Moving to offscreen Driver

KH-clock.service

@@ -8,8 +8,8 @@ Type=simple
 User=pi
 WorkingDirectory=/opt/KH_Clock
 
-# Tell SDL to render via KMS/DRM (required on Le Potato and similar ARM boards)
+# SDL renders offscreen; pixels are blit directly to /dev/fb0 (Amlogic kmsdrm is unsupported)
-Environment=SDL_VIDEODRIVER=kmsdrm
+Environment=SDL_VIDEODRIVER=offscreen
 
 # Disable console blanking so the TV stays on
 ExecStartPre=/bin/sh -c 'echo -ne "\033[9;0]" > /dev/tty1'

display.py

@@ -1,3 +1,4 @@
+import mmap
 import os
 import threading
 import time
@@ -147,7 +148,9 @@ class DisplayThread(threading.Thread):
         if self.dev_mode:
             os.environ.setdefault("SDL_VIDEODRIVER", "x11")
         else:
-            os.environ["SDL_VIDEODRIVER"] = "kmsdrm"
+            # SDL kmsdrm is incompatible with the Amlogic MESON DRM driver.
+            # Use offscreen rendering and blit pixels directly to /dev/fb0.
+            os.environ["SDL_VIDEODRIVER"] = "offscreen"
 
         try:
             pygame.init()
@@ -166,6 +169,19 @@ class DisplayThread(threading.Thread):
         clock = pygame.time.Clock()
         screen_w, screen_h = screen.get_size()
 
+        # Open /dev/fb0 for direct pixel writes (framebuffer mode only)
+        fb0_mmap = None
+        fb0_file = None
+        if not self.dev_mode:
+            try:
+                bpp = int(Path("/sys/class/graphics/fb0/bits_per_pixel").read_text())
+                fb0_file = open("/dev/fb0", "rb+")
+                fb0_mmap = mmap.mmap(fb0_file.fileno(), screen_w * screen_h * (bpp // 8))
+            except Exception as e:
+                print(f"[display] Failed to open /dev/fb0: {e}")
+                pygame.quit()
+                return
+
         clock_font_path = _find_font(self.config.clock_font_path, _CLOCK_FONT_CANDIDATES)
         msg_font_path = _find_font(self.config.message_font_path, _MESSAGE_FONT_CANDIDATES)
 
@@ -205,9 +221,17 @@ class DisplayThread(threading.Thread):
                 last_msg_text = None
                 self._draw_clock(screen, clock_font, screen_w, screen_h)
 
-            pygame.display.flip()
+            if fb0_mmap is not None:
+                fb0_mmap.seek(0)
+                fb0_mmap.write(pygame.image.tostring(screen, "BGRA"))
+            else:
+                pygame.display.flip()
             clock.tick(self.config.fps)
 
+        if fb0_mmap:
+            fb0_mmap.close()
+        if fb0_file:
+            fb0_file.close()
         pygame.quit()
 
     def _create_surface(self) -> pygame.Surface:
@@ -218,10 +242,10 @@ class DisplayThread(threading.Thread):
             pygame.display.set_caption("KH Clock [DEV]")
             return surface
 
-        flags = pygame.FULLSCREEN | pygame.NOFRAME
+        # Read actual framebuffer dimensions from sysfs
-        if self.config.width and self.config.height:
+        size_str = Path("/sys/class/graphics/fb0/virtual_size").read_text().strip()
-            return pygame.display.set_mode((self.config.width, self.config.height), flags)
+        w, h = map(int, size_str.split(","))
-        return pygame.display.set_mode((0, 0), flags)
+        return pygame.display.set_mode((w, h))
 
     @staticmethod
     def _draw_clock(