Disable normal mode when flash is invalid

src/main.c

@@ -78,6 +78,8 @@ int main_handler(void) {
     btn2_was_pressed = button_pressed[1];
     btn1_was_pressed = button_pressed[0];
 
+    if (!flash_header_valid) return 1;
+
     return 0;
 }
 

src/menu.c

@@ -8,6 +8,7 @@
 #include "led.h"
 #include "ble.h"
 #include "button.h"
+#include "wang.h"
 
 #include "img/menu.xbm"
 
@@ -90,6 +91,14 @@ void menu_render(void) {
         }
     }
 
+    if (!flash_header_valid) {
+        for (int i = 0; i < 11; i++) {
+            for (int j = 0; j < 11; j++) {
+                PIX(i, j);
+            }
+        }
+    }
+
     render_xbm(buffer, display_screen);
     display_flip();
 }
@@ -97,7 +106,7 @@ void menu_render(void) {
 void menu_switch(void) {
     btn0_pressed = button_pressed[0];
     btn1_pressed = button_pressed[1];
-    menu_index = 0;
+    menu_index = flash_header_valid ? 0 : 1;
 
     menu_render();
 }
@@ -116,6 +125,7 @@ int menu_handler(void) {
 
     if (button_pressed[0] && !btn0_pressed && !button_pressed[1]) {
         menu_index = (menu_index + 1) % 3;
+        if (!flash_header_valid && !menu_index) menu_index = 1;
         menu_render();
         render_ticks = 0;
     }