In a previous article I asked if the X-micro XWL-11GRIX broadband router might be running Linux. In the meantime I did get some responses from readers with additional information about this device.

First of all, Per Hansen wrote me about the 4 pin header and confirms that it is indeed a serial port. Here is what he has to say:

I read your article "*X-micro XWL-11GRIX running Linux?", and found you
have discovered some things that I also saw. You wondered what the 4 pin
header is for and I can confirm to you, it is an serial console.

The pinout is: starting from the pin closest to the nearby edge:
unknown
gnd
TX
RX 

Be aware, that the signals is 0-3.2v - not -/+ 12v as on the PC, so a
level converter is needed. 

Per also included some output from the console, which tells a few interesting things:

First of all, unlike for example the Linksys WRT54G and similar, this device actually talks to its serial port on a somewhat normal speed, 19.2 kbps, which means you can hook a noraml terminal to it.

The next thing that shows from the boot messages of the device is that it indeed seems to run Linux but there seems to be no shell installed.

No bif deal there however since there is a setup menu, which also allows loading new firmware images from tftp, including the option to load new firmware to ram and boot it without writing it to the flash.

The device has 2 ethernet ports, one connected to the wan port, and one to a 5 port switch (1 port is the SD9218, the other 4 are the lan connectors visible on the outside) and a Inprocomm wireless lan card (miniPCI). All the hardware should be supported without need for source code from X-micro according to the statements from Linpus, but I have not been able to verify that, nor do I know what tools to use to create an image for this device (other then using the SD9218 BSP package from SD or Linpus)

So.. connect a serial console to the device and you may have a very nice device to play with, capable of running Linux, and currently in fact running Linux. It allows experimenting with it without overwriting the onboard flash memory but the tools for creating an image that can be loaded on this device might be a bit of a problem. Anyone feeling like reverse engineering the RTOS TX image format? because that is what it seems to use.