Add material for generating yotta module
diff --git a/yotta/data/example-tls-client/main.cpp b/yotta/data/example-tls-client/main.cpp
new file mode 100644
index 0000000..970788c
--- /dev/null
+++ b/yotta/data/example-tls-client/main.cpp
@@ -0,0 +1,489 @@
+/*
+ *  Hello world example of a TLS client: fetch an HTTPS page
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+#if !defined(TARGET_LIKE_MBED)
+
+#include <stdio.h>
+
+int main() {
+    printf("this program only works on mbed OS\n");
+    return 0;
+}
+
+#else
+
+/** \file main.cpp
+ *  \brief An example TLS Client application
+ *  This application sends an HTTPS request to developer.mbed.org and searches for a string in
+ *  the result.
+ *
+ *  This example is implemented as a logic class (HelloHTTPS) wrapping a TCP socket.
+ *  The logic class handles all events, leaving the main loop to just check if the process
+ *  has finished.
+ */
+
+/* Change to a number between 1 and 4 to debug the TLS connection */
+#define DEBUG_LEVEL 0
+
+/* Change to 1 to skip certificate verification (UNSAFE, for debug only!) */
+#define UNSAFE 0
+
+#include "mbed.h"
+#include <mbed-net-lwip-eth/EthernetInterface.h>
+#include <mbed-net-sockets/TCPStream.h>
+
+#include "mbedtls/ssl.h"
+#include "mbedtls/entropy.h"
+#include "mbedtls/ctr_drbg.h"
+#include "mbedtls/error.h"
+#if DEBUG_LEVEL > 0
+#include "mbedtls/debug.h"
+#endif
+
+#include "lwipv4_init.h"
+
+namespace {
+const char *HTTPS_SERVER_NAME = "developer.mbed.org";
+const int HTTPS_SERVER_PORT = 443;
+const int RECV_BUFFER_SIZE = 600;
+
+const char HTTPS_PATH[] = "/media/uploads/mbed_official/hello.txt";
+const size_t HTTPS_PATH_LEN = sizeof(HTTPS_PATH) - 1;
+
+/* Test related data */
+const char *HTTPS_OK_STR = "200 OK";
+const char *HTTPS_HELLO_STR = "Hello world!";
+
+/* personalization string for the drbg */
+const char *DRBG_PERS = "mbed TLS helloword client";
+
+/* List of trusted root CA certificates
+ * currently just Verisign since it's the root used by developer.mbed.org
+ * If you want to trust more that one root, just concatenate them.
+ */
+const char SSL_CA_PEM[] =
+"-----BEGIN CERTIFICATE-----\n"
+"MIIDdTCCAl2gAwIBAgILBAAAAAABFUtaw5QwDQYJKoZIhvcNAQEFBQAwVzELMAkG\n"
+"A1UEBhMCQkUxGTAXBgNVBAoTEEdsb2JhbFNpZ24gbnYtc2ExEDAOBgNVBAsTB1Jv\n"
+"b3QgQ0ExGzAZBgNVBAMTEkdsb2JhbFNpZ24gUm9vdCBDQTAeFw05ODA5MDExMjAw\n"
+"MDBaFw0yODAxMjgxMjAwMDBaMFcxCzAJBgNVBAYTAkJFMRkwFwYDVQQKExBHbG9i\n"
+"YWxTaWduIG52LXNhMRAwDgYDVQQLEwdSb290IENBMRswGQYDVQQDExJHbG9iYWxT\n"
+"aWduIFJvb3QgQ0EwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDaDuaZ\n"
+"jc6j40+Kfvvxi4Mla+pIH/EqsLmVEQS98GPR4mdmzxzdzxtIK+6NiY6arymAZavp\n"
