refactor: refactored app settings to reduce storage usage (#12)

src/globals.c

@@ -1,5 +1,8 @@
 #include "globals.h"
 
+// The settings, stored in NVRAM.
+const internal_storage_t N_storage_real;
+
 uint8_t G_io_seproxyhal_spi_buffer[IO_SEPROXYHAL_BUFFER_SIZE_B];
 ux_state_t G_ux;
 bolos_ux_params_t G_ux_params;

src/globals.h

@@ -4,8 +4,12 @@
 
 #include "ux.h"
 #include "types.h"
-
 #include "io.h"
+#include "settings.h"
+/**
+ * The settings, stored in NVRAM. Initializer is ignored by ledger.
+ */
+extern const internal_storage_t N_storage_real;
 
 /**
  * Global buffer for interactions between SE and MCU.

src/handler/get_app_configuration.c

@@ -28,7 +28,7 @@
 #include "../sw.h"
 #include "../types.h"
 #include "common/buffer.h"
-#include "../app_mode.h"
+#include "../settings.h"
 
 int handler_get_app_configuration() {
     PRINTF("handler_get_app_configuration invoked\n");
@@ -44,7 +44,7 @@ int handler_get_app_configuration() {
     return io_send_response(
         &(const buffer_t){.ptr =
                               (uint8_t[APP_CONFIGURATION_SIZE + APP_VERSION_SIZE]){
-                                  (uint8_t) app_mode_hash_signing_enabled(),
+                                  (uint8_t) HAS_SETTING(S_HASH_SIGNING_ENABLED),
                                   (uint8_t) MAJOR_VERSION,
                                   (uint8_t) MINOR_VERSION,
                                   (uint8_t) PATCH_VERSION},

src/handler/sign_transaction_hash.c

@@ -17,14 +17,14 @@
 
 #include "handler.h"
 #include "../globals.h"
-#include "../app_mode.h"
+#include "../settings.h"
 #include "../sw.h"
 #include "../crypto.h"
 #include "../ui/ui.h"
 
 int handler_sign_tx_hash(buffer_t *cdata) {
     PRINTF("handler_sign_tx_hash invoked\n");
-    if (!app_mode_hash_signing_enabled()) {
+    if (!HAS_SETTING(S_HASH_SIGNING_ENABLED)) {
         return io_send_sw(SW_TX_HASH_SIGNING_MODE_NOT_ENABLED);
     }
     explicit_bzero(&G_context, sizeof(G_context));

src/main.c

@@ -110,7 +110,14 @@ void standalone_app_main() {
             TRY {
                 io_seproxyhal_init();
 
+                if (!HAS_SETTING(S_INITIALIZED)) {
+                    internal_storage_t storage = 0x00;
+                    storage |= 0x80;
+                    nvm_write((void *) &N_settings, (void *) &storage, sizeof(internal_storage_t));
+                }
+
 #ifdef TARGET_NANOX
+                // grab the current plane mode setting
                 G_io_app.plane_mode = os_setting_get(OS_SETTING_PLANEMODE, NULL, 0);
 #endif  // TARGET_NANOX
 

src/settings.h

@@ -0,0 +1,25 @@
+#pragma once
+
+#include <stdint.h>
+
+typedef uint8_t internal_storage_t;
+
+#define N_settings (*(volatile internal_storage_t *) PIC(&N_storage_real))
+
+// flip a bit k = 0 to 7 for u8
+#define _FLIP_BIT(n, k) (((n) ^ (1 << (k))))
+
+// toggle a setting item
+#define SETTING_TOGGLE(_set)                                                                   \
+    do {                                                                                       \
+        internal_storage_t _temp_settings = _FLIP_BIT(N_settings, _set);                       \
+        nvm_write((void *) &N_settings, (void *) &_temp_settings, sizeof(internal_storage_t)); \
+    } while (0)
+
+// check a setting item
+#define HAS_SETTING(k) ((N_settings & (1 << (k))) >> (k))
+
+#define S_HASH_SIGNING_ENABLED     0
+#define S_SEQUENCE_DISPLAY_ENABLED 1
+
+#define S_INITIALIZED 7

src/types.h

@@ -17,7 +17,7 @@
 #define APP_VERSION_SIZE 3
 
 /**
- * Length of app_mode_persistent_t.hash_signing_enabled
+ * Length of hash_signing_enabled
  */
 #define APP_CONFIGURATION_SIZE 1
 

src/ui/ui_menu.c

@@ -17,7 +17,7 @@
 
 #include "ui.h"
 #include "globals.h"
-#include "app_mode.h"
+#include "settings.h"
 
 void ui_idle(void);
 void display_settings(const ux_flow_step_t* const start_step);
@@ -88,12 +88,12 @@ void ui_idle(void) {
 
 void display_settings(const ux_flow_step_t* const start_step) {
     strlcpy(G_ui_detail_value,
-            (app_mode_hash_signing_enabled() ? "Enabled" : "NOT Enabled"),
+            (HAS_SETTING(S_HASH_SIGNING_ENABLED) ? "Enabled" : "NOT Enabled"),
             DETAIL_VALUE_MAX_LENGTH);
     ux_flow_init(0, ux_settings_flow, start_step);
 }
 
 void switch_settings_hash_signing() {
-    app_mode_change_hash_signing_setting();
+    SETTING_TOGGLE(S_HASH_SIGNING_ENABLED);
     display_settings(&ux_settings_hash_signing_step);
 }