topic Creating a fixed location for bootloader code in ColdFire/68K Microcontrollers and Processors

Creating a fixed location for bootloader code

tminnich — Wed, 21 Oct 2009 01:59:30 GMT

I have a bootloader that works well and I would like my MCF51QE128 project (linker control file?) to formally place the function (void)Boatload_Main(void) at a fixed location. While I am unlikely to move or modify the code I would prefer to have it explicitly tied to a given location.

regards Tom M.

Re: Creating a fixed location for bootloader code

J2MEJediMaster — Wed, 21 Oct 2009 22:53:27 GMT

Check out FAQ-27631. While it discusses how to locate constants at specific addresses in flash memory, the technique might be useful for what you are trying to do.

---Tom

Re: Creating a fixed location for bootloader code

tminnich — Thu, 22 Oct 2009 21:49:18 GMT

I have found a bug in the bootloader and now must modify the code. The entry point of the code

void BootloaderMain(void) must not change. I have tried a few linker control file directives OBJECT, ALIGN and updates to the location counter, without the result I am looking for.

I suppose I could force the function into its own memory segment, but I'd like to use the tools they way they are intended ( with the least brute force).

regards Tom M

Re: Creating a fixed location for bootloader code

CrasyCat — Fri, 23 Oct 2009 18:46:10 GMT

Hello

In order to allocate a function at an absolute address you need to place it in a user defined section and specify where you want to allocate that code in the .lcf file.

That is the only way to achieve that with a function.

CrasyCat