Hints on porting KL25Z bootloader to KL27Z bootloader

[robertpoor]

I've managed to compile and load a semi-custom bootloader on the FRDM-KL25Z.  

Now my challenge is to port the bootloader to the KL27Z.  I understand -- in theory -- the basic pieces that need to change, most obviously everything in the KL25Z directory.  

But much of this is relatively undocumented, so if anyone has been down the path of porting a bootloader from Architecture A to Architecture B, I'd very much like to learn from your experience.   In the meantime, I'll just start grinding through the files one at a time.

Thank you in advance!

- Robert Poor

[kerryzhou]

Hi Robert Poor,

    KL27 already have the ROM bootloader, KL25 don't have the ROM bootloader, so KL25 need to use the flash bootloader.

   But, KL27 already have the UART, I2C, SPI and USB ROM bootloader.

   You can use it directly.

    About the ROM bootloader usage, please refer to the document in the KBOOT2.0, the name is:Getting Started with the Kinetis ROM Bootloader.pdf.

   KBOOT2.0 can be downloaded from this link:

NXP_Kinetis_Bootloader_2.0.0 package

  Doc folder: NXP_Kinetis_Bootloader_2_0_0\doc

Wish it helps you!

Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[robertpoor]

Hi Kerry,

Thank you for the response, but it won't help in my case.  

We cannot use the KL27Z ROM bootloader because our device *only* communicates via LPUART1.  In addition to that, serial communication is half-duplex, so we need to modify the serial drivers.  This is why I'm porting the flash bootloader to the KL27Z.

I've already downloaded KBOOT 2.0.

The strategy I'm taking right now is to create a full Kinetis 2.0 project for the KL27Z, then copy the files over one at a time from the KL25Z flash bootloader, adapting them to the file structure in a Kinetis 2.0 project and modifying as needed for a KL27Z.  So far, that seems to be a workable strategy.

- Robert

[kerryzhou · Accepted solution]

Hi Robert Poor,

   I got it.

   I have a KL43 mini bootloader .

   I think you can refer to it, it is very simply, the bootloader code is also very small.

  But, now it just have the MDK project, you can refer to it. KL43 is similar to KL27, you can use it, but you need to change the header file and other according files to KL27, eg, system_<device>.h, and the startup file.

 Please check the attachment.

  After you modify it, you can use the kboot2.0 KinetisFlashTool to download the application code.

Wish it helps you!

Have a great day,
Kerry

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[robertpoor]

Bingo!  I believe this is exactly what I need: it's very compact without all the complexity of the FRDM-KL25Z flash loader.  

I will mark this "solved" for now and let you know if I get stuck on any aspects of porting.

Thank you very much.

- Robert Poor