[FL-1994] Add Saved Struct (#804)

Co-authored-by: あく <alleteam@gmail.com>

applications/desktop/desktop.c

@@ -1,4 +1,5 @@
 #include "desktop_i.h"
+#include <furi-hal-lock.h>
 
 static void desktop_lock_icon_callback(Canvas* canvas, void* context) {
     furi_assert(canvas);
@@ -117,9 +118,23 @@ static bool desktop_is_first_start() {
 
 int32_t desktop_srv(void* p) {
     Desktop* desktop = desktop_alloc();
+    bool loaded = LOAD_DESKTOP_SETTINGS(&desktop->settings);
+    if(!loaded) {
+        furi_hal_lock_set(false);
+        memset(&desktop->settings, 0, sizeof(desktop->settings));
+        bool saved = SAVE_DESKTOP_SETTINGS(&desktop->settings);
+        furi_check(saved);
+    }
 
     scene_manager_next_scene(desktop->scene_manager, DesktopSceneMain);
 
+    if(furi_hal_lock_get()) {
+        furi_hal_usb_disable();
+        scene_manager_set_scene_state(
+            desktop->scene_manager, DesktopSceneLocked, DesktopLockedWithPin);
+        scene_manager_next_scene(desktop->scene_manager, DesktopSceneLocked);
+    }
+
     if(desktop_is_first_start()) {
         scene_manager_next_scene(desktop->scene_manager, DesktopSceneFirstStart);
     }

applications/desktop/desktop_settings/desktop_settings.c

@@ -1,49 +0,0 @@
-#include <furi.h>
-#include <file-worker.h>
-#include "desktop_settings.h"
-
-#define DESKTOP_SETTINGS_TAG "Desktop settings"
-#define DESKTOP_SETTINGS_PATH "/int/desktop.settings"
-
-bool desktop_settings_load(DesktopSettings* desktop_settings) {
-    furi_assert(desktop_settings);
-    bool file_loaded = false;
-    DesktopSettings settings = {};
-
-    FURI_LOG_I(DESKTOP_SETTINGS_TAG, "Loading settings from \"%s\"", DESKTOP_SETTINGS_PATH);
-    FileWorker* file_worker = file_worker_alloc(true);
-    if(file_worker_open(file_worker, DESKTOP_SETTINGS_PATH, FSAM_READ, FSOM_OPEN_EXISTING)) {
-        if(file_worker_read(file_worker, &settings, sizeof(settings))) {
-            file_loaded = true;
-        }
-    }
-    file_worker_free(file_worker);
-
-    if(file_loaded) {
-        if(settings.version != DESKTOP_SETTINGS_VER) {
-            FURI_LOG_E(DESKTOP_SETTINGS_TAG, "Settings version mismatch");
-        } else {
-            osKernelLock();
-            *desktop_settings = settings;
-            osKernelUnlock();
-        }
-    } else {
-        FURI_LOG_E(DESKTOP_SETTINGS_TAG, "Settings load failed");
-    }
-    return file_loaded;
-}
-
-bool desktop_settings_save(DesktopSettings* desktop_settings) {
-    furi_assert(desktop_settings);
-    bool result = false;
-
-    FileWorker* file_worker = file_worker_alloc(true);
-    if(file_worker_open(file_worker, DESKTOP_SETTINGS_PATH, FSAM_WRITE, FSOM_OPEN_ALWAYS)) {
-        if(file_worker_write(file_worker, desktop_settings, sizeof(DesktopSettings))) {
-            FURI_LOG_I(DESKTOP_SETTINGS_TAG, "Settings saved to \"%s\"", DESKTOP_SETTINGS_PATH);
-            result = true;
-        }
-    }
-    file_worker_free(file_worker);
-    return result;
-}

applications/desktop/desktop_settings/desktop_settings.h

@@ -2,23 +2,35 @@
 
 #include <stdint.h>
 #include <stdbool.h>
+#include <toolbox/saved_struct.h>
 
 #define DESKTOP_SETTINGS_VER (1)
+#define DESKTOP_SETTINGS_PATH "/int/desktop.settings"
+#define DESKTOP_SETTINGS_MAGIC (0x17)
 #define PIN_MAX_LENGTH 12
 
