diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index d31555d..b36e27b 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -3,7 +3,7 @@
  *
  * \brief Consistency checks for configuration options
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -357,6 +357,38 @@
 #error "MBEDTLS_PLATFORM_STD_SNPRINTF defined, but not all prerequisites"
 #endif
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED) &&\
+    ( !defined(MBEDTLS_PLATFORM_C) || !defined(MBEDTLS_ENTROPY_C) )
+#error "MBEDTLS_ENTROPY_NV_SEED defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_NV_SEED_ALT) &&\
+    !defined(MBEDTLS_ENTROPY_NV_SEED)
+#error "MBEDTLS_PLATFORM_NV_SEED_ALT defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ) &&\
+    !defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
+#error "MBEDTLS_PLATFORM_STD_NV_SEED_READ defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE) &&\
+    !defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
+#error "MBEDTLS_PLATFORM_STD_NV_SEED_WRITE defined, but not all prerequisites"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_NV_SEED_READ_MACRO) &&\
+    ( defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ) ||\
+      defined(MBEDTLS_PLATFORM_NV_SEED_ALT) )
+#error "MBEDTLS_PLATFORM_NV_SEED_READ_MACRO and MBEDTLS_PLATFORM_STD_NV_SEED_READ cannot be defined simultaneously"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO) &&\
+    ( defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE) ||\
+      defined(MBEDTLS_PLATFORM_NV_SEED_ALT) )
+#error "MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO and MBEDTLS_PLATFORM_STD_NV_SEED_WRITE cannot be defined simultaneously"
+#endif
+
 #if defined(MBEDTLS_RSA_C) && ( !defined(MBEDTLS_BIGNUM_C) ||         \
     !defined(MBEDTLS_OID_C) )
 #error "MBEDTLS_RSA_C defined, but not all prerequisites"
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 0a8c056..8b6de1b 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -156,6 +156,7 @@
 //#define MBEDTLS_PLATFORM_FPRINTF_ALT
 //#define MBEDTLS_PLATFORM_PRINTF_ALT
 //#define MBEDTLS_PLATFORM_SNPRINTF_ALT
+//#define MBEDTLS_PLATFORM_NV_SEED_ALT
 
 /**
  * \def MBEDTLS_DEPRECATED_WARNING
@@ -800,6 +801,34 @@
 //#define MBEDTLS_ENTROPY_FORCE_SHA256
 
 /**
+ * \def MBEDTLS_ENTROPY_NV_SEED
+ *
+ * Enable the non-volatile (NV) seed file-based entropy source.
+ * (Also enables the NV seed read/write functions in the platform layer)
+ *
+ * This is crucial (if not required) on systems that do not have a
+ * cryptographic entropy source (in hardware or kernel) available.
+ *
+ * Requires: MBEDTLS_ENTROPY_C, MBEDTLS_PLATFORM_C
+ *
+ * \note The read/write functions that are used by the entropy source are
+ *       determined in the platform layer, and can be modified at runtime and/or
+ *       compile-time depending on the flags (MBEDTLS_PLATFORM_NV_SEED_*) used.
+ *
+ * \note If you use the default implementation functions that read a seedfile
+ *       with regular fopen(), please make sure you make a seedfile with the
+ *       proper name (defined in MBEDTLS_PLATFORM_STD_NV_SEED_FILE) and at
+ *       least MBEDTLS_ENTROPY_BLOCK_SIZE bytes in size that can be read from
+ *       and written to or you will get an entropy source error! The default
+ *       implementation will only use the first MBEDTLS_ENTROPY_BLOCK_SIZE
+ *       bytes from the file.
+ *
+ * \note The entropy collector will write to the seed file before entropy is
+ *       given to an external source, to update it.
+ */
+//#define MBEDTLS_ENTROPY_NV_SEED
+
+/**
  * \def MBEDTLS_MEMORY_DEBUG
  *
  * Enable debugging of buffer allocator memory issues. Automatically prints
@@ -2473,6 +2502,9 @@
 //#define MBEDTLS_PLATFORM_STD_SNPRINTF    snprintf /**< Default snprintf to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_SUCCESS       0 /**< Default exit value to use, can be undefined */
 //#define MBEDTLS_PLATFORM_STD_EXIT_FAILURE       1 /**< Default exit value to use, can be undefined */
+//#define MBEDTLS_PLATFORM_STD_NV_SEED_READ   mbedtls_platform_std_nv_seed_read /**< Default nv_seed_read function to use, can be undefined */
+//#define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE  mbedtls_platform_std_nv_seed_write /**< Default nv_seed_write function to use, can be undefined */
+//#define MBEDTLS_PLATFORM_STD_NV_SEED_FILE  "seedfile" /**< Seed file to read/write with default implementation */
 
