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A shared object is an indivisible unit that is generated from one or more relocatable objects. Shared objects can be bound with dynamic executables to form a runable process. As their name implies, shared objects can be shared by more than one application.
What is a relocatable ELF file?
Introduction. This chapter describes the object file format, called ELF (Executable and Linking Format). There are three main types of object files. A relocatable file holds code and data suitable for linking with other object files to create an executable or a shared object file.
What are the types of object file format?
There are three main types of object files:
- A relocatable file holds sections containing code and data.
- An executable file holds a program that is ready to execute.
- A shared object file holds code and data suitable to be linked in two contexts.
How do object files work?
An object file is the real output from the compilation phase. It’s mostly machine code, but has info that allows a linker to see what symbols are in it as well as symbols it requires in order to work. (For reference, “symbols” are basically names of global objects, functions, etc.)
What does .O file contain?
The object file is the compiled source. This means that it’s machine code, which is dependent on the target platform (you can compile for Unix on Windows if you really want to) and the compiler used. Different compilers will produce different machine code from the same source file.
Which is the type of ELF object file?
In computing, the Executable and Linkable Format (ELF, formerly named Extensible Linking Format), is a common standard file format for executable files, object code, shared libraries, and core dumps.
What makes a relocatable object file an executable?
A relocatable fileholds code and data suitable for linking with other object files to create an executable or a shared object file. An executable fileholds a program suitable for execution; the file specifies how exec(BA_OS) creates a program’s process image.
What is the difference between shared object file?
There are relocatable files (similar to .o files) that are linked for the kernel and then loaded. Take the driver .o file or a file linked from several .o files via ld -o driver -r *.o and perform a final link step (using ld) that links that driver to load address 0. This is needed since the COMMON variables do not show up in the size output.
A shared object fileholds code and data suitable for linking in two contexts. First, the link editor [see ld(BA_OS)] processes the shared object file with other relocatable and shared object files to create another object file. Second, the dynamic linker combines it with an executable file and other shared objects to create a process image.
What are the different types of object files?
This chapter describes the object file format, called ELF (Executable and Linking Format). There are three main types of object files. A relocatable fileholds code and data suitable for linking with other object files to create an executable or a shared object file.