Flash Key Value - tutoria's sketch added

Author: marqdevx

examples/10. Flash_Key_Value/10. Flash_Key_Value.ino

@@ -0,0 +1,133 @@
+#include <FlashIAPBlockDevice.h>
+#include <TDBStore.h>
+
+using namespace mbed;
+
+// Get limits of the In Application Program (IAP) flash, ie. the internal MCU flash.
+#include "FlashIAPLimits.h"
+auto iapLimits { getFlashIAPLimits() };
+
+// Create a block device on the available space of the FlashIAP
+FlashIAPBlockDevice blockDevice(iapLimits.start_address, iapLimits.available_size);
+
+// Create a key/value store on the Flash IAP block device
+TDBStore store(&blockDevice);
+
+// Dummy sketch stats for demonstration purposes
+struct SketchStats {
+    uint32_t startupTime;
+    uint32_t randomValue;
+    uint32_t runCount;
+};
+
+void setup()
+{
+    Serial.begin(115200);
+    while (!Serial);
+
+    //  Wait for terminal to come up
+    delay(1000);
+
+    Serial.println("FlashIAPBlockDevice + TDBStore Test");
+
+    // Feed the RNG for later content generation
+    srand(micros());
+
+    // Initialize the flash IAP block device and print the memory layout
+    blockDevice.init();
+    Serial.printf("FlashIAP block device size: %llu\r\n", blockDevice.size());
+    Serial.printf("FlashIAP block device read size: %llu\r\n", blockDevice.get_read_size());
+    Serial.printf("FlashIAP block device program size: %llu\r\n", blockDevice.get_program_size());
+    Serial.printf("FlashIAP block device erase size: %llu\r\n", blockDevice.get_erase_size());
+    // Deinitialize the device
+    blockDevice.deinit();
+
+    // Initialize the key/value store
+    Serial.print("Initializing TDBStore: ");
+    auto result = store.init();
+    Serial.println(result == MBED_SUCCESS ? "OK" : "KO");
+    if (result != MBED_SUCCESS)
+        while (true);
+
+    // An example key name for the stats on the store
+    const char statsKey[] { "stats" };
+
+    // Keep track of the number of sketch executions
+    uint32_t runCount { 0 };
+
+    // Previous stats
+    SketchStats previousStats;
+
+    // Get previous run stats from the key/value store
+    Serial.println("Retrieving Sketch Stats");
+    result = getSketchStats(statsKey, &previousStats);
+    if (result == MBED_SUCCESS) {
+        Serial.println("Previous Stats");
+        Serial.print("\tStartup Time: ");
+        Serial.println(previousStats.startupTime);
+        Serial.print("\tRandom Value: ");
+        Serial.println(previousStats.randomValue);
+        Serial.print("\tRun Count: ");
+        Serial.println(previousStats.runCount);
+
+        runCount = previousStats.runCount;
+
+    } else if (result == MBED_ERROR_ITEM_NOT_FOUND) {
+        Serial.println("First execution");
+    } else {
+        Serial.println("Error reading from key/value store.");
+        while (true);
+    }
+
+    //Update the stats and save them to the store
+    SketchStats currentStats { millis(), rand(), ++runCount };
+    result = setSketchStats(statsKey, currentStats);
+    
+    if (result == MBED_SUCCESS) {
+        Serial.println("Sketch Stats updated");
+        Serial.println("Current Stats");
+        Serial.print("\tStartup Time: ");
+        Serial.println(currentStats.startupTime);
+        Serial.print("\tRandom Value: ");
+        Serial.println(currentStats.randomValue);
+        Serial.print("\tRun Count: ");
+        Serial.println(currentStats.runCount);
+    } else {
+        Serial.println("Error storing to key/value store");
+        while (true);
+    }
+}
+
+void loop()
+{
+    // Do nothing
+}
+
+// Retrieve a SketchStats from the k/v store
+int getSketchStats(const char* key, SketchStats* stats)
+{
+    // Retrieve key/value info
+    TDBStore::info_t info;
+    auto result = store.get_info(key, &info);
+    if (result == MBED_ERROR_ITEM_NOT_FOUND)
+        return result;
+
+    // Allocate space for the value
+    uint8_t buffer[info.size] {};
+    size_t actual_size;
+
+    // Get the value
+    result = store.get(key, buffer, sizeof(buffer), &actual_size);
+    if (result != MBED_SUCCESS)
+        return result;
+
+    memcpy(stats, buffer, sizeof(SketchStats));
+    return result;
+}
+
+// Store a SketchStats to the the k/v store
+int setSketchStats(const char* key, SketchStats stats)
+{
+    auto result = store.set(key, reinterpret_cast<uint8_t*>(&stats), sizeof(SketchStats), 0);
+    return result;
+}

examples/10. Flash_Key_Value/FlashIAPLimits.h

@@ -0,0 +1,51 @@
+/**
+ * Helper functions for calculating limits for the FlashIAP block device
+ * */
+
+#pragma once
+
+#include <Arduino.h>
+#include <FlashIAP.h>
+#include <FlashIAPBlockDevice.h>
+
+using namespace mbed;
+
+// An helper struct for FlashIAP limits
+struct FlashIAPLimits {
+    size_t flash_size;
+    uint32_t start_address;
+    uint32_t available_size;
+};
+
+// Get the actual start address and available size for the FlashIAP Block Device
+// considering the space already occupied by the sketch.
+FlashIAPLimits getFlashIAPLimits()
+{
+    // Alignment lambdas
+    auto align_down = [](uint64_t val, uint64_t size) { return (((val) / size)) * size; };
+    auto align_up = [](uint32_t val, uint32_t size) { return (((val - 1) / size) + 1) * size; };
+
+    size_t flash_size;
+    uint32_t flash_start_address;
+    uint32_t start_address;
+    FlashIAP flash;
+
+    auto result = flash.init();
+    if (result != 0)
+        return { };
+
+    // Find the start of first sector after text area
+    int sector_size = flash.get_sector_size(FLASHIAP_APP_ROM_END_ADDR);
+    start_address = align_up(FLASHIAP_APP_ROM_END_ADDR, sector_size);
+    flash_start_address = flash.get_flash_start();
+    flash_size = flash.get_flash_size();
+
+    result = flash.deinit();
+
+    int available_size = flash_start_address + flash_size - start_address;
+    if (available_size % (sector_size * 2)) {
+        available_size = align_down(available_size, sector_size * 2);
+    }
+
+    return { flash_size, start_address, available_size };
+}