 /* To Use Function Macros MBEDTLS_PLATFORM_C must be enabled */
 /* MBEDTLS_PLATFORM_XXX_MACRO and MBEDTLS_PLATFORM_XXX_ALT cannot both be defined */
@@ -2485,6 +2517,8 @@
 //#define MBEDTLS_PLATFORM_PRINTF_MACRO        printf /**< Default printf macro to use, can be undefined */
 /* Note: your snprintf must correclty zero-terminate the buffer! */
 //#define MBEDTLS_PLATFORM_SNPRINTF_MACRO    snprintf /**< Default snprintf macro to use, can be undefined */
+//#define MBEDTLS_PLATFORM_NV_SEED_READ_MACRO   mbedtls_platform_std_nv_seed_read /**< Default nv_seed_read function to use, can be undefined */
+//#define MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO  mbedtls_platform_std_nv_seed_write /**< Default nv_seed_write function to use, can be undefined */
 
 /* SSL Cache options */
 //#define MBEDTLS_SSL_CACHE_DEFAULT_TIMEOUT       86400 /**< 1 day  */
diff --git a/include/mbedtls/entropy.h b/include/mbedtls/entropy.h
index 00de9a6..fed0494 100644
--- a/include/mbedtls/entropy.h
+++ b/include/mbedtls/entropy.h
@@ -3,7 +3,7 @@
  *
  * \brief Entropy accumulator implementation
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -134,6 +134,9 @@
 #if defined(MBEDTLS_THREADING_C)
     mbedtls_threading_mutex_t mutex;    /*!< mutex                  */
 #endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+    int initial_entropy_run;
+#endif
 }
 mbedtls_entropy_context;
 
@@ -208,6 +211,18 @@
 int mbedtls_entropy_update_manual( mbedtls_entropy_context *ctx,
                            const unsigned char *data, size_t len );
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/**
+ * \brief           Trigger an update of the seed file in NV by using the
+ *                  current entropy pool.
+ *
+ * \param ctx       Entropy context
+ *
+ * \return          0 if successful
+ */
+int mbedtls_entropy_update_nv_seed( mbedtls_entropy_context *ctx );
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #if defined(MBEDTLS_FS_IO)
 /**
  * \brief               Write a seed file
diff --git a/include/mbedtls/entropy_poll.h b/include/mbedtls/entropy_poll.h
index dc11911..123f09c 100644
--- a/include/mbedtls/entropy_poll.h
+++ b/include/mbedtls/entropy_poll.h
@@ -3,7 +3,7 @@
  *
  * \brief Platform-specific and custom entropy polling functions
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -82,6 +82,16 @@
                            unsigned char *output, size_t len, size_t *olen );
 #endif
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/**
+ * \brief           Entropy poll callback for a non-volatile seed file
+ *
+ * \note            This must accept NULL as its first argument.
+ */
+int mbedtls_nv_seed_poll( void *data,
+                          unsigned char *output, size_t len, size_t *olen );
+#endif
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/mbedtls/platform.h b/include/mbedtls/platform.h
index 039cb58..5fa01b5 100644
--- a/include/mbedtls/platform.h
+++ b/include/mbedtls/platform.h
@@ -3,7 +3,7 @@
  *
  * \brief mbed TLS Platform abstraction layer
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -76,12 +76,24 @@
 #if !defined(MBEDTLS_PLATFORM_STD_EXIT_FAILURE)
 #define MBEDTLS_PLATFORM_STD_EXIT_FAILURE  EXIT_FAILURE /**< Default exit value to use */
 #endif
+#if defined(MBEDTLS_FS_IO)
+#if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
+#define MBEDTLS_PLATFORM_STD_NV_SEED_READ   mbedtls_platform_std_nv_seed_read
+#endif
+#if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
+#define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE  mbedtls_platform_std_nv_seed_write
+#endif
+#if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_FILE)
+#define MBEDTLS_PLATFORM_STD_NV_SEED_FILE   "seedfile"
+#endif
+#endif /* MBEDTLS_FS_IO */
 #else /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
 #if defined(MBEDTLS_PLATFORM_STD_MEM_HDR)
 #include MBEDTLS_PLATFORM_STD_MEM_HDR
 #endif
 #endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
 
