um well im lost as to why you are looking for source code, source code is the actual coding of programs and libraries before its compiled into something that is useable/runable on a device. if you need to fix a kindke you just need the system images to flash in fastboot typically. Personally i'm not familiar with how to restore a 2013 kindle, i assumed if someone would dd their system partition it woukd be as simple as flashing in fastboot, though i don't know if amazon changed the way the bootloader works like they did in the hdx's since they were released around the same time. The hdx's have no fastboot flashing capabilities thanks to amazon locking down on fastboot commands. I have heard instead they somehow fix their problems with adb but no clue as to how since that usually isnt available until the os boots up.
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