+"xy0Sy6scTHAHoT0KMM0VjU/43dSMUBUc71DuxC73/OlS8pF94G3VNTCOXkNz8kHp\n"
+"1Wrjsok6Vjk4bwY8iGlbKk3Fp1S4bInMm/k8yuX9ifUSPJJ4ltbcdG6TRGHRjcdG\n"
+"snUOhugZitVtbNV4FpWi6cgKOOvyJBNPc1STE4U6G7weNLWLBYy5d4ux2x8gkasJ\n"
+"U26Qzns3dLlwR5EiUWMWea6xrkEmCMgZK9FGqkjWZCrXgzT/LCrBbBlDSgeF59N8\n"
+"9iFo7+ryUp9/k5DPAgMBAAGjQjBAMA4GA1UdDwEB/wQEAwIBBjAPBgNVHRMBAf8E\n"
+"BTADAQH/MB0GA1UdDgQWBBRge2YaRQ2XyolQL30EzTSo//z9SzANBgkqhkiG9w0B\n"
+"AQUFAAOCAQEA1nPnfE920I2/7LqivjTFKDK1fPxsnCwrvQmeU79rXqoRSLblCKOz\n"
+"yj1hTdNGCbM+w6DjY1Ub8rrvrTnhQ7k4o+YviiY776BQVvnGCv04zcQLcFGUl5gE\n"
+"38NflNUVyRRBnMRddWQVDf9VMOyGj/8N7yy5Y0b2qvzfvGn9LhJIZJrglfCm7ymP\n"
+"AbEVtQwdpf5pLGkkeB6zpxxxYu7KyJesF12KwvhHhm4qxFYxldBniYUr+WymXUad\n"
+"DKqC5JlR3XC321Y9YeRq4VzW9v493kHMB65jUr9TU/Qr6cf9tveCX4XSQRjbgbME\n"
+"HMUfpIBvFSDJ3gyICh3WZlXi/EjJKSZp4A==\n"
+"-----END CERTIFICATE-----\n";
+}
+
+/**
+ * \brief HelloHTTPS implements the logic for fetching a file from a webserver
+ * using a TCP socket and parsing the result.
+ */
+class HelloHTTPS {
+public:
+    /**
+     * HelloHTTPS Constructor
+     * Initializes the TCP socket, sets up event handlers and flags.
+     *
+     * Note that CThunk is used for event handlers.  This will be changed to a C++
+     * function pointer in an upcoming release.
+     *
+     *
+     * @param[in] domain The domain name to fetch from
+     * @param[in] port The port of the HTTPS server
+     */
+    HelloHTTPS(const char * domain, const uint16_t port) :
+            _stream(SOCKET_STACK_LWIP_IPV4), _domain(domain), _port(port)
+    {
+
+        _error = false;
+        _gothello = false;
+        _got200 = false;
+        _bpos = 0;
+        _request_sent = 0;
+        _stream.open(SOCKET_AF_INET4);
+
+        mbedtls_entropy_init(&_entropy);
+        mbedtls_ctr_drbg_init(&_ctr_drbg);
+        mbedtls_x509_crt_init(&_cacert);
+        mbedtls_ssl_init(&_ssl);
+        mbedtls_ssl_config_init(&_ssl_conf);
+    }
+    /**
+     * Initiate the test.
+     *
+     * Starts by clearing test flags, then resolves the address with DNS.
+     *
+     * @param[in] path The path of the file to fetch from the HTTPS server
+     * @return SOCKET_ERROR_NONE on success, or an error code on failure
+     */
+    socket_error_t startTest(const char *path) {
+        /* Initialize the flags */
+        _got200 = false;
+        _gothello = false;
+        _error = false;
+        _disconnected = false;
+        _request_sent = false;
+        /* Fill the request buffer */
+        _bpos = snprintf(_buffer, sizeof(_buffer) - 1, "GET %s HTTP/1.1\nHost: %s\n\n", path, HTTPS_SERVER_NAME);
+
+        /*
+         * Initialize TLS-related stuf.
