Hi all,
my PW2 arrived last week and it kind of bothered me that I couldn't put my favourite screensaver on it. So, after reading this thread, I decided to give rooting via the serial console a try.
Disassembly was surprisingly easy:
Since I do not want to disassemble the device again whenever I need access to the console, I looked for a way to make the serial port accessible from outside. There is just enough space between the button and the LED cover to squeeze in a 1.27mm header connector with four ports. I had to saw halfway through the connector at the second hole from the bottom in order to slip it on to the PCB. Closing this hole with epoxy also makes the connector asymmetric.
Next I had to connect the two data pins at the top of the connector to the RX/TX pads on the PCB. Enamelled wire comes in real handy here. The third contact at the bottom of the connector is wired to GND under the PCB.
First test after soldering. To my great surprise, everything worked and I could play around with u-boot.
Now came the really hard part, fitting everything into the housing again. I had to remove one of the straps holding the button and carve a slot so the connector would be accessible from outside.
From here on it was easy sailing. After figuring out how to get into the diagnostics system, I first made backups of all other partitions via the user storage, then re-enabled root login on mmcblk0p1. Once I had root access on the main system, I was finally able to do what what I came for in the first place:
Many thanks to knc1 for the metric ton of information about the layout of the embedded Linux system given in this thread and also to npoland, who demonstrated how easy the serial console can be accessed.
- Tido