+
 /* \} name SECTION: Module settings */
 
 /*
@@ -262,6 +274,47 @@
 #endif /* MBEDTLS_PLATFORM_TIME_MACRO */
 #endif /* MBEDTLS_PLATFORM_TIME_ALT */
 
+/*
+ * The function pointers for reading from and writing a seed file to
+ * Non-Volatile storage (NV) in a platform-independent way
+ *
+ * Only enabled when the NV seed entropy source is enabled
+ */
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+#if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
+/* Internal standard platform definitions */
+int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len );
+int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len );
+#endif
+
+#if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
+extern int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len );
+extern int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len );
+
+/**
+ * \brief   Set your own seed file writing/reading functions
+ *
+ * \param   nv_seed_read_func   the seed reading function implementation
+ * \param   nv_seed_write_func  the seed writing function implementation
+ *
+ * \return              0
+ */
+int mbedtls_platform_set_nv_seed(
+            int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
+            int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len )
+            );
+#else
+#if defined(MBEDTLS_PLATFORM_NV_SEED_READ_MACRO) && \
+    defined(MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO)
+#define mbedtls_nv_seed_read    MBEDTLS_PLATFORM_NV_SEED_READ_MACRO
+#define mbedtls_nv_seed_write   MBEDTLS_PLATFORM_NV_SEED_WRITE_MACRO
+#else
+#define mbedtls_nv_seed_read    mbedtls_platform_std_nv_seed_read
+#define mbedtls_nv_seed_write   mbedtls_platform_std_nv_seed_write
+#endif
+#endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/library/entropy.c b/library/entropy.c
index cdbd35c..dc2a00c 100644
--- a/library/entropy.c
+++ b/library/entropy.c
@@ -1,7 +1,7 @@
 /*
  *  Entropy accumulator implementation
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -94,6 +94,11 @@
                                 MBEDTLS_ENTROPY_MIN_HARDWARE,
                                 MBEDTLS_ENTROPY_SOURCE_STRONG );
 #endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+    mbedtls_entropy_add_source( ctx, mbedtls_nv_seed_poll, NULL,
+                                MBEDTLS_ENTROPY_BLOCK_SIZE,
+                                MBEDTLS_ENTROPY_SOURCE_STRONG );
+#endif
 #endif /* MBEDTLS_NO_DEFAULT_ENTROPY_SOURCES */
 }
 
@@ -272,6 +277,18 @@
     if( len > MBEDTLS_ENTROPY_BLOCK_SIZE )
         return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+    /* Update the NV entropy seed before generating any entropy for outside
+     * use.
+     */
+    if( ctx->initial_entropy_run == 0 )
+    {
+        ctx->initial_entropy_run = 1;
+        if( ( ret = mbedtls_entropy_update_nv_seed( ctx ) ) != 0 )
+            return( ret );
+    }
+#endif
+
 #if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )
         return( ret );
@@ -346,6 +363,27 @@
     return( ret );
 }
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+int mbedtls_entropy_update_nv_seed( mbedtls_entropy_context *ctx )
+{
+    int ret = MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR;
+    unsigned char buf[ MBEDTLS_ENTROPY_MAX_SEED_SIZE ];
+
+    /* Read new seed  and write it to NV */
+    if( ( ret = mbedtls_entropy_func( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) ) != 0 )
+        return( ret );
+
+    if( mbedtls_nv_seed_write( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
+        return( MBEDTLS_ERR_ENTROPY_FILE_IO_ERROR );
+
+    /* Manually update the remaining stream with a separator value to diverge */
+    memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    mbedtls_entropy_update_manual( ctx, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    return( 0 );
+}
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #if defined(MBEDTLS_FS_IO)
 int mbedtls_entropy_write_seed_file( mbedtls_entropy_context *ctx, const char *path )
 {
diff --git a/library/entropy_poll.c b/library/entropy_poll.c
index e2f45c7..fcb7d8b 100644
--- a/library/entropy_poll.c
+++ b/library/entropy_poll.c
@@ -1,7 +1,7 @@
 /*
  *  Platform-specific and custom entropy polling functions
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -37,6 +37,9 @@
 #if defined(MBEDTLS_HAVEGE_C)
 #include "mbedtls/havege.h"
 #endif
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+#include "mbedtls/platform.h"
+#endif
 
 #if !defined(MBEDTLS_NO_PLATFORM_ENTROPY)
 
