
 /* Main Test code */
 
+#define USAGE \
+    "Usage: %s [OPTIONS] files...\n\n" \
+    "   Command line arguments:\n" \
+    "     files...          One or more test data file. If no file is specified\n" \
+    "                       the followimg default test case is used:\n" \
+    "                           %s\n\n" \
+    "   Options:\n" \
+    "     -v | --verbose    Display full information about each test\n" \
+    "     -h | --help       Display this information\n\n", \
+    argv[0], \
+    "TEST_FILENAME"
+
+
 int get_line( FILE *f, char *buf, size_t len )
 {
     char *ret;
@@ -216,11 +233,18 @@
 
 int main(int argc, const char *argv[])
 {
-    int testfile_index, testfile_count, ret, i, cnt;
-    int total_errors = 0, total_tests = 0, total_skipped = 0;
+    /* Local Configurations and options */
     const char *default_filename = "TEST_FILENAME";
     const char *test_filename = NULL;
     const char **test_files = NULL;
+    int testfile_count = 0;
+    int option_verbose = 0;
+
+    /* Other Local variables */
+    int arg_index = 1;
+    const char *next_arg;
+    int testfile_index, ret, i, cnt;
+    int total_errors = 0, total_tests = 0, total_skipped = 0;
     FILE *file;
     char buf[5000];
     char *params[50];
@@ -253,17 +277,41 @@
         return( 0 );
     }
 
-    if ( argc <= 1 )
+    while( arg_index < argc)
+    {
+        next_arg = argv[ arg_index ];
+
+        if( strcmp(next_arg, "--verbose" ) == 0 ||
+                 strcmp(next_arg, "-v" ) == 0 )
+        {
+            option_verbose = 1;
+        }
+        else if( strcmp(next_arg, "--help" ) == 0 ||
+                 strcmp(next_arg, "-h" ) == 0 )
+        {
+            mbedtls_fprintf( stdout, USAGE );
+            mbedtls_exit( EXIT_SUCCESS );
+        }
+        else
+        {
+            /* Not an option, therefore treat all further arguments as the file
+             * list.
+             */
+            test_files = &argv[ arg_index ];
+            testfile_count = argc - arg_index;
+        }
+
+        arg_index++;
+    }
+
+    /* If no files were specified, assume a default */
+    if ( test_files == NULL || testfile_count == 0 )
     {
         test_files = &default_filename;
         testfile_count = 1;
     }
-    else
-    {
-        test_files = &argv[1];
-        testfile_count = argc - 1;
-    }
 
+    /* Now begin to execute the tests in the testfiles */
     for ( testfile_index = 0;
           testfile_index < testfile_count;
           testfile_index++ )
@@ -280,7 +328,8 @@
 
         while( !feof( file ) )
         {
-            int skip = 0;
+            int unmet_dep_count = 0;
+            char *unmet_dependencies[20];
 
             if( ( ret = get_line( file, buf, sizeof(buf) ) ) != 0 )
                 break;
@@ -300,32 +349,61 @@
             if( strcmp( params[0], "depends_on" ) == 0 )
             {
                 for( i = 1; i < cnt; i++ )
-                    if( dep_check( params[i] ) != 0 )
-                        skip = 1;
+                {
+                    if( dep_check( params[i] ) != DEPENDENCY_SUPPORTED )
+                    {
+                        unmet_dependencies[ i-1 ] = strdup(params[i]);
+                        if(  unmet_dependencies[ i-1 ] == NULL )
+                        {
+                            mbedtls_printf("FATAL: Out of memory\n");
+                            mbedtls_exit( MBEDTLS_PLATFORM_STD_EXIT_FAILURE );
+                        }
+                        unmet_dep_count++;
+                    }
+                }
 
                 if( ( ret = get_line( file, buf, sizeof(buf) ) ) != 0 )
                     break;
                 cnt = parse_arguments( buf, strlen(buf), params );
             }
-
-            if( skip == 0 )
+ 
+            // If there are no unmet dependencies execute the test
+            if( unmet_dep_count == 0 )
             {
                 test_errors = 0;
                 ret = dispatch_test( cnt, params );
             }
 