+#define SAVE_DESKTOP_SETTINGS(x) \
+    saved_struct_save(           \
+        DESKTOP_SETTINGS_PATH,   \
+        (x),                     \
+        sizeof(DesktopSettings), \
+        DESKTOP_SETTINGS_MAGIC,  \
+        DESKTOP_SETTINGS_VER)
+
+#define LOAD_DESKTOP_SETTINGS(x) \
+    saved_struct_load(           \
+        DESKTOP_SETTINGS_PATH,   \
+        (x),                     \
+        sizeof(DesktopSettings), \
+        DESKTOP_SETTINGS_MAGIC,  \
+        DESKTOP_SETTINGS_VER)
+
 typedef struct {
     uint8_t length;
     uint8_t data[PIN_MAX_LENGTH];
 } PinCode;
 
 typedef struct {
-    uint8_t version;
     uint16_t favorite;
-
     PinCode pincode;
-    bool locked;
 } DesktopSettings;
-
-bool desktop_settings_load(DesktopSettings* desktop_settings);
-
-bool desktop_settings_save(DesktopSettings* desktop_settings);

applications/desktop/desktop_settings/desktop_settings_app.c

@@ -15,9 +15,6 @@ static bool desktop_settings_back_event_callback(void* context) {
 DesktopSettingsApp* desktop_settings_app_alloc() {
     DesktopSettingsApp* app = furi_alloc(sizeof(DesktopSettingsApp));
 
-    app->settings.version = DESKTOP_SETTINGS_VER;
-    desktop_settings_load(&app->settings);
-
     app->gui = furi_record_open("gui");
     app->view_dispatcher = view_dispatcher_alloc();
     app->scene_manager = scene_manager_alloc(&desktop_settings_scene_handlers, app);
@@ -62,8 +59,8 @@ void desktop_settings_app_free(DesktopSettingsApp* app) {
 
 extern int32_t desktop_settings_app(void* p) {
     DesktopSettingsApp* app = desktop_settings_app_alloc();
+    LOAD_DESKTOP_SETTINGS(&app->settings);
     view_dispatcher_run(app->view_dispatcher);
-    desktop_settings_save(&app->settings);
     desktop_settings_app_free(app);
     return 0;
 }

applications/desktop/desktop_settings/scenes/desktop_settings_scene_favorite.c

@@ -1,5 +1,6 @@
 #include "../desktop_settings_app.h"
 #include "applications.h"
+#include "desktop/desktop_settings/desktop_settings.h"
 
 static void desktop_settings_scene_favorite_submenu_callback(void* context, uint32_t index) {
     DesktopSettingsApp* app = context;
@@ -43,5 +44,6 @@ bool desktop_settings_scene_favorite_on_event(void* context, SceneManagerEvent e
 
 void desktop_settings_scene_favorite_on_exit(void* context) {
     DesktopSettingsApp* app = context;
+    SAVE_DESKTOP_SETTINGS(&app->settings);
     submenu_clean(app->submenu);
 }

applications/desktop/desktop_settings/scenes/desktop_settings_scene_pincode_input.c

@@ -1,4 +1,5 @@
 #include "../desktop_settings_app.h"
+#include "desktop/desktop_settings/desktop_settings.h"
 
 #define SCENE_EXIT_EVENT (0U)
 