+         */
+        int ret;
+        if ((ret = mbedtls_ctr_drbg_seed(&_ctr_drbg, mbedtls_entropy_func, &_entropy,
+                          (const unsigned char *) DRBG_PERS,
+                          sizeof (DRBG_PERS))) != 0) {
+            print_mbedtls_error("mbedtls_crt_drbg_init", ret);
+            return SOCKET_ERROR_UNKNOWN;
+        }
+
+        if ((ret = mbedtls_x509_crt_parse(&_cacert, (const unsigned char *) SSL_CA_PEM,
+                           sizeof (SSL_CA_PEM))) != 0) {
+            print_mbedtls_error("mbedtls_x509_crt_parse", ret);
+            return SOCKET_ERROR_UNKNOWN;
+        }
+
+        if ((ret = mbedtls_ssl_config_defaults(&_ssl_conf,
+                        MBEDTLS_SSL_IS_CLIENT,
+                        MBEDTLS_SSL_TRANSPORT_STREAM,
+                        MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
+            print_mbedtls_error("mbedtls_ssl_config_defaults", ret);
+            return SOCKET_ERROR_UNKNOWN;
+        }
+
+        mbedtls_ssl_conf_ca_chain(&_ssl_conf, &_cacert, NULL);
+        mbedtls_ssl_conf_rng(&_ssl_conf, mbedtls_ctr_drbg_random, &_ctr_drbg);
+
+#if UNSAFE
+        mbedtls_ssl_conf_authmode(&_ssl_conf, MBEDTLS_SSL_VERIFY_OPTIONAL);
+#endif
+
+#if DEBUG_LEVEL > 0
+        mbedtls_ssl_conf_verify(&_ssl_conf, my_verify, NULL);
+        mbedtls_ssl_conf_dbg(&_ssl_conf, my_debug, NULL);
+        mbedtls_debug_set_threshold(DEBUG_LEVEL);
+#endif
+
+        if ((ret = mbedtls_ssl_setup(&_ssl, &_ssl_conf)) != 0) {
+            print_mbedtls_error("mbedtls_ssl_setup", ret);
+            return SOCKET_ERROR_UNKNOWN;
+        }
+
+        mbedtls_ssl_set_hostname(&_ssl, HTTPS_SERVER_NAME);
+
+        mbedtls_ssl_set_bio(&_ssl, static_cast<void *>(&_stream),
+                                   ssl_send, ssl_recv, NULL );
+
+
+        /* Connect to the server */
+        printf("Connecting to %s:%d\r\n", _domain, _port);
+        /* Resolve the domain name: */
+        socket_error_t err = _stream.resolve(_domain, handler_t(this, &HelloHTTPS::onDNS));
+        return err;
+    }
+    /**
+     * Check if the test has completed.
+     * @return Returns true if done, false otherwise.
+     */
+    bool done() {
+        return _error || (_got200 && _gothello);
+    }
+    /**
+     * Check if there was an error
+     * @return Returns true if there was an error, false otherwise.
+     */
+    bool error() {
+        return _error;
+    }
+    /**
+     * Closes the TCP socket
+     */
+    void close() {
+        _stream.close();
+        while (!_disconnected)
+            __WFI();
+    }
+protected:
+    /**
+     * Helper for pretty-printing mbed TLS error codes
+     */
+    static void print_mbedtls_error(const char *name, int err) {
+        char buf[128];
+        mbedtls_strerror(err, buf, sizeof (buf));
+        printf("%s() failed: -0x%04x (%d): %s\r\n", name, -err, err, buf);
+    }
+
+#if DEBUG_LEVEL > 0
+    /**
+     * Debug callback for mbed TLS
+     * Just prints on the USB serial port
+     */
+    static void my_debug(void *ctx, int level, const char *str)
+    {
+        (void) ctx;
+        (void) level;
+
+        printf("%s", str);
+    }
+
+    /**
+     * Certificate verification callback for mbed TLS
+     * Here we only use it to display information on each cert in the chain
+     */
+    static int my_verify(void *data, mbedtls_x509_crt *crt, int depth, int *flags)
+    {
+        char buf[1024];
+        (void) data;
+
+        printf("\nVerifying certificate at depth %d:\n", depth);
+        mbedtls_x509_crt_info(buf, sizeof (buf) - 1, "  ", crt);
+        printf("%s", buf);
+
+        if (*flags == 0)
+            printf("No verification issue for this certificate\n");
+        else
+        {
+            mbedtls_x509_crt_verify_info(buf, sizeof (buf), "  ! ", *flags);
+            printf("%s\n", buf);
+        }
+
+        return 0;
+    }
+#endif
+
+    /**
+     * Receive callback for mbed TLS
+     */
+    static int ssl_recv(void *ctx, unsigned char *buf, size_t len) {
+        mbed::TCPStream *stream = static_cast<mbed::TCPStream *>(ctx);
+        socket_error_t err = stream->recv(buf, &len);
+
+        if (err == SOCKET_ERROR_NONE) {
+            return static_cast<int>(len);
+        } else if (err == SOCKET_ERROR_WOULD_BLOCK) {
