elf_xlate(3elf)

elf_xlate: elf32_xlatetof, elf32_xlatetom, elf64_xlatetof, elf64_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);
   

   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. elf64_xlatetom and elf64_xlatetof provide the same functionality for 64-bit class files. 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(3elf)]. 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, and so forth.

elf_getdata(3elf) describes the Elf_Data descriptor, which the translation routines use as follows.

Both the source and destination must have valid buffer pointers.
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.
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.
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 64-Bit Memory Type

ELF_T_ADDR Elf32_Addr Elf64_Addr

ELF_T_BYTE unsigned char unsigned char

ELF_T_DYN Elf32_Dyn Elf64_Dyn

ELF_T_EHDR Elf32_Ehdr Elf64_Fhdr

ELF_T_HALF Elf32_Half Elf64_Half

ELT_T_OFF Elf32_Off Elf64_Off

ELF_T_PHDR Elf32_Phdr Elf64_Phdr

ELF_T_REL Elf32_Rel Elf64_Rel

ELF_T_RELA Elf32_Rela Elf64_Rela

ELF_T_SHDR Elf32_Shdr Elf64_Shdr

ELF_T_SWORD Elf32_Sword Elf64_Sword

ELF_T_SYM Elf32_Sym Elf64_Sym

ELF_T_WORD Elf32_Word Elf64_Word

ELF_T_XWORD Elf64_Xword

ELF_T_SXWORD Elf64_Sxword

Elf_Type	32-Bit Memory Type	64-Bit Memory Type
`ELF_T_ADDR`	`Elf32_Addr`	`Elf64_Addr`
`ELF_T_BYTE`	`unsigned char`	`unsigned char`
`ELF_T_DYN`	`Elf32_Dyn`	`Elf64_Dyn`
`ELF_T_EHDR`	`Elf32_Ehdr`	`Elf64_Fhdr`
`ELF_T_HALF`	`Elf32_Half`	`Elf64_Half`
`ELT_T_OFF`	`Elf32_Off`	`Elf64_Off`
`ELF_T_PHDR`	`Elf32_Phdr`	`Elf64_Phdr`
`ELF_T_REL`	`Elf32_Rel`	`Elf64_Rel`
`ELF_T_RELA`	`Elf32_Rela`	`Elf64_Rela`
`ELF_T_SHDR`	`Elf32_Shdr`	`Elf64_Shdr`
`ELF_T_SWORD`	`Elf32_Sword`	`Elf64_Sword`
`ELF_T_SYM`	`Elf32_Sym`	`Elf64_Sym`
`ELF_T_WORD`	`Elf32_Word`	`Elf64_Word`
`ELF_T_XWORD`		`Elf64_Xword`
`ELF_T_SXWORD`		`Elf64_Sxword`

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

References

Intro(3elf), elf_fsize(3elf), elf_getdata(3elf), elf_getident(3elf)