>>So can you give me any reference to copy a code into RAM to execute it.
No, you can presumably read the content of the EEPROM into RAM already.
Execution would require the code be built for the location you load it, entry could be made with a table of function addresses, and function pointers in C, or branches or calls in assembler.
People have moved away from supporting overlay methods in linkers, so you might need to consider building a loader which can pull in .ELF files, so those can be built as individual executables or DLLs. One could probably still do overlays, but it would require a conceptual understanding of the method, and an ability to separate out functional blocks of code that operate independently/separately.
Not really sure how large your code is, and how much, memory you have to work with, or if you need to partition your design better.
The complexity here is probably beyond the scope of free forum support.
