Hi,
after you execute "Flash to file" to download a file(for instance blinking led) to target flash, then power off the target then power on. the content you flashed to target is still there. the blinking led program can run normally.
from your original question you want to develop a bootloader?
here is an article i ever wrote regarding to how to develop a bootloader for Cortex M0+ core kinetis. you may refer it if you need:
Kinetis Bootloader to Update Multiple Devices in a Network - for Cortex-M0+
Have a great day,
Jennie Zhang
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