Make lcd_bootscreen common to both

Marlin/Marlin_main.cpp

@@ -13034,11 +13034,16 @@ void setup() {
   #endif
 
   lcd_init();
+
   #if ENABLED(SHOW_BOOTSCREEN)
-    #if ENABLED(DOGLCD)
-      safe_delay(BOOTSCREEN_TIMEOUT);
+    #if ENABLED(DOGLCD)                           // On DOGM the first bootscreen is already drawn
+      #if ENABLED(SHOW_CUSTOM_BOOTSCREEN)
+        safe_delay(CUSTOM_BOOTSCREEN_TIMEOUT);    // Custom boot screen pause
+        lcd_bootscreen();                         // Show Marlin boot screen
+      #endif
+      safe_delay(BOOTSCREEN_TIMEOUT);             // Pause
     #elif ENABLED(ULTRA_LCD)
-      bootscreen();
+      lcd_bootscreen();
       #if DISABLED(SDSUPPORT)
         lcd_init();
       #endif

Marlin/ultralcd.h

@@ -64,8 +64,10 @@
   #if ENABLED(DOGLCD)
     extern uint16_t lcd_contrast;
     void set_lcd_contrast(const uint16_t value);
-  #elif ENABLED(SHOW_BOOTSCREEN)
-    void bootscreen();
+  #endif
+
+  #if ENABLED(SHOW_BOOTSCREEN)
+    void lcd_bootscreen();
   #endif
 
   #define LCD_UPDATE_INTERVAL 100

Marlin/ultralcd_impl_DOGM.h

@@ -256,38 +256,11 @@ void lcd_printPGM_utf(const char *str, uint8_t n=LCD_WIDTH) {
   while (n && (c = pgm_read_byte(str))) n -= charset_mapper(c), ++str;
 }
 
-// Initialize or re-initialize the LCD
-static void lcd_implementation_init() {
-
-  #if PIN_EXISTS(LCD_BACKLIGHT) // Enable LCD backlight
-    OUT_WRITE(LCD_BACKLIGHT_PIN, HIGH);
-  #endif
-
-  #if PIN_EXISTS(LCD_RESET)
-    OUT_WRITE(LCD_RESET_PIN, LOW); // perform a clean hardware reset
-    _delay_ms(5);
-    OUT_WRITE(LCD_RESET_PIN, HIGH);
-    _delay_ms(5); // delay to allow the display to initalize
-    u8g.begin(); // re-initialize the display
-  #endif
-
-  #if DISABLED(MINIPANEL) // setContrast not working for Mini Panel
-    u8g.setContrast(lcd_contrast);
-  #endif
-
-  #if ENABLED(LCD_SCREEN_ROT_90)
-    u8g.setRot90();   // Rotate screen by 90°
-  #elif ENABLED(LCD_SCREEN_ROT_180)
-    u8g.setRot180();  // Rotate screen by 180°
-  #elif ENABLED(LCD_SCREEN_ROT_270)
-    u8g.setRot270();  // Rotate screen by 270°
-  #endif
-
-  #if ENABLED(SHOW_BOOTSCREEN)
-    static bool show_bootscreen = true;
+#if ENABLED(SHOW_BOOTSCREEN)
 
   #if ENABLED(SHOW_CUSTOM_BOOTSCREEN)
-      if (show_bootscreen) {
+
+    void lcd_custom_bootscreen() {
       u8g.firstPage();
       do {
         u8g.drawBitmapP(
@@ -295,11 +268,16 @@ static void lcd_implementation_init() {
           ( 64 - (CUSTOM_BOOTSCREEN_BMPHEIGHT)) /2,
           CEILING(CUSTOM_BOOTSCREEN_BMPWIDTH, 8), CUSTOM_BOOTSCREEN_BMPHEIGHT, custom_start_bmp);
       } while (u8g.nextPage());
-        safe_delay(CUSTOM_BOOTSCREEN_TIMEOUT);
     }
+
   #endif // SHOW_CUSTOM_BOOTSCREEN
 
-    const uint8_t offx = (u8g.getWidth() - (START_BMPWIDTH)) / 2;
+  void lcd_bootscreen() {
+
+    static bool show_bootscreen = true;
+
+    if (show_bootscreen) {
+      show_bootscreen = false;
 
       #if ENABLED(START_BMPHIGH)
         constexpr uint8_t offy = 0;
@@ -307,9 +285,9 @@ static void lcd_implementation_init() {
         constexpr uint8_t offy = DOG_CHAR_HEIGHT;
       #endif
 
-    const uint8_t txt1X = (u8g.getWidth() - (sizeof(STRING_SPLASH_LINE1) - 1) * (DOG_CHAR_WIDTH)) / 2;
+      const uint8_t offx = (u8g.getWidth() - (START_BMPWIDTH)) / 2,
+                    txt1X = (u8g.getWidth() - (sizeof(STRING_SPLASH_LINE1) - 1) * (DOG_CHAR_WIDTH)) / 2;
 
-    if (show_bootscreen) {
       u8g.firstPage();
       do {
         u8g.drawBitmapP(offx, offy, START_BMPBYTEWIDTH, START_BMPHEIGHT, start_bmp);
@@ -323,10 +301,44 @@ static void lcd_implementation_init() {
         #endif
       } while (u8g.nextPage());
     }
+  }
 
-    show_bootscreen = false;
+#endif // SHOW_BOOTSCREEN
+
+// Initialize or re-initialize the LCD
+static void lcd_implementation_init() {
+
+  #if PIN_EXISTS(LCD_BACKLIGHT) // Enable LCD backlight
+    OUT_WRITE(LCD_BACKLIGHT_PIN, HIGH);
+  #endif
+
+  #if PIN_EXISTS(LCD_RESET)
+    OUT_WRITE(LCD_RESET_PIN, LOW); // perform a clean hardware reset
+    _delay_ms(5);
+    OUT_WRITE(LCD_RESET_PIN, HIGH);
+    _delay_ms(5); // delay to allow the display to initalize
+    u8g.begin(); // re-initialize the display
+  #endif
+
+  #if DISABLED(MINIPANEL) // setContrast not working for Mini Panel
+    u8g.setContrast(lcd_contrast);
+  #endif
+
+  #if ENABLED(LCD_SCREEN_ROT_90)
+    u8g.setRot90();   // Rotate screen by 90°
+  #elif ENABLED(LCD_SCREEN_ROT_180)
+    u8g.setRot180();  // Rotate screen by 180°
+  #elif ENABLED(LCD_SCREEN_ROT_270)
+    u8g.setRot270();  // Rotate screen by 270°
+  #endif
 
-  #endif // SHOW_BOOTSCREEN
+  #if ENABLED(SHOW_BOOTSCREEN)
+    #if ENABLED(SHOW_CUSTOM_BOOTSCREEN)
+      lcd_custom_bootscreen();
+    #else
+      lcd_bootscreen();
+    #endif
+  #endif
 }
 
 // The kill screen is displayed for unrecoverable conditions

Marlin/ultralcd_impl_HD44780.h

@@ -443,7 +443,7 @@ void lcd_printPGM_utf(const char *str, uint8_t n=LCD_WIDTH) {
     lcd.setCursor(indent, 2); lcd.write('\x02'); lcd_printPGM(PSTR( "------" ));  lcd.write('\x03');
   }
 
-  void bootscreen() {
+  void lcd_bootscreen() {
     const static PROGMEM byte corner[4][8] = { {
       B00000,
       B00000,