Learn How to Run a ROM Off Your External SD Card
Aftermarket modding has been around since practically the beginning of the modern day smartphone, but its build-up on Android has been pretty explosive. Since the early days of the HTC Dream right up to the current generation of devices, almost every device has received its fair share of third party modifications. These can come in the form of ROMs, kernels, scripts and more, but ROM development has taken front and center stage. Obviously, the word ROM stands for Read Only Memory. And for our modern devices, that’s the NAND-based Flash ROM that makes up their internal storage. However, in the development community, the term has come to mean a custom operating system image that you install (or flash) onto the internal storage of your device.
So what are you supposed to do if this internal memory gets corrupted somehow? Expensive paperweight? Not yet, as XDA Member lexelby was faced with this exact dilemma and detailed a solution. Lexelby’s method involves running a ROM off your external SD card, which requires you to partition your SD card into a format that will allow you to boot the ROM, such as the EXT4 format.
Head over to the dead mmc thread to get started, where lexelby posted the problem and subsequently, the solution, which states with a fair amount of confidence that it should be compatible with any device, given that the kernel supports kexec.