ELF is the abbreviation for Executable and Linkable Format and defines the structure for binaries, libraries, and core files.

When user-space call to execve():

• check ELF magic
• check for an interpreter
• load_elf_phdrs() - load segments (PT_LOAD)
• Set entry point
• create_elf_tables() , prepare auxiliary vector, environment and arguments
• start_thread()

!Populating the stack: the auxiliary vector, environment and arguments

The create_elf_tables() function adds more information to the new program's stack

The first collection of information forms the ELF auxiliary vector, a collection of (id, value) pairs that describe useful information about the program being run and the environment it is running in, communicated from the kernel to user space.

• The  argument count is inserted first.
• An array of argument pointers is inserted next, ending with a NULL pointer.
• An array of environment pointers is inserted next, ending with a NULL pointer
• The auxiliary vector is put at the highest address, just below the additional values it references.