Add support for fourmi display via custom DRM kernel driver flake

Signed-off-by: Mel <mel@rnrd.eu>

1 files changed, 9 insertions, 0 deletions

diff --git a/modules/klipperscreen.nix b/modules/klipperscreen.nix
index 9235360..d4d9bfa 100644
--- a/modules/klipperscreen.nix
+++ b/modules/klipperscreen.nix
@@ -29,6 +29,15 @@ in
     environment = {
       # don't fail with no devices found.
       "WLR_LIBINPUT_NO_DEVICES" = "1";
+
+      # render onto the SPI panel (see modules/hardware/ili9486.nix), not
+      # the firmware/HDMI framebuffer. by-path is stable across boots,
+      # unlike cardN numbering.
+      "WLR_DRM_DEVICES" = "/dev/dri/by-path/platform-fe204000.spi-cs-0-card";
+
+      # the SPI panel has no GPU render node, so GLES cannot initialize;
+      # software rendering into dumb buffers works fine at 480x320.
+      "WLR_RENDERER" = "pixman";
     };
     user = "klipper";
   };