Linking is the last step in the creation of the ELF file. The cross-compiling GCC groups all the object files together and resolves the dependencies among symbols. By passing the -T filename option at the command line, the linker is asked to replace the default memory layout for the program with a custom script, contained in the filename.
The linker script is a file containing the description of the memory sections in the target, which need to be known in advance in order for the linker to place the symbols in the correct sections in flash, and instruct the software components about special locations in the memory mapping area that can be referenced in the code. The file is recognizable by its .ld extension, and it ...