@@ -57,6 +58,7 @@ bool desktop_settings_scene_pincode_input_on_event(void* context, SceneManagerEv
 
 void desktop_settings_scene_pincode_input_on_exit(void* context) {
     DesktopSettingsApp* app = context;
+    SAVE_DESKTOP_SETTINGS(&app->settings);
     code_input_set_result_callback(app->code_input, NULL, NULL, NULL, NULL, NULL, 0);
     code_input_set_header_text(app->code_input, "");
 }

applications/desktop/scenes/desktop_scene_lock_menu.c

@@ -1,5 +1,8 @@
 #include "../desktop_i.h"
 #include "../views/desktop_lock_menu.h"
+#include <toolbox/saved_struct.h>
+#include <stdbool.h>
+#include <furi-hal-lock.h>
 
 void desktop_scene_lock_menu_callback(DesktopLockMenuEvent event, void* context) {
     Desktop* desktop = (Desktop*)context;
@@ -9,7 +12,7 @@ void desktop_scene_lock_menu_callback(DesktopLockMenuEvent event, void* context)
 void desktop_scene_lock_menu_on_enter(void* context) {
     Desktop* desktop = (Desktop*)context;
 
-    desktop_settings_load(&desktop->settings);
+    LOAD_DESKTOP_SETTINGS(&desktop->settings);
 
     desktop_lock_menu_set_callback(desktop->lock_menu, desktop_scene_lock_menu_callback, desktop);
     desktop_lock_menu_pin_set(desktop->lock_menu, desktop->settings.pincode.length > 0);
@@ -29,10 +32,9 @@ bool desktop_scene_lock_menu_on_event(void* context, SceneManagerEvent event) {
             consumed = true;
             break;
         case DesktopLockMenuEventPinLock:
-
             if(desktop->settings.pincode.length > 0) {
-                desktop->settings.locked = true;
-                desktop_settings_save(&desktop->settings);
+                furi_hal_lock_set(true);
+                furi_hal_usb_disable();
                 scene_manager_set_scene_state(
                     desktop->scene_manager, DesktopSceneLocked, DesktopLockedWithPin);
                 scene_manager_next_scene(desktop->scene_manager, DesktopSceneLocked);
@@ -43,10 +45,10 @@ bool desktop_scene_lock_menu_on_event(void* context, SceneManagerEvent event) {
             consumed = true;
             break;
         case DesktopLockMenuEventExit:
-            scene_manager_next_scene(desktop->scene_manager, DesktopSceneMain);
+            scene_manager_search_and_switch_to_previous_scene(
+                desktop->scene_manager, DesktopSceneMain);
             consumed = true;
             break;
-
         default:
             break;
         }

applications/desktop/scenes/desktop_scene_locked.c

@@ -1,5 +1,6 @@
 #include "../desktop_i.h"
 #include "../views/desktop_locked.h"
+#include <furi-hal-lock.h>
 
 void desktop_scene_locked_callback(DesktopLockedEvent event, void* context) {
     Desktop* desktop = (Desktop*)context;
@@ -40,8 +41,8 @@ static bool desktop_scene_locked_check_pin(Desktop* desktop, DesktopMainEvent ev
 
     if(match) {
         desktop->pincode_buffer.length = 0;
-        desktop->settings.locked = false;
-        desktop_settings_save(&desktop->settings);
+        furi_hal_usb_enable();
+        furi_hal_lock_set(false);
         desktop_main_unlocked(desktop->main_view);
     }
 

applications/desktop/scenes/desktop_scene_main.c

@@ -34,8 +34,6 @@ void desktop_scene_main_on_enter(void* context) {
     desktop_main_set_callback(main_view, desktop_scene_main_callback, desktop);
     view_port_enabled_set(desktop->lock_viewport, false);
 
-    desktop_settings_load(&desktop->settings);
-
     if(scene_manager_get_scene_state(desktop->scene_manager, DesktopSceneMain) ==
        DesktopMainEventUnlocked) {
         desktop_main_unlocked(desktop->main_view);
@@ -72,7 +70,7 @@ bool desktop_scene_main_on_event(void* context, SceneManagerEvent event) {
             break;
 
         case DesktopMainEventOpenFavorite:
-            desktop_settings_load(&desktop->settings);
+            LOAD_DESKTOP_SETTINGS(&desktop->settings);
             desktop_switch_to_app(desktop, &FLIPPER_APPS[desktop->settings.favorite]);
             consumed = true;
             break;

applications/desktop/scenes/desktop_scene_pinsetup.c

@@ -4,7 +4,6 @@
 
 void desktop_scene_ok_callback(void* context) {
     Desktop* app = context;
-    desktop_settings_save(&app->settings);
     view_dispatcher_send_custom_event(app->view_dispatcher, SCENE_EXIT_EVENT);
 }
 
