Changes between Version 10 and Version 11 of qt

Timestamp:

12/17/2021 12:19:09 AM (3 years ago)

Author:

Tim Harvey

Comment:

explain EGLFS_KMS_CONFIG file format in more detail

qt

@@ -27 +27 @@
 EGLFS forces the first top-level window (either a QWidget or a QQuickView) to become full screen and chosen to be the root widget window into which all other top-level widgets are composited. There are a number of env variables that can be used to configure EGLFS: see https://doc.qt.io/qt-5/embedded-linux.html#eglfs
 
-To use the EGLFS platform plugin with a KMS/DRM backend you need to define a screen configuration file customized to your board and display.
-
-Examples:
- * 1080p HDMI:
+To use the EGLFS platform plugin with a KMS/DRM backend you need to define a screen configuration file customized to your board and display with some specific details:
+ * device: the display device node on your board (ie /dev/dri/card0)
+ * outputs: an array of outputs from /sys/class/drm
+
+Examples:
+ * Ventana IMX6QDL 1080p HDMI:
+  1. determine device/name/mode
+{{{#!bash
+root@focal-ventana:~# ls /sys/class/drm
+card0  card1  card1-HDMI-A-1  card1-LVDS-1  renderD128  version
+root@focal-ventana:~# cat /sys/class/drm/card1-HDMI-A-1/modes 
+1920x1080
+}}}
+   - Note there are two outputs 'card1-HDMI-A-1' and 'card1-LVDS-1' (card0 is unused) corresponding to to the /dev/dri/card1 device and the mode
+  1. create conf file:
 {{{#!bash
 cat << EOF > /etc/eglfs_hdmi.json
@@ -49 +60 @@
 }
 EOF
+}}}
+    - Note we disable LVDS-1 and configure HDMI-A-1 for our desired mode
+  1. export env vars:
+{{{#!bash
 export QT_QPA_EGLFS_KMS_CONFIG=/etc/eglfs_hdmi.json
 export QT_QPA_EGLFS_ALWAYS_SET_MODE=1
 export QT_QPA_PLATFORM=eglfs
 }}}
- * 1024x600 LVDS:
+ * Ventana IMX6QDL 1024x600 LVDS:
+  1. determine device/name/mode
+{{{#!bash
+root@focal-ventana:~# ls /sys/class/drm
+card0  card1  card1-HDMI-A-1  card1-LVDS-1  renderD128  version
+root@focal-ventana:~# cat /sys/class/drm/LVDS-1/modes 
+1024x600
+}}}
+   - Note there are two outputs 'card1-HDMI-A-1' and 'card1-LVDS-1' (card0 is unused) corresponding to to the /dev/dri/card1 device and the mode
+  1. create conf file:
 {{{#!bash
 cat << EOF > /etc/eglfs_lvds.json
@@ -72 +96 @@
 }
 EOF
+}}}
+    - Note we disable HDMI-A-1 and configure LVDS-1 for our desired mode
+  1. export env vars:
+{{{#!bash
 export QT_QPA_EGLFS_KMS_CONFIG=/etc/eglfs_lvds.json
 export QT_QPA_EGLFS_ALWAYS_SET_MODE=1