How to reduce Kinetis flash bootloader v2.0.0 code size

[isaotakashima]

We want to implement firmware update mechanism to our system which use the KL17Z.

We understand that the KL17Z integrated ROM bootloader, but we want to use our custom protocol on the UART, then we cannot use it ROM bootloader.

NXP release below bootloader reference project.

- Developer’s Serial Bootloader (REV 13)
  http://cache.nxp.com/assets/documents/data/en/application-notes/AN2295.pdf
- NXP_Kinetis_Bootloader_2.0.0 package

We checked code size, the Developer’s Serial Bootloader code side is about 1KB, but NXP_Kinetis_Bootloader_2.0.0 package code size of KL25Z is about 16KB even if enable only UART.

So, we cannot find out URL link address of the AN2295SW.zip now. But we had download AN2295SW.zip few years ago, then we can build it project and check code size.

Therefore we think that it is better to use NXP_Kinetis_Bootloader_2.0.0 package.

But it code size is very large.

Here is our questions.

1. Does NXP recommend that use NXP_Kinetis_Bootloader_2.0.0 package instead of Developer’s Serial Bootloader(AN2295SW)?

2. Please advise how to reduce NXP_Kinetis_Bootloader_2.0.0 package code size.

3. If we can use Developer’s Serial Bootloader(AN2295SW), please let us know URL link address of AN2295SW.zip.

Please reply as soon as possible.

Best regards,

Takashima

[Hui_Ma]

Hi,

1. Does NXP recommend that use NXP_Kinetis_Bootloader_2.0.0 package instead of Developer’s Serial Bootloader(AN2295SW)?
TS: The Kinetis Bootloader with higher priority recommended bootloader software for Kinetis products, which supports more communication ports and bootloader examples for many Kinetis devices.  

2. Please advise how to reduce NXP_Kinetis_Bootloader_2.0.0 package code size.
TS: I do a test with the KL25 [freedom_bootloader] <bootloader__config.h> file with below test result:
Support UART, I2C, SPI, USB HID and USB MSC

  29 048 bytes of readonly  code memory
   2 504 bytes of readonly  data memory
   8 199 bytes of readwrite data memory
   
Only support UART module
  13 286 bytes of readonly  code memory
     838 bytes of readonly  data memory
   5 100 bytes of readwrite data memory   

The AN2295 KL25 footprint is :
  964 bytes of readonly  code memory
   80 bytes of readonly  data memory
  412 bytes of readwrite data memory

From the bootloader code size, the AN2295SW shows advantage.
If customer consider most important factor of the serial bootloader is code footprint, the AN2295 should be selected.

3. If we can use Developer’s Serial Bootloader(AN2295SW), please let us know URL link address of AN2295SW.zip.
TS: The NXP website doesn't provide AN2295SW download, please check below thread to download the AN2295SW.
https://community.nxp.com/message/911628?commentID=911628#comment-911628

Have a great day,
Ma Hui

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