-            if( skip == 1 || ret == 3 )
+            if( unmet_dep_count > 0 || ret == DISPATCH_UNSUPPORTED_SUITE )
             {
                 total_skipped++;
                 mbedtls_fprintf( stdout, "----\n" );
+
+                if( 1 == option_verbose && ret == DISPATCH_UNSUPPORTED_SUITE )
+                {
+                    mbedtls_fprintf( stdout, "   Test Suite not enabled" );
+                }
+
+                if( 1 == option_verbose && unmet_dep_count > 0 )
+                {
+                    mbedtls_fprintf( stdout, "   Unmet dependencies: " );
+                    while( unmet_dep_count > 0)
+                    {
+                        mbedtls_fprintf(stdout, "%s  ",
+                                        unmet_dependencies[unmet_dep_count - 1]);
+                        free(unmet_dependencies[unmet_dep_count - 1]);
+                        unmet_dep_count--;
+                    }
+                    mbedtls_fprintf( stdout, "\n" );
+                }
                 fflush( stdout );
             }
-            else if( ret == 0 && test_errors == 0 )
+            else if( ret == DISPATCH_TEST_SUCCESS && test_errors == 0 )
             {
                 mbedtls_fprintf( stdout, "PASS\n" );
                 fflush( stdout );
             }
-            else if( ret == 2 )
+            else if( ret == DISPATCH_INVALID_TEST_DATA )
             {
                 mbedtls_fprintf( stderr, "FAILED: FATAL PARSE ERROR\n" );
                 fclose(file);
diff --git a/tests/suites/test_suite_rsa.data b/tests/suites/test_suite_rsa.data
index c43d6ae..d522332 100644
--- a/tests/suites/test_suite_rsa.data
+++ b/tests/suites/test_suite_rsa.data
@@ -345,7 +345,7 @@
 RSA Public (Data larger than N)
 mbedtls_rsa_public:"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":2048:16:"b38ac65c8141f7f5c96e14470e851936a67bf94cc6821a39ac12c05f7c0b06d9e6ddba2224703b02e25f31452f9c4a8417b62675fdc6df46b94813bc7b9769a892c482b830bfe0ad42e46668ace68903617faf6681f4babf1cc8e4b0420d3c7f61dc45434c6b54e2c3ee0fc07908509d79c9826e673bf8363255adb0add2401039a7bcd1b4ecf0fbe6ec8369d2da486eec59559dd1d54c9b24190965eafbdab203b35255765261cd0909acf93c3b8b8428cbb448de4715d1b813d0c94829c229543d391ce0adab5351f97a3810c1f73d7b1458b97daed4209c50e16d064d2d5bfda8c23893d755222793146d0a78c3d64f35549141486c3b0961a7b4c1a2034f":16:"3":"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":MBEDTLS_ERR_RSA_PUBLIC_FAILED + MBEDTLS_ERR_MPI_BAD_INPUT_DATA
 
-RSA Generate Key
+RSA Generate Key - 128bit key
 mbedtls_rsa_gen_key:128:3:0
 
 RSA Generate Key (Number of bits too small)
@@ -354,9 +354,15 @@
 RSA Generate Key (Exponent too small)
 mbedtls_rsa_gen_key:128:2:MBEDTLS_ERR_RSA_BAD_INPUT_DATA
 
-RSA Generate Key
+RSA Generate Key - 1024 bit key
 mbedtls_rsa_gen_key:1024:3:0
 
+RSA Generate Key - 2048 bit key
+mbedtls_rsa_gen_key:2048:3:0
+
+RSA Generate Key - 1025 bit key
+mbedtls_rsa_gen_key:1025:3:0
+
 RSA PKCS1 Encrypt Bad RNG
 depends_on:MBEDTLS_PKCS1_V15
 rsa_pkcs1_encrypt_bad_rng:"4E636AF98E40F3ADCFCCB698F4E80B9F":MBEDTLS_RSA_PKCS_V15:2048:16:"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":16:"3":"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":MBEDTLS_ERR_RSA_RNG_FAILED
diff --git a/yotta/data/entropy_hardware_poll.c b/yotta/data/entropy_hardware_poll.c
index 1924302..3a61e22 100644
--- a/yotta/data/entropy_hardware_poll.c
+++ b/yotta/data/entropy_hardware_poll.c
@@ -1,5 +1,5 @@
 /*
- *  Temporary "entropy" collector for Cortex-M4
+ *  Hardware entropy collector for the K64F, using Freescale's RNGA
  *
  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
@@ -20,46 +20,69 @@
  */
 