+            return MBEDTLS_ERR_SSL_WANT_READ;
+        } else {
+            return -1;
+        }
+    }
+
+    /**
+     * Send callback for mbed TLS
+     */
+    static int ssl_send(void *ctx, const unsigned char *buf, size_t len) {
+        mbed::TCPStream *stream = static_cast<mbed::TCPStream *>(ctx);
+
+        socket_error_t err = stream->send(buf, len);
+
+        if (err == SOCKET_ERROR_NONE) {
+            return static_cast<int>(len);
+        } else if (err == SOCKET_ERROR_WOULD_BLOCK) {
+            return MBEDTLS_ERR_SSL_WANT_WRITE;
+        } else {
+            return -1;
+        }
+    }
+
+    /**
+     * On Connect handler
+     * Sends the request which was generated in startTest
+     */
+    void onConnect(socket_error_t err) {
+        (void) err;
+
+        _stream.setOnReadable(handler_t(this, &HelloHTTPS::onReceive));
+        _stream.setOnDisconnect(handler_t(this, &HelloHTTPS::onDisconnect));
+
+        /* Start the handshake, the rest will be done in onReceive() */
+        int ret = mbedtls_ssl_handshake(&_ssl);
+        if (ret < 0) {
+            if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
+                ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
+                print_mbedtls_error("mbedtls_ssl_handshake", ret);
+                _error = true;
+            }
+            return;
+        }
+    }
+    /**
+     * On Receive handler
+     * Parses the response from the server, to check for the HTTPS 200 status code and the expected response ("Hello World!")
+     */
+    void onReceive(socket_error_t err) {
+        (void) err;
+
+        if (_error)
+            return;
+
+        /* Send request if not done yet */
+        if (!_request_sent) {
+            int ret = mbedtls_ssl_write(&_ssl, (const unsigned char *) _buffer, _bpos);
+            if (ret < 0) {
+                if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
+                    ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
+                    print_mbedtls_error("mbedtls_ssl_write", ret);
+                    _error = true;
+                }
+                return;
+            }
+
+            /* If we get here, the request was sent */
+            _request_sent = 1;
+
+            /* It also means the handshake is done, time to print info */
+            printf("TLS connection to %s established\r\n", HTTPS_SERVER_NAME);
+            {
+                char buf[1024];
+                mbedtls_x509_crt_info(buf, sizeof(buf), "\r    ",
+                        mbedtls_ssl_get_peer_cert(&_ssl));
+                printf("Server certificate:\r\n%s\r", buf);
+
+#if defined(UNSAFE)
+                uint32_t flags = mbedtls_ssl_get_verify_result(&_ssl);
+                if( flags != 0 )
+                {
+                    mbedtls_x509_crt_verify_info(buf, sizeof (buf), "\r  ! ", flags);
+                    printf("Certificate verification failed:\r\n%s\r\r\n", buf);
+                }
+                else
+#endif
+                    printf("Certificate verification passed\r\n\r\n");
+            }
+        }
+
+        /* Read data out of the socket */
+        int ret = mbedtls_ssl_read(&_ssl, (unsigned char *) _buffer, sizeof(_buffer));
+        if (ret < 0) {
+            if (ret != MBEDTLS_ERR_SSL_WANT_READ &&
+                ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
+                    print_mbedtls_error("mbedtls_ssl_read", ret);
+                _error = true;
+            }
+            return;
+        }
+        _bpos = static_cast<size_t>(ret);
+
+        _buffer[_bpos] = 0;
+
+        /* Check each of the flags */
+        _got200 = _got200 || strstr(_buffer, HTTPS_OK_STR) != NULL;
+        _gothello = _gothello || strstr(_buffer, HTTPS_HELLO_STR) != NULL;
+
+        /* Print status messages */
+        printf("HTTPS: Received %d chars from server\r\n", _bpos);
+        printf("HTTPS: Received 200 OK status ... %s\r\n", _got200 ? "[OK]" : "[FAIL]");
+        printf("HTTPS: Received '%s' status ... %s\r\n", HTTPS_HELLO_STR, _gothello ? "[OK]" : "[FAIL]");
+        printf("HTTPS: Received message:\r\n\r\n");
+        printf("%s", _buffer);
+        _error = !(_got200 && _gothello);
+    }
+    /**
+     * On DNS Handler
+     * Reads the address returned by DNS, then starts the connect process.
