elf.h File Reference

ELF binary loading support. More...

#include <sys/cdefs.h>
#include <arch/types.h>
#include <sys/queue.h>

Go to the source code of this file.

Data Structures
struct	elf_hdr_t
	ELF file header. More...
struct	elf_shdr_t
	ELF Section header. More...
struct	elf_sym_t
	Symbol table entry. More...
struct	elf_rela_t
	ELF Relocation entry (with explicit addend). More...
struct	elf_rel_t
	ELF Relocation entry (without explicit addend). More...
struct	elf_prog
	Kernel-specific definition of a loaded ELF binary. More...

Macros
#define	EM_386   3
	x86 (IA32)
#define	EM_ARM   40
	ARM.
#define	EM_SH   42
	SuperH.
#define	SHT_NULL   0
	Inactive section.
#define	SHT_PROGBITS   1
	Program code/data.
#define	SHT_SYMTAB   2
	Full symbol table.
#define	SHT_STRTAB   3
	String table.
#define	SHT_RELA   4
	Relocation table, with addends.
#define	SHT_HASH   5
	Symbol hash table.
#define	SHT_DYNAMIC   6
	Dynamic linking info.
#define	SHT_NOTE   7
	Notes section.
#define	SHT_NOBITS   8
	A section that occupies no space in the file.
#define	SHT_REL   9
	Relocation table, no addends.
#define	SHT_SHLIB   10
	Reserved.
#define	SHT_DYNSYM   11
	Dynamic-only sym tab.
#define	SHT_LOPROC   0x70000000
	Start of processor specific types.
#define	SHT_HIPROC   0x7fffffff
	End of processor specific types.
#define	SHT_LOUSER   0x80000000
	Start of program specific types.
#define	SHT_HIUSER   0xffffffff
	End of program specific types.
#define	SHF_WRITE   1
	Writable data.
#define	SHF_ALLOC   2
	Resident.
#define	SHF_EXECINSTR   4
	Executable instructions.
#define	SHF_MASKPROC   0xf0000000
	Processor specific mask.
#define	SHN_UNDEF   0
	Undefined, missing, irrelevant.
#define	SHN_ABS   0xfff1
	Absolute values.
#define	STB_LOCAL   0
	Local (non-exported) symbol.
#define	STB_GLOBAL   1
	Global (exported) symbol.
#define	STB_WEAK   2
	Weak-linked symbol.
#define	STT_NOTYPE   0
	Symbol has no type.
#define	STT_OBJECT   1
	Symbol is an object.
#define	STT_FUNC   2
	Symbol is a function.
#define	STT_SECTION   3
	Symbol is a section.
#define	STT_FILE   4
	Symbol is a file name.
#define	ELF32_ST_BIND(info)   ((info) >> 4)
	Retrieve the binding type for a symbol.
#define	ELF32_ST_TYPE(info)   ((info) & 0xf)
	Retrieve the symbol type for a symbol.
#define	R_SH_DIR32   1
	SuperH: Rel = Symbol + Addend.
#define	R_386_32   1
	x86: Rel = Symbol + Addend
#define	R_386_PC32   2
	x86: Rel = Symbol + Addend - Value
#define	ELF32_R_SYM(i)   ((i) >> 8)
	Retrieve the symbol index from a relocation entry.
#define	ELF32_R_TYPE(i)   ((uint8)(i))
	Retrieve the relocation type from a relocation entry.

Typedefs
typedef struct elf_prog	elf_prog_t
	Kernel-specific definition of a loaded ELF binary.

Functions
int	elf_load (const char *fn, struct klibrary *shell, elf_prog_t *out)
	Load an ELF binary.
void	elf_free (elf_prog_t *prog)
	Free a loaded ELF program.

---

Detailed Description

ELF binary loading support.

This file contains the support functionality for loading ELF binaries in KOS. This includes the various header structures and whatnot that are used in ELF files to store code/data/relocations/etc. This isn't necessarily meant for running multiple processes, but more for loadable library support within KOS.

Author:

Dan Potter

---

Macro Definition Documentation

#define ELF32_R_SYM

(

i

)

((i) >> 8)

Retrieve the symbol index from a relocation entry.

Parameters:

i	The info field of an elf_rel_t or elf_rela_t.

Returns:

The symbol table index from that relocation entry.

#define ELF32_R_TYPE

(

i

)

((uint8)(i))

Retrieve the relocation type from a relocation entry.

Parameters:

i	The info field of an elf_rel_t or an elf_rela_t.

Returns:

The relocation type of that relocation.

See also:

ELF relocation types

#define ELF32_ST_BIND

(

info

)

((info) >> 4)

Retrieve the binding type for a symbol.

Parameters:

info	The info field of an elf_sym_t.

Returns:

The binding type of the symbol.

See also:

Symbol binding types.

#define ELF32_ST_TYPE

(

info

)

((info) & 0xf)

Retrieve the symbol type for a symbol.

Parameters:

info	The info field of an elf_sym_t.

Returns:

The symbol type of the symbol.

See also:

Symbol types.

---

Typedef Documentation

typedef struct elf_prog elf_prog_t

Kernel-specific definition of a loaded ELF binary.

This structure represents the internal representation of a loaded ELF binary in KallistiOS (specifically as a dynamically loaded library).

---

Function Documentation

void elf_free

(

elf_prog_t *

prog

)

Free a loaded ELF program.

This function cleans up an ELF binary that was loaded with elf_load().

Parameters:

prog	The loaded binary to clean up.

int elf_load	(	const char *	fn,
		struct klibrary *	shell,
		elf_prog_t *	out
	)

Load an ELF binary.

This function loads an ELF binary from the VFS and fills in an elf_prog_t for it.

Parameters:

fn	The filename of the binary on the VFS.
shell	Unused?
out	Storage for the binary that will be loaded.

Returns:

0 on success, <0 on failure.