ELF_XLATE(3E)ELF_XLATE(3E)


NAME
     elf_xlate, elf32_xlatetof, elf32_xlatetom, elf64_xlatetof,
     elf64_xlatetom - Performs class-dependent data translation

SYNOPSIS
     cc [flag ...] file ...  -lelf [library ...]

     #include <libelf.h>

     Elf_Data *elf32_xlatetof(Elf_Data *dst, const Elf_Data *src, unsigned
     encode);

     Elf_Data *elf32_xlatetom(Elf_Data *dst, const Elf_Data *src, unsigned
     encode);

     Elf_Data *elf64_xlatetof(Elf_Data *dst, const Elf_Data *src, unsigned
     encode);

     Elf_Data *elf64_xlatetom(Elf_Data *dst, const Elf_Data *src, unsigned
     encode);

DESCRIPTION
     elf32_xlatetom translates various data structures from their 32-bit
     class file representations to their memory representations;
     elf32_xlatetof provides the inverse.  This conversion is particularly
     important for cross development environments.  src is a pointer to the
     source buffer that holds the original data; dst is a pointer to a
     destination buffer that will hold the translated copy.  encode gives
     the byte encoding in which the file objects are (to be) represented
     and must have one of the encoding values defined for the ELF header's
     e_ident(EI_DATA) entry; see elf_getident(3E).  If the data can be
     translated, the functions return dst.  If an error occurred, such as
     incompatible types, destination buffer overflow, etc., they return
     null.

     elf_getdata(3E) describes the Elf_Data descriptor, which the
     translation routines use as follows:

     d_buf         Both the source and destination must have valid buffer
                   pointers.

     d_type        This member's value specifies the type of the data to
                   which d_buf points and the type of data to be created in
                   the destination.  The program supplies a d_type value in
                   the source; the library sets the destination's d_type to
                   the same value.  These values are summarized below.

     d_size        This member holds the total size, in bytes, of the
                   memory occupied by the source data and the size
                   allocated for the destination data.  If the destination
                   buffer is not large enough, the routines do not change
                   its original contents.  The translation routines reset
                   the destination's d_size member to the actual size
                   required, after the translation occurs.  The source and
                   destination sizes may differ.

     d_version     This member holds version number of the objects
                   (desired) in the buffer.  The source and destination
                   versions are independent.

     Translation routines allow the source and destination buffers to
     coincide.  That is, dst->d_buf may equal src->d_buf.  Other cases
     where the source and destination buffers overlap give undefined
     behavior.

     Elf_Type      32-Bit Memory Type

     ELF_T_ADDR    Elf32_Addr

     ELF_T_BYTE    unsigned char

     ELF_T_DYN     Elf32_Dyn

     ELF_T_EHDR    Elf32_Ehdr

     ELF_T_HALF    Elf32_Half

     ELT_T_OFF     Elf32_Off

     ELF_T_PHDR    Elf32_Phdr

     ELF_T_REL     Elf32_Rel

     ELF_T_RELA    Elf32_Rela

     ELF_T_SHDR    Elf32_Shdr

     ELF_T_SWORD   Elf32_Sword

     ELF_T_SYM     Elf32_Sym

     ELF_T_WORD    Elf32_Word

     Translating buffers of type ELF_T_BYTE does not change the byte order.

     The 64-bit class works identically, simply replacing all instances of
     32 in the description and table with 64.

NOTES
     By default, the Elf_Data used for the 64-bit class in a 32-bit
     application restricts one to building 64-bit class applications with
     only 32-bit fields unless the entire application is compiled with
     _LIBELF_XTND_64 defined; see elf(3e).

SEE ALSO
     elf(3E), elf_fsize(3E), elf_getdata(3E), elf_getident(3E)