@@ -45,6 +44,7 @@ bool desktop_scene_pinsetup_on_event(void* context, SceneManagerEvent event) {
 
 void desktop_scene_pinsetup_on_exit(void* context) {
     Desktop* app = context;
+    SAVE_DESKTOP_SETTINGS(&app->settings);
     code_input_set_result_callback(app->code_input, NULL, NULL, NULL, NULL, NULL, 0);
     code_input_set_header_text(app->code_input, "");
 }

applications/desktop/views/desktop_lock_menu.h

@@ -10,7 +10,6 @@
 
 typedef enum {
     DesktopLockMenuEventLock,
-    DesktopLockMenuEventUnlock,
     DesktopLockMenuEventPinLock,
     DesktopLockMenuEventExit,
 } DesktopLockMenuEvent;

applications/dolphin/dolphin.c

@@ -81,12 +81,7 @@ static void dolphin_check_butthurt(DolphinState* state) {
     furi_assert(state);
     float diff_time = difftime(dolphin_state_get_timestamp(state), dolphin_state_timestamp());
 
-#if 0
-    FURI_LOG_I("dolphin-state", "Butthurt check, time since deed %.0f", fabs(diff_time));
-#endif
-
     if((fabs(diff_time)) > DOLPHIN_TIMEGATE) {
-        // increase butthurt
         FURI_LOG_I("dolphin-state", "Increasing butthurt");
         dolphin_state_butthurted(state);
     }

applications/dolphin/helpers/dolphin_state.c

@@ -2,20 +2,13 @@
 #include <storage/storage.h>
 #include <furi.h>
 #include <math.h>
+#include <toolbox/saved_struct.h>
 
-#define DOLPHIN_STORE_KEY "/int/dolphin.state"
+#define DOLPHIN_STORE_PATH "/int/dolphin.state"
 #define DOLPHIN_STORE_HEADER_MAGIC 0xD0
 #define DOLPHIN_STORE_HEADER_VERSION 0x01
 #define DOLPHIN_LVL_THRESHOLD 20.0f
 
-typedef struct {
-    uint8_t magic;
-    uint8_t version;
-    uint8_t checksum;
-    uint8_t flags;
-    uint32_t timestamp;
-} DolphinStoreHeader;
-
 typedef struct {
     uint32_t limit_ibutton;
     uint32_t limit_nfc;
@@ -28,148 +21,42 @@ typedef struct {
     uint64_t timestamp;
 } DolphinStoreData;
 
-typedef struct {
-    DolphinStoreHeader header;
-    DolphinStoreData data;
-} DolphinStore;
-
 struct DolphinState {
-    Storage* fs_api;
     DolphinStoreData data;
     bool dirty;
 };
 
 DolphinState* dolphin_state_alloc() {
-    DolphinState* dolphin_state = furi_alloc(sizeof(DolphinState));
-    dolphin_state->fs_api = furi_record_open("storage");
-    return dolphin_state;
+    return furi_alloc(sizeof(DolphinState));
 }
 
 void dolphin_state_free(DolphinState* dolphin_state) {
-    furi_record_close("storage");
     free(dolphin_state);
 }
 
