The only effective way to do a boot loader in C language is to write it as a separate program from the application. Then both programs have to be merged at the binary or Hex file level to produce a single load image for the MCU. If you follow the recommendations of myself and certain other professionals here it is highly advantageous to have the boot loader built as an intrinsic part of the application. For this to work it is necessary to write the loader portion in assembler language. This is exactly the way that some boot loader code that I linked to in my other posting to this thread is structured.

If you insist that the boot loader and the application both need to be written in C language then you should go study a sample that is built like this. I believe there is such a sample presented in an applications note at the SiLabs web site.


Michael Karas