@@ -222,4 +225,27 @@
 }
 #endif /* MBEDTLS_HAVEGE_C */
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+int mbedtls_nv_seed_poll( void *data,
+                          unsigned char *output, size_t len, size_t *olen )
+{
+    unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    size_t use_len = MBEDTLS_ENTROPY_BLOCK_SIZE;
+    ((void) data);
+
+    memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    if( mbedtls_nv_seed_read( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) < 0 )
+      return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED );
+
+    if( len < use_len )
+      use_len = len;
+
+    memcpy( output, buf, use_len );
+    *olen = use_len;
+
+    return( 0 );
+}
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #endif /* MBEDTLS_ENTROPY_C */
diff --git a/library/platform.c b/library/platform.c
index 89a2bd6..68ca45d 100644
--- a/library/platform.c
+++ b/library/platform.c
@@ -1,7 +1,7 @@
 /*
  *  Platform abstraction layer
  *
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright (C) 2006-2016, ARM Limited, All Rights Reserved
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -213,4 +213,91 @@
 }
 #endif /* MBEDTLS_PLATFORM_TIME_ALT */
 
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+#if !defined(MBEDTLS_PLATFORM_NO_STD_FUNCTIONS) && defined(MBEDTLS_FS_IO)
+/* Default implementations for the platform independent seed functions use
+ * standard libc file functions to read from and write to a pre-defined filename
+ */
+int mbedtls_platform_std_nv_seed_read( unsigned char *buf, size_t buf_len )
+{
+    FILE *file;
+    size_t n;
+
+    if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
+        return -1;
+
+    if( ( n = fread( buf, 1, buf_len, file ) ) != buf_len )
+    {
+        fclose( file );
+        return -1;
+    }
+
+    fclose( file );
+    return( n );
+}
+
+int mbedtls_platform_std_nv_seed_write( unsigned char *buf, size_t buf_len )
+{
+    FILE *file;
+    size_t n;
+
+    if( ( file = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
+        return -1;
+
+    if( ( n = fwrite( buf, 1, buf_len, file ) ) != buf_len )
+    {
+        fclose( file );
+        return -1;
+    }
+
+    fclose( file );
+    return( n );
+}
+#endif /* MBEDTLS_PLATFORM_NO_STD_FUNCTIONS */
+
+#if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
+#if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_READ)
+/*
+ * Make dummy function to prevent NULL pointer dereferences
+ */
+static int platform_nv_seed_read_uninit( unsigned char *buf, size_t buf_len )
+{
+    ((void) buf);
+    ((void) buf_len);
+    return( -1 );
+}
+
+#define MBEDTLS_PLATFORM_STD_NV_SEED_READ   platform_nv_seed_read_uninit
+#endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_READ */
+
+#if !defined(MBEDTLS_PLATFORM_STD_NV_SEED_WRITE)
+/*
+ * Make dummy function to prevent NULL pointer dereferences
+ */
+static int platform_nv_seed_write_uninit( unsigned char *buf, size_t buf_len )
+{
+    ((void) buf);
+    ((void) buf_len);
+    return( -1 );
+}
+
+#define MBEDTLS_PLATFORM_STD_NV_SEED_WRITE   platform_nv_seed_write_uninit
+#endif /* !MBEDTLS_PLATFORM_STD_NV_SEED_WRITE */
+
+int (*mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) =
+            MBEDTLS_PLATFORM_STD_NV_SEED_READ;
+int (*mbedtls_nv_seed_write)( unsigned char *buf, size_t buf_len ) =
+            MBEDTLS_PLATFORM_STD_NV_SEED_WRITE;
+
+int mbedtls_platform_set_nv_seed(
+        int (*nv_seed_read_func)( unsigned char *buf, size_t buf_len ),
+        int (*nv_seed_write_func)( unsigned char *buf, size_t buf_len ) )
+{
+    mbedtls_nv_seed_read = nv_seed_read_func;
+    mbedtls_nv_seed_write = nv_seed_write_func;
+    return( 0 );
+}
+#endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
+
 #endif /* MBEDTLS_PLATFORM_C */
diff --git a/library/version_features.c b/library/version_features.c
index b852ca8..a9b1c53 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -66,6 +66,9 @@
 #if defined(MBEDTLS_PLATFORM_SNPRINTF_ALT)
     "MBEDTLS_PLATFORM_SNPRINTF_ALT",
 #endif /* MBEDTLS_PLATFORM_SNPRINTF_ALT */
+#if defined(MBEDTLS_PLATFORM_NV_SEED_ALT)
+    "MBEDTLS_PLATFORM_NV_SEED_ALT",
+#endif /* MBEDTLS_PLATFORM_NV_SEED_ALT */
 #if defined(MBEDTLS_DEPRECATED_WARNING)
     "MBEDTLS_DEPRECATED_WARNING",
 #endif /* MBEDTLS_DEPRECATED_WARNING */
@@ -291,6 +294,9 @@
 #if defined(MBEDTLS_ENTROPY_FORCE_SHA256)
     "MBEDTLS_ENTROPY_FORCE_SHA256",
 #endif /* MBEDTLS_ENTROPY_FORCE_SHA256 */
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+    "MBEDTLS_ENTROPY_NV_SEED",
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
 #if defined(MBEDTLS_MEMORY_DEBUG)
     "MBEDTLS_MEMORY_DEBUG",
 #endif /* MBEDTLS_MEMORY_DEBUG */
diff --git a/tests/suites/test_suite_entropy.data b/tests/suites/test_suite_entropy.data
index 833eef5..5ca99f8 100644
--- a/tests/suites/test_suite_entropy.data
+++ b/tests/suites/test_suite_entropy.data
@@ -1,3 +1,6 @@
+Create NV seed_file
+nv_seed_file_create:
+
 Entropy write/update seed file
 entropy_seed_file:"data_files/entropy_seed":0
 
@@ -37,5 +40,17 @@
 Entropy thershold #4
 entropy_threshold:1024:1:MBEDTLS_ERR_ENTROPY_SOURCE_FAILED
 
+Check NV seed standard IO
+entropy_nv_seed_std_io:
+
+Check NV seed manually #1
+entropy_nv_seed:"00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF00112233445566778899AABBCCDDEEFF"
+
+Check NV seed manually #2
+entropy_nv_seed:"00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"
+
+Check NV seed manually #3
+entropy_nv_seed:"ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"
+
 Entropy self test
 entropy_selftest:
diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function
index 3b739cc..d1ef94b 100644
--- a/tests/suites/test_suite_entropy.function
+++ b/tests/suites/test_suite_entropy.function
@@ -1,5 +1,6 @@
 /* BEGIN_HEADER */
 #include "mbedtls/entropy.h"
+#include "mbedtls/entropy_poll.h"
 
 /*
  * Number of calls made to entropy_dummy_source()
@@ -33,6 +34,88 @@
 
     return( 0 );
 }
+
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+/*
+ * Ability to clear entropy sources to allow testing with just predefined
+ * entropy sources. This function or tests depending on it might break if there
+ * are internal changes to how entropy sources are registered.
+ *
+ * To be called immediately after mbedtls_entropy_init().
+ *
+ * Just resetting the counter. New sources will overwrite existing ones.
+ * This might break memory checks in the future if sources need 'free-ing' then
+ * as well.
+ */
+static void entropy_clear_sources( mbedtls_entropy_context *ctx )
+{
+    ctx->source_count = 0;
+}
+
+/*
+ * NV seed read/write functions that use a buffer instead of a file
+ */
+static unsigned char buffer_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
+
+static int buffer_nv_seed_read( unsigned char *buf, size_t buf_len )
+{
+    if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    memcpy( buf, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    return( 0 );
+}
+
+static int buffer_nv_seed_write( unsigned char *buf, size_t buf_len )
+{
+    if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    memcpy( buffer_seed, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    return( 0 );
+}
+
+/*
+ * NV seed read/write helpers that fill the base seedfile
+ */
+static int write_nv_seed( unsigned char *buf, size_t buf_len )
+{
+    FILE *f;
+
+    if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    if( ( f = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "w" ) ) == NULL )
+        return( -1 );
+
+    if( fwrite( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) !=
+                    MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    fclose( f );
+
+    return( 0 );
+}
+
+static int read_nv_seed( unsigned char *buf, size_t buf_len )
+{
+    FILE *f;
+
+    if( buf_len != MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    if( ( f = fopen( MBEDTLS_PLATFORM_STD_NV_SEED_FILE, "rb" ) ) == NULL )
+        return( -1 );
+
+    if( fread( buf, 1, MBEDTLS_ENTROPY_BLOCK_SIZE, f ) !=
+                    MBEDTLS_ENTROPY_BLOCK_SIZE )
+        return( -1 );
+
+    fclose( f );
+
+    return( 0 );
+}
+#endif /* MBEDTLS_ENTROPY_NV_SEED */
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -160,6 +243,10 @@
     if( result >= 0 )
     {
         TEST_ASSERT( ret == 0 );
+#if defined(MBEDTLS_ENTROPY_NV_SEED)
+        // Two times as much calls due to the NV seed update
+        result *= 2;
+#endif
         TEST_ASSERT( entropy_dummy_calls == (size_t) result );
     }
     else
@@ -172,6 +259,124 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO */
+void nv_seed_file_create()
+{
+    unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
+
+    memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    TEST_ASSERT( write_nv_seed( buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_FS_IO:MBEDTLS_PLATFORM_NV_SEED_ALT */
+void entropy_nv_seed_std_io()
+{
+    unsigned char io_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
+
+    memset( io_seed, 1, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    mbedtls_platform_set_nv_seed( mbedtls_platform_std_nv_seed_read,
+                                  mbedtls_platform_std_nv_seed_write );
+
