A Playground for Firmware development for advanced user of RTL8372/RTL8373 based 2.5GBit Switches.
For each hardware configuration of these devices, there is usually a managed and an umanaged version sold, with mostly identical hardware. The aim is to provide management features also for unmanaged devices with additional features such as Management VLAN, dhcp servers, multi-language support, IPv6 and TLS-encrypted web-pages. At present, however only the following features are provided:
- A modern web-interface with mouse-over to display further information
- A serial console interface to configure all features
- IGMP to configure Multicast streaming
- Port configuration showing detailed informtion about own and Link-partner advertised Speed settins and configuration of these settings on the local side
- Per-port configuration of frame sizes (MTUs) for Jumbo-Frame support or limiting MTUs for particular devices
- EEE (Energy Efficient Ethernet) can be configured per-port. Detailed information is provided for support offered by the link partner and the EEE status of a port.
- VLAN configuration
- SFP information is displayed on the inserted modules, the current sensor values such as temperatures, RX and TX power are displayed in the CLI and as mouse-over on the web
- Mirror configuration
- Link Aggregation Groups can be set up
- Detailed information on port packet statistics
- Configuration saved to flash via the web-interface
- Firmware updates via the web
- Installation as a firmware upgrade from the original web-interface
While the firmware provides already considerable improvements over the original managed firmware, the firmware still lacks support for STP and the proprietary loop prevention protocols as well as DHCP. If you need these features, do not install the playground on your managed devices. In any case, installation is strongly discouraged unless you can at least make a backup of the original flash content via a SOIC clamp such as also used for BIOS backups and can re-install that firmware in case something is wrong. For this no soldering skills are necessary.
The firmware supports all hardware featues of devices with
- 4 2.5GBit ports + 2 SFP+ ports
- 5 2.5GBIT + 1 SFP+ port
- 8 2.5GBit + 1 SFP+ port Devices sold usually have a fairly common design, however there may be differences in the LED configuration (switches have LEDs with different colours and use types of LEDs). The list of tested devices can be found in Supported devices.
To do meaningful development you will need to use a serial console, so soldering skills are required. Flashing must be done via a SOIC-8 PatchClamp or by soldering a socket for the flash chip.
If you don't want to open your device, you can use the project's code to learn about the devices by looking at the image using e.g. Ghidra. If you want to contribute to the design of the web-interface or get a feeling for the interface first, a standalone device simulator is provided, which runs entirely under Linux as a local webserver.
Install the following particular build requisites (Debian 12/13), note that Ubuntu 24.04 still has an older version of sdcc, but you will need sdcc version 4.5 for the code to compile:
sudo apt install sdcc xxd python-is-python3 libjson-c-dev
Now, building the firmware image should work:
$ make
sdas8051 -plosgff crtstart.asm
sdcc -mmcs51 -c rtlplayground.c
sdcc -mmcs51 -c rtl837x_flash.c
sdcc -mmcs51 -Wl-bHOME=0x100 -o rtlplayground.ihx crtstart.rel rtlplayground.rel rtl837x_flash.rel
objcopy --input-target=ihex -O binary rtlplayground.ihx rtlplayground.img
if [ -e rtlplayground.bin ]; then rm rtlplayground.bin; fi
echo "0000000: 00 40" | xxd -r - rtlplayground.bin
cat rtlplayground.img >> rtlplayground.bin
Note, that the image generated ends in .bin, not .img, in order to make IMSProg happy.
Managed switches can be updated from the existing original firmware using an upgrade image.
In the installerfolder of the source code you will need to run make which will build
an image out of rtlplayground.bin built in the previous step:
RTLPlayground/installer$ make
mkdir -p output/
gcc updatebuilder.c -o output/updatebuilder
sdas8051 -plosgff -o output/crtstart.rel crtstart.asm
sdcc -mmcs51 --code-loc 0x1000 -o output/installer.rel -c installer.c
sdcc -mmcs51 -Wl-bHOME=0x1100 -Wl-r -o output/rtlinstaller.ihx output/crtstart.rel output/installer.rel
cp ../output//rtlplayground.bin output/
./output//updatebuilder -i output/rtlinstaller.ihx output/rtlplayground.bin
Input file size: 524288
Bytes read: 524288
EOF
Payload sum 1 is: 0x29d10
Payload sum 2 is: 0x29d10
Payload sum with header is: 0x2b0fc
Payload sum is: 0xad8a75
Header checksum is: 0x4c3
The resulting image can be found in RTLPlayground/installer/output/rtlplayground.bin
Caution
DO NOT UPLOAD THE UPGADE IMAGE UNLESS YOU CAN MAKE A BACKUP USING A SOIC CLAMP OF THE ORIGINAL FIRMWARE!
You can play with the image using ghidra or flash real Switch Hardware. For ghidra see this information about Ghidra images.