 bool dolphin_state_save(DolphinState* dolphin_state) {
-    if(!dolphin_state->dirty) {
-        return true;
-    }
-
-    FURI_LOG_I("dolphin-state", "State is dirty, saving to \"%s\"", DOLPHIN_STORE_KEY);
-    DolphinStore store;
-    // Calculate checksum
-    uint8_t* source = (uint8_t*)&dolphin_state->data;
-    uint8_t checksum = 0;
-    for(size_t i = 0; i < sizeof(DolphinStoreData); i++) {
-        checksum += source[i];
-    }
-    // Set header
-    store.header.magic = DOLPHIN_STORE_HEADER_MAGIC;
-    store.header.version = DOLPHIN_STORE_HEADER_VERSION;
-    store.header.checksum = checksum;
-    store.header.flags = 0;
-    store.header.timestamp = 0;
-    // Set data
-    store.data = dolphin_state->data;
-
-    // Store
-    File* file = storage_file_alloc(dolphin_state->fs_api);
-    bool save_result = storage_file_open(file, DOLPHIN_STORE_KEY, FSAM_WRITE, FSOM_CREATE_ALWAYS);
-
-    if(save_result) {
-        uint16_t bytes_count = storage_file_write(file, &store, sizeof(DolphinStore));
-
-        if(bytes_count != sizeof(DolphinStore)) {
-            save_result = false;
-        }
-    }
-
-    if(!save_result) {
-        FURI_LOG_E(
-            "dolphin-state",
-            "Save failed. Storage returned: %s",
-            storage_file_get_error_desc(file));
-    }
-
-    storage_file_close(file);
-    storage_file_free(file);
-
-    dolphin_state->dirty = !save_result;
-
-    FURI_LOG_I("dolphin-state", "Saved");
-
-    return save_result;
+    return saved_struct_save(
+        DOLPHIN_STORE_PATH,
+        &dolphin_state->data,
+        sizeof(DolphinStoreData),
+        DOLPHIN_STORE_HEADER_MAGIC,
+        DOLPHIN_STORE_HEADER_VERSION);
 }
 
 bool dolphin_state_load(DolphinState* dolphin_state) {
-    DolphinStore store;
-    // Read Dolphin State Store
-    FURI_LOG_I("dolphin-state", "Loading state from \"%s\"", DOLPHIN_STORE_KEY);
-
-    File* file = storage_file_alloc(dolphin_state->fs_api);
-    bool load_result = storage_file_open(file, DOLPHIN_STORE_KEY, FSAM_READ, FSOM_OPEN_EXISTING);
-    if(!load_result) {
-        FURI_LOG_E(
-            "dolphin-state",
-            "Load failed. Storage returned: %s",
-            storage_file_get_error_desc(file));
-    } else {
-        uint16_t bytes_count = storage_file_read(file, &store, sizeof(DolphinStore));
-
-        if(bytes_count != sizeof(DolphinStore)) {
-            load_result = false;
-        }
-    }
-
-    if(!load_result) {
-        FURI_LOG_E("dolphin-state", "DolphinStore size mismatch");
-    } else {
-        if(store.header.magic == DOLPHIN_STORE_HEADER_MAGIC &&
-           store.header.version == DOLPHIN_STORE_HEADER_VERSION) {
-            FURI_LOG_I(
-                "dolphin-state",
-                "Magic(%d) and Version(%d) match",
-                store.header.magic,
-                store.header.version);
-            uint8_t checksum = 0;
-            const uint8_t* source = (const uint8_t*)&store.data;
-            for(size_t i = 0; i < sizeof(DolphinStoreData); i++) {
-                checksum += source[i];
-            }
-
-            if(store.header.checksum == checksum) {
-                FURI_LOG_I("dolphin-state", "Checksum(%d) match", store.header.checksum);
-                dolphin_state->data = store.data;
-            } else {
-                FURI_LOG_E(
-                    "dolphin-state",
-                    "Checksum(%d != %d) mismatch",
-                    store.header.checksum,
-                    checksum);
-                load_result = false;
-            }
-        } else {
-            FURI_LOG_E(
-                "dolphin-state",
-                "Magic(%d != %d) or Version(%d != %d) mismatch",
-                store.header.magic,
-                DOLPHIN_STORE_HEADER_MAGIC,
-                store.header.version,
-                DOLPHIN_STORE_HEADER_VERSION);
-            load_result = false;
-        }
+    bool loaded = saved_struct_load(
+        DOLPHIN_STORE_PATH,
+        &dolphin_state->data,
+        sizeof(DolphinStoreData),
+        DOLPHIN_STORE_HEADER_MAGIC,
+        DOLPHIN_STORE_HEADER_VERSION);
+    if(!loaded) {
+        FURI_LOG_W("dolphin-state", "Reset dolphin-state");
+        memset(dolphin_state, 0, sizeof(*dolphin_state));
+        dolphin_state_save(dolphin_state);
     }
 
