Can we specify particular C's user defined function to fixed(as we give) location(offset)?

Yes it is possible to specify things like this. Look closely at the Keil Linker manual and study the command line switches for the linker.

One would have to ask why you want to have a hard fixed user routine. Under normal circumstances it is best to simply recompile and link all your code routines each time you re-compile / link / and download new code. There are special applications of course but they would seem to be few and far between to me.

It would be easier to understand the need to possibly hard code the location of variables like say in a part that has onboard EEPROM or user configureable FLASH data memory. It is also possible to hard locate data elements.

But hard coding the address of where a user function goes, especially a C routine, seems questionable to me. If you could think this through and describe more what you are trying to acheive then maybe you could see through to a way to avoid hard coding the user function start address.

There is sometimes a need to place an in-application boot loader at the base of the memory just beyound the interrupt vectors and then place all C code (as "application" code) above a certain boundary. This can be done best by studying the process of relocating the interrupt vector table for the C modules. If you are doing this kind of thing lets have more discussion. Keil has knowledge base information also about this process and I have some loader source code I am willing to share. Note that my concept of doing an in application FLASH loader is a bit different from the way others have done it. Many do it with separate souce compiles for the loader and the application whereas I have schemed to do it with just one source compile.


Michael Karas