Caution
NOTE THAT WHILE THIS PROCEDURE HAS BEEN SUCCESSFULLY TESTED ON ALL DEVICES ABOVE, ABSOLUTELY NO GUARANTY CAN BE GIVEN THAT YOU WILL NOT DESTROY YOUR SWITCH, ANY OTHER EQUIPMENT INVOLVED OR HARM YOURSELF BY OPENING THE ELECTRONIC DEVICE. OPENING THE SWITCH WILL VOID ITS WARRANTY.
You can upload the upgrade image of managed switches via the web interface of the original firmware just as if you were installing a firmware upgrade. However, this is strongly discouraged, as you may brick your device, unless you can make firmware backups via a SOIC clamp or soldered flash socket, first!
For unmanaged devices, the only way to install RTLPlayground is by flashing the Flash memory directly.
You will need to open your switch to flash the image directly onto the flash chip, which is done easiest using a SOIC-8 clip (alternatively you de-solder the flash chip and install a SOIC adapter):
- Disconnect power from switch
- Attach the clip onto the flash chip
- Connect USB of flash programmer, the power LED on the switch will light up, check cabling if not. Don't panic, mixing up GND and 3.3V does not seem to destroy the switch (at leasts the on I did this to).
- Use IMSProg (flashrom should work, too) to detect the clip
- MAKE A BACKUP OF THE EXISTING FIRMWARE!
- then load the firmware into IMSProg
- and program flash
Now you can connect a serial cable to the UART port found on all the devices, set 8N1 @ 115200 baud and power up the switch.
The device will perform some examples and provide a minimal console, the documentation of which can be found in the source code rtlplayground.c`.
The web-interface can be reached under the default 192.168.10.247.
The default password is 1234.
The command line is very rudimentary and mostly for testing purposes. The following is a boot-log with some examples:
Detecting CPU
RTL8373 detected
Starting up...
Flash controller
NIC reset
rtl8372_init called
RTL837X_REG_SDS_MODES: 0x00000bed
phy_config_8224 called
phy_config_8224 done
rtl8224_phy_enable called
rtl8224_phy_enable done
rtl8372_init done
A minimal prompt to explore the RTL8372:
CPU detected: RTL8373
Clock register: 0x00001101
Register 0x7b20/RTL837X_REG_SDS_MODES: 0x00000bed
Verifying PHY settings:
Port State Link TxGood TxBad RxGood RxBad
1 On Down 0x00000000 0x00000000 0x00000000 0x00000000
2 On Down 0x00000000 0x00000000 0x00000000 0x00000000
3 On Down 0x00000000 0x00000000 0x00000000 0x00000000
4 On Down 0x00000000 0x00000000 0x00000000 0x00000000
5 On 2.5G 0x00000008 0x00000000 0x00000000 0x00000000
6 On Down 0x00000000 0x00000000 0x00000000 0x00000000
7 On Down 0x00000000 0x00000000 0x00000000 0x00000000
8 On Down 0x00000000 0x00000000 0x00000000 0x00000000
9 NO SFP Down 0x00000000 0x00000000 0x00000000 0x00000000
> port 5 1g
CMD: port 5 1g
PORT 04 1G
> stat
CMD: stat
Port State Link TxGood TxBad RxGood RxBad
1 On Down 0x00000000 0x00000000 0x00000000 0x00000000
2 On Down 0x00000000 0x00000000 0x00000000 0x00000000
3 On Down 0x00000000 0x00000000 0x00000000 0x00000000
4 On Down 0x00000000 0x00000000 0x00000000 0x00000000
5 On 1000M 0x00000035 0x00000000 0x00000017 0x00000000
6 On Down 0x00000000 0x00000000 0x00000000 0x00000000
7 On Down 0x00000000 0x00000000 0x00000000 0x00000000
8 On Down 0x00000000 0x00000000 0x00000000 0x00000000
9 NO SFP Down 0x00000000 0x00000000 0x00000000 0x00000000
>
<SFP-RX OK>
<MODULE INSERTED> Rate: 67 Encoding: 01
Lightron Inc. WSPXG-ES3LC-IHA 0000
> stat
CMD: stat
Port State Link TxGood TxBad RxGood RxBad
1 On Down 0x00000000 0x00000000 0x00000000 0x00000000
2 On Down 0x00000000 0x00000000 0x00000000 0x00000000
3 On Down 0x00000000 0x00000000 0x00000000 0x00000000
4 On Down 0x00000000 0x00000000 0x00000000 0x00000000
5 On 1000M 0x00000065 0x00000000 0x0000003b 0x00000000
6 On Down 0x00000000 0x00000000 0x00000000 0x00000000
7 On Down 0x00000000 0x00000000 0x00000000 0x00000000
8 On Down 0x00000000 0x00000000 0x00000000 0x00000000
9 SFP OK 10G 0x00000000 0x00000000 0x0000001c 0x00000000
> sfp
CMD: sfp
Rate: 67 Encoding: 01
Lightron Inc. WSPXG-ES3LC-IHA 0000
Enjoy playing!
The following documents give further documentation on specific features of the RTL837x SoCs: