I have programmed in different
languages (nasm: hardware driver and math routines,
c++: frontend-QT, (pascal: normal code -could be written in nasm- ) ).
So I have at least two different objectfiles, those I wanted to link together
but I don't know how I can get the same variable-name (a.out and nasm.o; both elf) in the same section (section.data) in gcc. - To link them together, to use that one variable in both object-files.

Or should I write a third program to execude both programs
and initialize Pipes ?
Under Linux there is a systemcall called set_thread_area,
Is that a possibility ?

I hope there is somebody with a standard solution.
The communication have to be in both directions !

What you can do is is create your nasm.o and then when you compile the C++ program do g++ myprog.cpp nasm.o -o myprog

Or you can do g++ myprog.cpp -c which won't link the program, just create myprog.o. Then you can use ld to link myprog.o and nasm.o into the final executable by doing ld -o myprog myprog.o nasm.o

O.K. that I have done all.
My problem is to use a variable that's the same in both
object-files. ld uses only one offset if it sees, that 2 variables in a section
have the same name.
But I can't get gcc to write that variable name in a section (section.data or .bss).

I'm not really a c++ programmer (it's too complicaded). Assembler (NASM) is my favor.

In the C++ program, try declaring the variable as 'extern' (i.e. extern int somenum.

This tells the compiler or linker or something that the variable is actually declared in another file somewhere.

If that doesn't work, I have no idea.