-    storage_file_close(file);
-    storage_file_free(file);
-
-    dolphin_state->dirty = !load_result;
-
-    return load_result;
-}
-
-void dolphin_state_clear(DolphinState* dolphin_state) {
-    memset(&dolphin_state->data, 0, sizeof(DolphinStoreData));
+    return true;
 }
 
 uint64_t dolphin_state_timestamp() {
@@ -229,4 +116,4 @@ uint32_t dolphin_state_get_level(uint32_t icounter) {
 
 uint32_t dolphin_state_xp_to_levelup(uint32_t icounter, uint32_t level, bool remaining) {
     return (DOLPHIN_LVL_THRESHOLD * level * (level + 1) / 2) - (remaining ? icounter : 0);
-}
+}

firmware/targets/f6/furi-hal/furi-hal-lock.c

@@ -0,0 +1,17 @@
+#include "furi-hal-lock.h"
+#include <stm32wbxx_ll_rtc.h>
+
+#define FLIPPER_LOCKED_VALUE 0x5432FAFA
+
+bool furi_hal_lock_get() {
+    return FLIPPER_LOCKED_VALUE == LL_RTC_BAK_GetRegister(RTC, LL_RTC_BKP_DR3);
+}
+
+void furi_hal_lock_set(bool locked) {
+    if (locked) {
+        LL_RTC_BAK_SetRegister(RTC, LL_RTC_BKP_DR3, FLIPPER_LOCKED_VALUE);
+    } else {
+        LL_RTC_BAK_SetRegister(RTC, LL_RTC_BKP_DR3, 0);
+    }
+}
+

firmware/targets/f7/furi-hal/furi-hal-lock.c

@@ -0,0 +1,17 @@
+#include "furi-hal-lock.h"
+#include <stm32wbxx_ll_rtc.h>
+
+#define FLIPPER_LOCKED_VALUE 0x5432FAFA
+
+bool furi_hal_lock_get() {
+    return FLIPPER_LOCKED_VALUE == LL_RTC_BAK_GetRegister(RTC, LL_RTC_BKP_DR3);
+}
+
+void furi_hal_lock_set(bool locked) {
+    if (locked) {
+        LL_RTC_BAK_SetRegister(RTC, LL_RTC_BKP_DR3, FLIPPER_LOCKED_VALUE);
+    } else {
+        LL_RTC_BAK_SetRegister(RTC, LL_RTC_BKP_DR3, 0);
+    }
+}
+

firmware/targets/furi-hal-include/furi-hal-lock.h

@@ -0,0 +1,5 @@
+#pragma once
+#include <stdbool.h>
+
+bool furi_hal_lock_get();
+void furi_hal_lock_set(bool locked);

