Obviously, you have to develop ISP/IAP according to FSL's application note for bootloader. So far you can find following reference designs from FSL.
- UART based serial bootloader (AN2295), as regular serial device
- USB MSD host bootloader (AN4368), as USB host, you can put firmware on USB stick,
- USB DFU device bootloader (AN4370), as Device Firmware Upgrade class, however you must implement other classes such as HID/CDC with DFU, which I personally verified it on KL25Z, and it works.
- USB MSD device bootloader (AN4379), as USB stick, you can copy firmware to emulated USB stick.
- USB MSD device/host secure bootloader (AN4605)
The bootloader takes some user code space. Furthermore, user code has move its ISR to RAM. I prefer FSL can follows NXP's implementation, which has on board ISP, and it is separated from user space.
