These functions translate between the file and memory representations of ELF data structures. The in-memory representation of an ELF data structure would confirm to the byte ordering and data alignment restrictions dictated by the host processor. A file representation of the same data structure could use a non-native byte ordering and in addition may be laid out differently with the file.
Functions
elf32_xlatetom(),
elf64_xlatetom(), and
gelf_xlatetom() translate data from file representations to native, in-memory representations. Functions
elf32_xlatetof(),
elf64_xlatetof(), and
gelf_xlatetof() translate data from in-memory representations to file representations.
Argument
src denotes an
Elf_Data descriptor describing the source to be translated. The following elements of the descriptor need to be set before invoking these functions:
d_buf
Set to a valid pointer value denoting the beginning of the data area to be translated.
d_size
Set to the total size in bytes of the source data area to be translated.
d_type
Set to the type of the source data being translated. This value is one of the values defined in the
Elf_Type enumeration. The
Elf_Type enumeration is described in
elf(3).
d_version
Set to the version number of the ELF data structures being translated. Currently only version EV_CURRENT is supported.
Argument
dst describes the destination buffer. The following elements of the
Elf_Data descriptor need to be set before invoking these functions:
d_buf
Set to a valid pointer value that denotes the start of the destination buffer that will hold translated data. This value may be the same as that of the source buffer, in which case an in-place conversion will be attempted.
d_size
Set to the size of the destination buffer in bytes. This value will be modified if the function call succeeds.
d_version
Set to the desired version number of the destination. Currently only version EV_CURRENT is supported.
These translations routines allow the source and destination buffers to coincide, in which case an in-place translation will be done if the destination is large enough to hold the translated data. Other kinds of overlap between the source and destination buffers are not permitted.
On successful completion of the translation request the following fields of the
dst descriptor would be modified:
d_size
Set to the size in bytes of the translated data.
d_type
Set to the d_type value of the source data descriptor.
Argument
encode specifies the encoding in which the file objects are represented. It must be one of:
ELFDATANONE
File objects use the library's native byte ordering.
ELFDATA2LSB
File objects use a little-endian ordering.
ELFDATA2MSB
File objects use a big-endian ordering.
The functions
gelf_xlatetof() and
gelf_xlatetom() select the appropriate 32 or 64 bit translations based on the class of argument
elf.