 /*
- * WARNING: this is a temporary hack!
- * 1. Currently does not provide strong entropy, should be replaced to use the
- * on-board hardware RNG (see IOTSSL-303)
- * 2. This should be in a separete yotta module which would be a target
+ * WARNING: this is temporary!
+ * This should be in a separate yotta module which would be a target
  * dependency of mbedtls (see IOTSSL-313)
  */
 
-#if defined(TARGET_LIKE_CORTEX_M4)
+#if defined(TARGET_LIKE_K64F)
 
-#include "MK64F12.h"
-#include "core_cm4.h"
-#include <string.h>
+/*
+ * Reference: "K64 Sub-Family Reference Manual, Rev. 2", chapter 34
+ */
 
-unsigned long hardclock( void )
+#include "fsl_clock_manager.h"
+
+/*
+ * Get one byte of entropy from the RNG, assuming it is up and running.
+ * As recommended (34.1.1), get only one bit of each output.
+ */
+static void rng_get_byte( unsigned char *byte )
 {
-    static int dwt_started = 0;
+    size_t bit;
 
-    if( dwt_started == 0 )
+    /* 34.5 Steps 3-4-5: poll SR and read from OR when ready */
+    for( bit = 0; bit < 8; bit++ )
     {
-        CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
-        DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;
+        while( ( RNG->SR & RNG_SR_OREG_LVL_MASK ) == 0 );
+        *byte |= ( RNG->OR & 1 ) << bit;
     }
-
-    return( DWT->CYCCNT );
 }
 
+/*
+ * Get len bytes of entropy from the hardware RNG.
+ */
 int mbedtls_hardware_poll( void *data,
                     unsigned char *output, size_t len, size_t *olen )
 {
-    unsigned long timer = hardclock();
+    size_t i;
+    int ret;
     ((void) data);
-    *olen = 0;
 
-    if( len < sizeof(unsigned long) )
-        return( 0 );
+    CLOCK_SYS_EnableRngaClock( 0 );
 
-    memcpy( output, &timer, sizeof(unsigned long) );
-    *olen = sizeof(unsigned long);
+    /* Set "Interrupt Mask", "High Assurance" and "Go",
+     * unset "Clear interrupt" and "Sleep" */
+    RNG->CR = RNG_CR_INTM_MASK | RNG_CR_HA_MASK | RNG_CR_GO_MASK;
 
-    return( 0 );
+    for( i = 0; i < len; i++ )
+        rng_get_byte( output + i );
+
+    /* Just be extra sure that we didn't do it wrong */
+    if( ( RNG->SR & RNG_SR_SECV_MASK ) != 0 )
+    {
+        ret = -1;
+        goto cleanup;
+    }
+
+    *olen = len;
+    ret = 0;
+
+cleanup:
+    /* Disable clock to save power - assume we're the only users of RNG */
+    CLOCK_SYS_DisableRngaClock( 0 );
+
+    return( ret );
 }
 
 #endif
diff --git a/yotta/data/target_config.h b/yotta/data/target_config.h
index df1a208..f350ce3 100644
--- a/yotta/data/target_config.h
+++ b/yotta/data/target_config.h
@@ -26,10 +26,10 @@
 #endif
 
 /*
- * WARNING: this is a temporary hack!
- * 2. This should be in a separete yotta module which would be a target
+ * WARNING: this is temporary!
+ * This should be in a separate yotta module which would be a target
  * dependency of mbedtls (see IOTSSL-313)
  */
-#if defined(TARGET_LIKE_CORTEX_M4)
+#if defined(TARGET_LIKE_K64F)
 #define MBEDTLS_ENTROPY_HARDWARE_ALT
 #endif