I spent some time over the long President’s Day weekend hacking some of my home devices with the goal of putting new firmware on them. Up until now this has consisted mostly of flashing custom firmware through the existing upgrade channels of whatever device I was working with. Other times I would flash the devices by having them download new firmware from a fileserver.
Sometimes, though, there is no other way to bend a device to your will than to tap into the device’s serial console. This is often done by using a special adapter to convert the low-level signals into the kind that a modem would use. Then you simply use any suitable terminal program to interact with the device. Even though most embedded devices do not come with real computer screens, one can use the serial console to read messages and type commands.
My new serial cable arrives this week which should allow me to unlock nearly any device in my home. I’m looking forward to voiding some more warranties!