read/write first attempt

CMakeLists.txt

@@ -25,7 +25,10 @@ pico_sdk_init()
 
 # Add executable. Default name is the project name, version 0.1
 
-add_executable(pico_keyer pico_keyer.cpp )
+add_executable(pico_keyer
+  pico_keyer.cpp
+  settings.cpp
+)
 
 pico_set_program_name(pico_keyer "pico_keyer")
 pico_set_program_version(pico_keyer "0.1")
@@ -48,6 +51,7 @@ target_link_libraries(pico_keyer
   hardware_flash
   hardware_exception
   pico_flash
+  pico_mem_ops
 )
 
 pico_add_extra_outputs(pico_keyer)

pico_keyer.cpp

@@ -1,5 +1,5 @@
 #include <stdio.h>
-#include "pico/stdlib.h"
+#include <pico/stdlib.h>
 
 #include "settings.h"
 
@@ -16,5 +16,17 @@ int main()
 
     puts("Hello, world!");
 
+    Settings settings;
+    settings.mode = Mode::IAMBIC_A;
+    store_settings(settings);
+    printf("Iambic mode (stored): %d", static_cast<int>(settings.mode));
+    sleep_ms(1000);
+    Settings newSettings = read_settings();
+    printf("Iambic mode (loaded): %d", static_cast<int>(newSettings.mode));
+
+    while(true) {
+        sleep_ms(1000);
+    }
+
     return 0;
 }

settings.cpp

@@ -1,19 +1,30 @@
+#include <cstring>
+
 #include "settings.h"
 
 namespace
 {
-    const size_t PAGE_SIZE{256};
+    constexpr const uint32_t FLASH_TARGET_OFFSET = PICO_FLASH_SIZE_BYTES - FLASH_SECTOR_SIZE;
-    const size_t NVS_SIZE{4096};
+    const uint8_t *flash_target_contents = (const uint8_t *) (XIP_BASE + FLASH_TARGET_OFFSET);
-    const uint32_t FLASH_WRITE_START = PICO_FLASH_SIZE_BYTES - NVS_SIZE;
 }
 
 void flash_store_callback(void *settings)
 {
-    flash_range_erase(FLASH_WRITE_START, NVS_SIZE);
+    int writeSize = (sizeof(struct Settings) / FLASH_PAGE_SIZE) + 1;
-    flash_range_program(FLASH_WRITE_START, (const uint8_t *)settings, PAGE_SIZE);
+
+    flash_range_erase(FLASH_TARGET_OFFSET, FLASH_SECTOR_SIZE);
+    flash_range_program(FLASH_TARGET_OFFSET, reinterpret_cast<uint8_t *>(settings), FLASH_PAGE_SIZE * writeSize);
 }
 
 void store_settings(Settings &settings)
 {
-    flash_safe_execute(flash_store_callback, (void *)&settings, 1000);
+    uint8_t *settingsAsBytes = reinterpret_cast<uint8_t *>(&settings);
+
+    flash_safe_execute(flash_store_callback, settingsAsBytes, 1000);
+}
+
+Settings read_settings() {
+    Settings settings;
+    memcpy(&settings, flash_target_contents, sizeof(struct Settings));
+    return settings;
 }

settings.h

@@ -1,7 +1,7 @@
 #ifndef SETTINGS_H
 #define SETTINGS_H
 
-#include "pico/flash.h"
+#include <pico/flash.h>
 
 enum class Mode
 {
@@ -16,7 +16,7 @@ struct Settings
 };
 
 void store_settings(Settings &settings);
-
+Settings read_settings();
 
 
 #endif