Enable custom wallpaper.

builder/stage4/04-pisdr-system/01-run.sh

@@ -2,4 +2,9 @@ install -m 755 shortcut/gnuradio.desktop "${ROOTFS_DIR}/home/${FIRST_USER_NAME}/
 install -m 755 shortcut/gqrx.desktop "${ROOTFS_DIR}/home/${FIRST_USER_NAME}/Desktop"
 install -m 755 shortcut/sdrangel.desktop "${ROOTFS_DIR}/home/${FIRST_USER_NAME}/Desktop"
 
-install -m 755 wallpaper/donald-giannatti-vla.jpg "${ROOTFS_DIR}/usr/share/rpd-wallpaper/"
+install -m 755 wallpaper/donald-giannatti-vla.jpg "${ROOTFS_DIR}/usr/share/rpd-wallpaper/"
+
+on_chroot << EOF
+export DISPLAY=:0.0
+pcmanfm --set-wallpaper ${ROOTFS_DIR}/usr/share/rpd-wallpaper/donald-giannatti-vla.jpg
+EOF