Find UART on the Qualcomm Galaxy S III devices
If you haven’t heard, and we’re not sure how you haven’t, there has been active development towards an open source bootloader for Samsung devices. In a nutshell, it involves loading the open source bootloader to an SD card, and using some hardware hacking skills to boot from it. All of this had to start somewhere, and among the first things required is finding the UART. It is now possible to identify it on the US variants of the Samsung Galaxy S III.
If you hadn’t guessed, this bit of hardware hacking awesomeness was done by XDA Elite Recognized Developer AdamOutler. This is very similar to work Adam has been doing for the Samsung Galaxy Camera, which you can find here. Why would this be helpful? AdamOutler explains it best:
UART provides eyes before any other method of debugging (aside from JTAG) begins to work. UART is the first thing to do in order to make a device into a development board.
The process of getting it is a little complicated, and if you’re a beginner, will probably take some time. Users will have to pull the kernel from the device, add some command line parameters to enable UART, and flash the kernel back to the device. Since you’ll need Ubuntu (or at least a Debian based distro) to follow along, you’ll be using Heimdall to do the flashing. Then, it’s a simple matter of tearing down the device without breaking it and probing the correct spot. Adam has uploaded a video that demonstrates the entire process the exact spot for UART. As can be expected, there is some danger because you are tearing open your device. Be sure to use the utmost caution and follow the directions.
As Adam states in the thread, he sometimes does these hacks live via a Google+ Hangouts live stream. They are a lot of fun to watch, give you a chance to learn some new things, and let you watch the magic as it happens. To catch the next one, circle Adam on Google+ and keep an eye out.
For the full video, all the details, and more, check out the original thread. Or, if you want to watch it happen, here’s Adam’s video: