How to communicate between SPE and Linux kernel?

I checked the methods mentioned below:

My device is Jetson AGX Xavier.

I updated the file tegra194-aon.dtsi as below:

                  ivc_aon_shub@d880 {
                            reg = <0xd880>, <0x1d880>;
                            reg-names = "rx", "tx";
                            nvidia,frame-count = <32>;
                            nvidia,frame-size = <256>;

aon_echo {
	compatible = "nvidia,tegra186-aon-ivc-echo";
	mboxes = <&aon 0>;
	status = "okay";

aondbg {
	compatible = "nvidia,tegra186-aondbg";
	mboxes = <&aon 1>;
	status = "okay";

I put the scripts in the above aon_echo.

I compiled the kernel source and flashed the board, but the /sys/devices/aon_echo/data_channel didn’t appear.

Is there any steps necessary that I missed? Or is there any steps wrong?

Should I modify the SPE source file and flash?

Currently, what I want is making the communication between Kernel and SPE works.