board/raspberrypi: use kernel Bluetooth mode

The default setting with miniuart-bt requires hciattach which is a
deprecated utility in BlueZ.  Setting the krnbt parameter switches to
the modern method of using serdev in the kernel removing the need for
any userspace configuration to enable the Bluetooth controller.

This is documented as applying to all Raspberry Pi variants so just
enable it globally.

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

diff --git a/board/raspberrypi/post-image.sh b/board/raspberrypi/post-image.sh
index 9dbd98ef9bd1fe275bc7760caf736717b743cef6..a6728c686e5677999eb6288959ce6030154749ad 100755 (executable)
--- a/board/raspberrypi/post-image.sh
+++ b/board/raspberrypi/post-image.sh
@@ -16,7 +16,7 @@ do
                        cat << __EOF__ >> "${BINARIES_DIR}/rpi-firmware/config.txt"
 
 # fixes rpi (3B, 3B+, 3A+, 4B and Zero W) ttyAMA0 serial console
-dtoverlay=miniuart-bt
+dtoverlay=miniuart-bt,krnbt=on
 __EOF__
                fi
                ;;