3.1 ELF Header

The ELF header is always located at the beginning of the ELF file. It describes the ELF file organization and contains the actual sizes of the object file control structures. The initial bytes of an ELF header specify how the file is to be interpreted.

The ELF header contains the following information:

ehsize

ELF header size in bytes.

entry

Virtual address at which the process is to start. A value of 0 indicates no associated entry point.

flag

Processor-specific flags associated with the file.

ident

Marks the file as an object file and provides machine-independent data to decode and interpret the file contents.

machine

Specifies the required architecture for an individual file. A value of 2 specifies SPARC.

phentsize

Size in bytes of entries in the program header table. All entries are the same size.

phnum

Number of entries in program header table. A value of 0 indicates the file has no program header table.

phoff

Program header table file offset in bytes. The value of 0 indicates no program header.

shentsize

Size in bytes of the section header. A section header is one entry in the section header table; all entries are the same size.

shnum

Number of entries in section header table. A value of 0 indicates the file has no section header table.

shoff

Section header table file offset in bytes. The value of 0 indicates no section header.

shstrndx

Section header table index of the entry associated with the section name string table. A value of SHN_UNDEF indicates the file does not have a section name string table.

type

Identifies the object file type. Table 3–1 describes the reserved object file types.

version

Identifies the object file version.

Table 3–1 shows reserved object file types: