Add device description for ZX310S-4T2XH

doc/devices/ZX310S-4T2XH.md

@@ -0,0 +1,59 @@
+# ZX310S-4T2XH/
+
+The following is a documentation for the managed switch marked as `ZX310S-4T2XH`
+and sold by Horaco.
+
+The original software is running UART on 57600 baud rate. The solder holes
+of the UART header are filled in. In order to install a UART header, they
+need to be cleared first. A 1.2mm drill can be used, alternatively a
+de-soldering wick.
+The original firmware uses 57600 baud 8N1
+
+CPU: RTL8372
+Flash: 2MByte Winbond W25Q16DV (U3)
+PHY RTL8261BE
+
+### Label specifications
+
+- **Name**: 
+- **Ports**:
+  - 4 × RJ45: 10/100/1000/2500 Mbps
+  - 1 x RJ45: 10/100/1000/2500/5000/10000 Mbps
+  - 1 × SFP+: 1000 / 2500 / 10000 Mbps
+- **Power**: 12V DC, 2A barrel connector 
+
+<img src="photos/ZX310S-4T2XH/label.jpg" width="300" />
+
+### What works
+The device is fully supported:
+- All 4 2.5GBASE-T RJ45 ports work at 10/100/1000/2500 Mbps
+- The 10GBit port works. TODO: Fix EEE, speed selection
+- The SFP+ port supports 1G, 2.5G and 10G modules 
+- LEDs work with the same indiciations as the OEM firmware
+
+### PCB overview
+
+**Board markings**
+- Top silkscreen: PCB-SL310S-4T1T1X-V1.0.1-24107
+
+Top side
+
+<img src="photos/ZX310S-4T2XH/pcb_top.jpg" width="300" />
+
+Bottom
+
+<img src="photos/ZX310S-4T2XH/pcb_bottom.jpg" width="300" />
+
+### J1, serial console
+
+| `J1` pin | Signal      |
+| -------- | ----------- |
+| 1        | TX (Output) |
+| 2        | RX (Input)  |
+| 3        | GND         |
+| 4        | 3V3         |
+
+
+## Power supply
+
+Input power is delivered via barell plug, `12V 2A` adapter was provided.