Okay, sadly seems those overlays are either broken or do not work in Odroid N2. Since it fits the case, I explained the situations with those overlays provided by Armbian in general here: Why is hardware peripherals setup / config (e.g. using device tree overlay) hidden from view - #7 by MichaIng
I’ll however test/verify this on my Odroid N2+ and see whether it can be trivially fixed, respectively whether there is a simple functional status toggle for UART1.
For my own reference, here is the Armbian patch to add those overlays: build/general-meson64-overlays.patch at e33842ef2c2fefecbcd7c14724c0cff5250cd34a · armbian/build · GitHub
diff --git a/arch/arm64/boot/dts/amlogic/overlay/meson-uartA.dts b/arch/arm64/boot/dts/amlogic/overlay/meson-uartA.dts
new file mode 100644
index 000000000000..3aecd60aaf64
--- /dev/null
+++ b/arch/arm64/boot/dts/amlogic/overlay/meson-uartA.dts
@@ -0,0 +1,11 @@
+/dts-v1/;
+
+/ {
+ compatible = "amlogic,meson-gxbb";
+ fragment@0 {
+ target-path = "/soc/bus@c1100000/serial@84c0";
+ __overlay__ {
+ status = "okay";
+ };
+ };
+};
diff --git a/arch/arm64/boot/dts/amlogic/overlay/meson-uartC.dts b/arch/arm64/boot/dts/amlogic/overlay/meson-uartC.dts
new file mode 100644
index 000000000000..2b40ee4c02d3
--- /dev/null
+++ b/arch/arm64/boot/dts/amlogic/overlay/meson-uartC.dts
@@ -0,0 +1,11 @@
+/dts-v1/;
+
+/ {
+ compatible = "amlogic,meson-gxbb";
+ fragment@0 {
+ target-path = "/soc/bus@c1100000/serial@8700";
+ __overlay__ {
+ status = "okay";
+ };
+ };
+};
So we need to check whether /proc/device-tree/soc/bus@c1100000/serial@84c0/status and /proc/device-tree/soc/bus@c1100000/serial@8700/status still exist or whether something changed about this with recent Linux.