I am planning to use the microcontroller MK22FN1M0AVMC12 in a custom board and I need to include bootloader capabilities on it.
I have been looking into the KBOOT Kinetis Bootloader V2.0 and have some questions regarding its use for this specific microcontroller:
1. I see there is a bootloader for MK22F51212, which is basically the same microcontroller I intend to use but with less memory. Does this bootloader work 'out of the box' for the MK22FN1M0AVMC12? Should I do any modification to the code?
2. I also see there are multiple alternatives in the folder of the bootloader provided for Kinetis Design Studio: Flashloader, Flashloader_loader, Freedom_bootloader, and tower_bootloader. Since I am not using any of the development kits like the freedom or the tower, which version should I use? What would be the differences?
3. In my application I am planning to have only two buttons available. Is this enough for the complete bootloader capabilities? I would mainly like to be able to update my firmware through USB with no additional connections. From what I see the bootloader could be either started at startup when a USB is connected and attempting to establish bootloader connection, or even calling a function from my application, but I just want to make sure that no extra pins are required to be available, since as I mentioned, the application will only have two GPIOs available as buttons.
Thank you in advance!