lib/toolbox/saved_struct.c

@@ -0,0 +1,149 @@
+#include "saved_struct.h"
+#include <furi.h>
+#include <stdint.h>
+#include <storage/storage.h>
+
+#define SAVED_STRUCT_TAG    "SAVED_STRUCT"
+
+typedef struct {
+    uint8_t magic;
+    uint8_t version;
+    uint8_t checksum;
+    uint8_t flags;
+    uint32_t timestamp;
+} SavedStructHeader;
+
+bool saved_struct_save(const char* path,
+                       void* data,
+                       size_t size,
+                       uint8_t magic,
+                       uint8_t version) {
+    furi_assert(path);
+    furi_assert(data);
+    furi_assert(size);
+    SavedStructHeader header;
+
+    FURI_LOG_I(SAVED_STRUCT_TAG, "Saving \"%s\"", path);
+
+    // Store
+    Storage* storage = furi_record_open("storage");
+    File* file = storage_file_alloc(storage);
+    bool result = true;
+    bool saved = storage_file_open(file, path, FSAM_WRITE, FSOM_CREATE_ALWAYS);
+    if(!saved) {
+        FURI_LOG_E(
+            SAVED_STRUCT_TAG,
+            "Open failed \"%s\". Error: \'%s\'",
+            path,
+            storage_file_get_error_desc(file));
+        result = false;
+    }
+
+    if(result) {
+        // Calculate checksum
+        uint8_t checksum = 0;
+        uint8_t* source = data;
+        for(size_t i = 0; i < size; i++) {
+            checksum += source[i];
+        }
+        // Set header
+        header.magic = magic;
+        header.version = version;
+        header.checksum = checksum;
+        header.flags = 0;
+        header.timestamp = 0;
+
+        uint16_t bytes_count = storage_file_write(file, &header, sizeof(header));
+        bytes_count += storage_file_write(file, data, size);
+
+        if(bytes_count != (size + sizeof(header))) {
+            FURI_LOG_E(
+                SAVED_STRUCT_TAG,
+                "Write failed \"%s\". Error: \'%s\'",
+                path,
+                storage_file_get_error_desc(file));
+            result = false;
+        }
+    }
+
+    storage_file_close(file);
+    storage_file_free(file);
+    furi_record_close("storage");
+    return result;
+}
+
+bool saved_struct_load(const char* path,
+                       void* data,
+                       size_t size,
+                       uint8_t magic,
+                       uint8_t version) {
+    FURI_LOG_I(SAVED_STRUCT_TAG, "Loading \"%s\"", path);
+
+    SavedStructHeader header;
+
+    uint8_t* data_read = furi_alloc(size);
+    Storage* storage = furi_record_open("storage");
+    File* file = storage_file_alloc(storage);
+    bool result = true;
+    bool loaded = storage_file_open(file, path, FSAM_READ, FSOM_OPEN_EXISTING);
+    if (!loaded) {
+        FURI_LOG_E(
+            SAVED_STRUCT_TAG,
+            "Failed to read \"%s\". Error: %s",
+            path,
+            storage_file_get_error_desc(file));
+        result = false;
+    }
+
+    if (result) {
+        uint16_t bytes_count = storage_file_read(file, &header, sizeof(SavedStructHeader));
+        bytes_count += storage_file_read(file, data_read, size);
+
+        if(bytes_count != (sizeof(SavedStructHeader) + size)) {
+            FURI_LOG_E(SAVED_STRUCT_TAG, "Size mismatch of file \"%s\"", path);
+            result = false;
+        }
+    }
+
+    if(result && (header.magic != magic || header.version != version)) {
+        FURI_LOG_E(
+            SAVED_STRUCT_TAG,
+            "Magic(%d != %d) or Version(%d != %d) mismatch of file \"%s\"",
+            header.magic,
+            magic,
+            header.version,
+            version,
+            path);
+        result = false;
+    }
+
+    if(result) {
+        uint8_t checksum = 0;
+        const uint8_t* source = (const uint8_t*)data_read;
+        for(size_t i = 0; i < size; i++) {
+            checksum += source[i];
+        }
+
+        if(header.checksum != checksum) {
+            FURI_LOG_E(
+                SAVED_STRUCT_TAG,
+                "Checksum(%d != %d) mismatch of file \"%s\"",
+                header.checksum,
+                checksum,
+                path);
+            result = false;
+        }
+    }
+
+    if (result) {
+        memcpy(data, data_read, size);
+    }
+
+    storage_file_close(file);
+    storage_file_free(file);
+    furi_record_close("storage");
+    free(data_read);
+
+    return result;
+}
+

lib/toolbox/saved_struct.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+bool saved_struct_load(const char* path,
+                       void* data,
+                       size_t size,
+                       uint8_t magic,
+                       uint8_t version);
+
+bool saved_struct_save(const char* path,
+                       void* data,
+                       size_t size,
+                       uint8_t magic,
+                       uint8_t version);
+