Update example in BlockDevice.md

Replace hardcoded example with importable one.

Author: Amanda Butler

docs/api/storage/BlockDevice.md

@@ -42,108 +42,7 @@ For details regarding how to configure the default block device please refer to
 
 ### BlockDevice example
 
-```
-/* mbed Microcontroller Library
- * Copyright (c) 2006-2013 ARM Limited
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-#include "mbed.h"
-#include "BlockDevice.h"
-#include <stdio.h>
-#include <algorithm>
-
- // This will take the system's default block device 
-BlockDevice *bd = BlockDevice::get_default_instance();
-
-// Instead of the default block device, you can define your own block device.
-// For example: HeapBlockDevice with size of 2048 bytes, read size 1, write size 1 and erase size 512.
-// #include "HeapBlockDevice.h"
-// BlockDevice *bd = new HeapBlockDevice(2048, 1, 1, 512);
-
-// Entry point for the example
-int main() {
-    printf("--- Mbed OS block device example ---\n");
-
-    // Initialize the block device
-    printf("bd->init()\n");
-    int err = bd->init();
-    printf("bd->init -> %d\n", err);
-
-    // Get device geometry
-    bd_size_t read_size    = bd->get_read_size();
-    bd_size_t program_size = bd->get_program_size();
-    bd_size_t erase_size   = bd->get_erase_size();
-    bd_size_t size         = bd->size();
-
-    printf("--- Block device geometry ---\n");
-    printf("read_size:    %lld B\n", read_size);
-    printf("program_size: %lld B\n", program_size);
-    printf("erase_size:   %lld B\n", erase_size);
-    printf("size:         %lld B\n", size);
-    printf("---\n");
-
-    // Allocate a block with enough space for our data, aligned to the
-    // nearest program_size. This is the minimum size necessary to write
-    // data to a block.
-    size_t buffer_size = sizeof("Hello Storage!") + program_size-1;
-    buffer_size = buffer_size - (buffer_size % program_size);
-    char *buffer = new char[buffer_size];
-
-    // Update buffer with our string we want to store
-    strncpy(buffer, "Hello Storage!", buffer_size);
-
-    // Write data to first block, write occurs in two parts,
-    // an erase followed by a program
-    printf("bd->erase(%d, %lld)\n", 0, erase_size);
-    err = bd->erase(0, erase_size);
-    printf("bd->erase -> %d\n", err);
-
-    printf("bd->program(%p, %d, %d)\n", buffer, 0, buffer_size);
-    err = bd->program(buffer, 0, buffer_size);
-    printf("bd->program -> %d\n", err);
-
-    // Clobber the buffer so we don't get old data
-    memset(buffer, 0xcc, buffer_size);
-
-    // Read the data from the first block, note that the program_size must be
-    // a multiple of the read_size, so we don't have to check for alignment
-    printf("bd->read(%p, %d, %d)\n", buffer, 0, buffer_size);
-    err = bd->read(buffer, 0, buffer_size);
-    printf("bd->read -> %d\n", err);
-
-    printf("--- Stored data ---\n");
-    for (size_t i = 0; i < buffer_size; i += 16) {
-        for (size_t j = 0; j < 16; j++) {
-            if (i+j < buffer_size) {
-                printf("%02x ", buffer[i+j]);
-            } else {
-                printf("   ");
-            }
-        }
-
-        printf(" %.*s\n", buffer_size - i, &buffer[i]);
-    }
-    printf("---\n");
-
-    // Deinitialize the block device
-    printf("bd->deinit()\n");
-    err = bd->deinit();
-    printf("bd->deinit -> %d\n", err);
-
-    printf("--- done! ---\n");
-}
-```
+[![View code](https://www.mbed.com/embed/?url=https://github.com/ARMmbed/mbed-os-examples-docs_only/blob/master/blockdevices/BlockDevice/)](https://github.com/ARMmbed/mbed-os-examples-docs_only/blob/master/blockdevices/BlockDevice/main.cpp)
 
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