At the risk of hijacking the thread, does anyone know if there are other serial interfaces available inside the Kindle 3?
The i.MX35 has three UARTs, and it's easy to find which balls the signals are on from the Freescale's tech docs, but I have no way of knowing if those balls are routed anywhere. Amazon's kernel is finding all three and assigning them ttymxc0, ttymxc1, and ttymxc2. Of course, the console getty process runs on ttymxc0.
I've thought of hooking up a GPS with serial output, but it seems pretty dangerous to disable the serial console for that purpose. It's the last line of defense if I do something stupid and need u-boot access. Looking at all those test points on the PCB, I wonder if some of them are ttymxc1 or ttymxc2? Anyone know?