This article describes how to do in-system reprogramming of Kinetis devices using standard communication media such as SCI. Most of the codes are written in C so that make it easy to migrate to other MCUs. The solution has been already adopted by customers.
The pdf document is based on FRDM-KL26 demo board and Codewarrior 10.6. The bootloader and user application source codes are provided. GUI and video show are also provided. Now the bootloader source code is ported to KDS3.0, Keil5.15 and IAR7.40 which are also enclosed in the SW package. Customer can make their own bootloader applications based on them. The application can be used to upgrade single target board and multi boards connected through networks such as RS485. The bootloader application checks the availability of the nodes between the input address range, and upgrades firmware nodes one by one automatically.

Key features of the bootloader:
- Able to update (or just verify) either single or multiple devices in a network.
- Application code and bootloader code are in separated projects, convenient for mass production and firmware upgrading.
- Bootloader code size is small, only around 2K, which reduces the requirement of on chip memory resources.
- Source code available, easy for reading and migrating.
- GUI supports S19,HEX and BIN format burning images.
For more information, please see attached document and code.
The attached demo code is for KL26 which is Cortex - M0+ core. For Cortex-M4 core demo, refer this url:
https://community.freescale.com/docs/DOC-328365
User can also download the document and source code from Github:
https://github.com/jenniezhjun/Kinetis-Bootloader.git
Thank you from the great support from Chaohui Guo and his team.
Enjoy Bootloader programming :-)