NAME

elf_xlate: elf32_xlatetof, elf32_xlatetom - 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);

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. Otherwise, they return null because an error occurred, such as incompatible types, destination buffer overflow, etc. 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 des-
              tination buffers to coincide.  That  is,  dst-
              >d_buf  may  equal  src->d_buf.   Other  cases
              where the source and destination buffers over-
              lap 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.

SEE ALSO

elf(3E), elf_fsize(3E), elf_getdata(3E), elf_getident(3E).