+     */
+    void onDNS(socket_error_t err) {
+        socket_event_t *e = _stream.getEvent();
+        /* Check that the result is a valid DNS response */
+        if (socket_addr_is_any(&e->i.d.addr)) {
+            /* Could not find DNS entry */
+            _error = true;
+            printf("Could not find DNS entry for %s", HTTPS_SERVER_NAME);
+            return;
+        } else {
+            /* Start connecting to the remote host */
+            _remoteAddr.setAddr(&e->i.d.addr);
+            err = _stream.connect(&_remoteAddr, _port, handler_t(this, &HelloHTTPS::onConnect));
+
+            if (err != SOCKET_ERROR_NONE) {
+                _error = true;
+            }
+        }
+    }
+    void onDisconnect(socket_error_t err) {
+        (void) err;
+        _disconnected = true;
+    }
+
+protected:
+    mbed::TCPStream _stream;        /**< The TCP Socket */
+    const char *_domain;            /**< The domain name of the HTTPS server */
+    const uint16_t _port;           /**< The HTTPS server port */
+    char _buffer[RECV_BUFFER_SIZE]; /**< The response buffer */
+    size_t _bpos;                   /**< The current offset in the response buffer */
+    mbed::SocketAddr _remoteAddr;   /**< The remote address */
+    volatile bool _got200;          /**< Status flag for HTTPS 200 */
+    volatile bool _gothello;        /**< Status flag for finding the test string */
+    volatile bool _error;           /**< Status flag for an error */
+    volatile bool _disconnected;
+    volatile bool _request_sent;
+
+    mbedtls_entropy_context _entropy;
+    mbedtls_ctr_drbg_context _ctr_drbg;
+    mbedtls_x509_crt _cacert;
+    mbedtls_ssl_context _ssl;
+    mbedtls_ssl_config _ssl_conf;
+};
+
+/**
+ * The main loop of the HTTPS Hello World test
+ */
+int example_client() {
+    EthernetInterface eth;
+    /* Initialise with DHCP, connect, and start up the stack */
+    eth.init();
+    eth.connect();
+    lwipv4_socket_init();
+
+    printf("\r\n\r\n");
+    printf("Client IP Address is %s\r\n", eth.getIPAddress());
+
+    HelloHTTPS hello(HTTPS_SERVER_NAME, HTTPS_SERVER_PORT);
+    socket_error_t rc = hello.startTest(HTTPS_PATH);
+    if (rc != SOCKET_ERROR_NONE) {
+        return 1;
+    }
+    while (!hello.done()) {
+        __WFI();
+    }
+    if (hello.error()) {
+        printf("Failed to fetch %s from %s:%d\r\n", HTTPS_PATH, HTTPS_SERVER_NAME, HTTPS_SERVER_PORT);
+    }
+    /* Shut down the socket before the ethernet interface */
+    hello.close();
+    eth.disconnect();
+    return static_cast<int>(hello.error());
+}
+
+#include "mbed/test_env.h"
+
+int main() {
+    /* The default 9600 bps is too slow to print full TLS debug info and could
+     * cause the other party to time out. Select a higher baud rate for
+     * printf(), regardless of debug level for the sake of uniformity. */
+    Serial pc(USBTX, USBRX);
+    pc.baud(115200);
+
+    MBED_HOSTTEST_TIMEOUT(120);
+    MBED_HOSTTEST_SELECT(default);
+    MBED_HOSTTEST_DESCRIPTION(mbed TLS example HTTPS client);
+    MBED_HOSTTEST_START("MBEDTLS_EX_HTTPS_CLIENT");
+    MBED_HOSTTEST_RESULT(example_client() == 0);
+}
+
+#endif /* TARGET_LIKE_MBED */