Anyway, move on a bit and the original Sat Nav was getting creaky. Firmware update for this version of TomTom does require a passcode. However when a person 'bricks” this tends to be done accidentally - normally whilst trying to upgrade, hack or unlock the device. Satnav makers like tomtom put.
The following is an excerpt from the ExtremeTech book Hacking GPS.
One guaranteed way to personalize your GPS is to update and modify the firmware that controls the actual running of the device. We’ll be looking at how you can modify your GPS at a fundamental level.
Firmware Firmware is the software that controls how hardware works and responds to inputs. It’s called firmware instead of software because users generally aren’t supposed to play around with it. But you’re not just any old user, are you? Almost all electronic hardware contains some form of firmware. A television remote control contains firmware that controls what signals are sent via IR depending on what button is pressed. A cell phone contains a lot of firmware controlling cell access, phone books, security, and much, much more. A GPS contains a lot of firmware controlling many of the key functions of the device (as shown in Figure 6-1):
Reception of satellite data
Decoding of positional information
Processing of data
Conversion of data into different formats
Interpretation and display of information
External communication with devices
Storing and managing route/waypoint data
FIGURE 6-1:
As you can see, being able to influence the firmware means you have influence on the actual workings of the GPS receiver itself. Not only can you make alterations to the text that is displayed on the screen of the GPS, you can also hide features that get in the way (such as startup screens). You can also add your contact details to the GPS in such a way that would discourage theft of your unit and encourage its return to you if it were found.