+    /* Check if platform NV read and write manipulate the same data */
+    TEST_ASSERT( write_nv_seed( io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+    TEST_ASSERT( mbedtls_nv_seed_read( check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) ==
+                    MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    TEST_ASSERT( memcmp( io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+
+    memset( check_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    /* Check if platform NV write and raw read manipulate the same data */
+    TEST_ASSERT( mbedtls_nv_seed_write( io_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) ==
+                    MBEDTLS_ENTROPY_BLOCK_SIZE );
+    TEST_ASSERT( read_nv_seed( check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+
+    TEST_ASSERT( memcmp( io_seed, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+}
+/* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT:MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */
+void entropy_nv_seed( char *read_seed_str )
+{
+    mbedtls_sha512_context accumulator;
+    mbedtls_entropy_context ctx;
+
+    unsigned char header[2];
+    unsigned char entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char buf[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char empty[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char read_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char check_seed[MBEDTLS_ENTROPY_BLOCK_SIZE];
+    unsigned char check_entropy[MBEDTLS_ENTROPY_BLOCK_SIZE];
+
+    memset( entropy, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( buffer_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    memset( check_entropy, 3, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    // Set the initial NV seed to read
+    unhexify( read_seed, read_seed_str );
+    memcpy( buffer_seed, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    // Make sure we read/write NV seed from our buffers
+    mbedtls_platform_set_nv_seed( buffer_nv_seed_read, buffer_nv_seed_write );
+
+    mbedtls_entropy_init( &ctx );
+    entropy_clear_sources( &ctx );
+
+    TEST_ASSERT( mbedtls_entropy_add_source( &ctx, mbedtls_nv_seed_poll, NULL,
+                                             MBEDTLS_ENTROPY_BLOCK_SIZE,
+                                             MBEDTLS_ENTROPY_SOURCE_STRONG ) == 0 );
+
+    // Do an entropy run
+    TEST_ASSERT( mbedtls_entropy_func( &ctx, entropy, sizeof( entropy ) ) == 0 );
+
+    // Determine what should have happened with manual entropy internal logic
+    // Only use the SHA-512 version to check
+
+    // Init accumulator
+    header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE;
+    mbedtls_sha512_starts( &accumulator, 0 );
+
+    // First run for updating write_seed
+    header[0] = 0;
+    mbedtls_sha512_update( &accumulator, header, 2 );
+    mbedtls_sha512_update( &accumulator, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    mbedtls_sha512_finish( &accumulator, buf );
+
+    memset( &accumulator, 0, sizeof( mbedtls_sha512_context ) );
+    mbedtls_sha512_starts( &accumulator, 0 );
+    mbedtls_sha512_update( &accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_seed, 0 );
+
+    // Second run for actual entropy (triggers mbedtls_entropy_update_nv_seed)
+    header[0] = MBEDTLS_ENTROPY_SOURCE_MANUAL;
+    mbedtls_sha512_update( &accumulator, header, 2 );
+    mbedtls_sha512_update( &accumulator, empty, MBEDTLS_ENTROPY_BLOCK_SIZE );
+
+    header[0] = 0;
+    mbedtls_sha512_update( &accumulator, header, 2 );
+    mbedtls_sha512_update( &accumulator, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE );
+    mbedtls_sha512_finish( &accumulator, buf );
+
+    mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_entropy, 0 );
+
+    // Check result of both NV file and entropy received with the manual calculations
+    TEST_ASSERT( memcmp( check_seed, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+    TEST_ASSERT( memcmp( check_entropy, entropy, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 );
+
+    mbedtls_entropy_free( &ctx );
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */
 void entropy_selftest( )
 {