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elf32.h

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/*!     \file include/kernel/elf32.h
 *      \brief ELF32 file format header.
 *      \author Andrea Righi <drizzt@inwind.it>
 *      \date Last update: 2003-10-01
 *      \note Copyright (&copy;) 2003 Andrea Righi
 */

#ifndef ELF32_H
#define ELF32_H

/** \ingroup Kernel
 *  \defgroup KElf32 ELF32 loader
 *  The loader of the ELF32 format files.
 *  @{
 */

// --- 32-bit ELF address types ----------------------------------------//

typedef uint32_t        Elf32_Addr;
typedef uint16_t        Elf32_Half;
typedef uint32_t        Elf32_Off;
typedef int32_t         Elf32_Sword;
typedef uint32_t        Elf32_Word;

// -- ELF32 header -----------------------------------------------------//

#define EI_NIDENT       16      //!< Size of e_ident[].

//! 32-bit ELF header.
typedef struct elf32_hdr
{
        unsigned char   e_ident[EI_NIDENT];
        Elf32_Half      e_type;
        Elf32_Half      e_machine;
        Elf32_Word      e_version;
        Elf32_Addr      e_entry;
        Elf32_Off       e_phoff;
        Elf32_Off       e_shoff;
        Elf32_Word      e_flags;
        Elf32_Half      e_ehsize;
        Elf32_Half      e_phentsize;
        Elf32_Half      phnum;
        Elf32_Half      e_shentsize;
        Elf32_Half      e_shnum;
        Elf32_Half      e_shstrndx;
} elf32_hdr_t;

#define EI_MAG0         0       //!< File magic number (0).
#define EI_MAG1         1       //!< File magic number (1).
#define EI_MAG2         2       //!< File magic number (2).
#define EI_MAG3         3       //!< File magic number (3)
#define EI_CLASS        4       //!< File class.
#define EI_DATA         5       //!< Data encoding.
#define EI_VERSION      6       //!< File version.
#define EI_PAD          7       //!< Start of padding bytes.

#define ELF_MAG0        0x7F    //!<< ELF magic number.
#define ELF_MAG1        'E'     //!<< ELF magic number[0].
#define ELF_MAG2        'L'     //!< ELF magic number[1].
#define ELF_MAG3        'F'     //!< ELF magic number[2].

// ELF class or capacity                                                //
#define ELF_CLASSNONE   0       //!< Invalid class.
#define ELF_CLASS32     1       //!< 32-bit objects.
#define ELF_CLASS64     2       //!< 64-bit objects.

// ELF data encoding                                                    //
#define ELF_DATANONE    0       //!< Invalid data encoding.
#define ELF_DATA2LSB    1       //!< Least significant byte encoding.
#define ELF_DATA2MSB    2       //!< Most significant byte encoding.

// --- ELF32 Sections --------------------------------------------------//

//! ELF32 Section header.
typedef struct elf32_shdr
{
        Elf32_Word      sh_name;
        Elf32_Word      sh_type;
        Elf32_Word      sh_flags;
        Elf32_Addr      sh_addr;
        Elf32_Off       sh_offset;
        Elf32_Word      sh_size;
        Elf32_Word      sh_link;
        Elf32_Word      sh_info;
        Elf32_Word      sh_addralign;
        Elf32_Word      sh_entsize;
} elf32_shdr_t;

// Section types                                                        //

//! The section is inactive.
#define SHT_NULL        0
//! The section holds informations defined by the program, whose format
//! and meaning are determined solely by the program.
#define SHT_PROGBITS    1
//! The section holds a symbol table.
#define SHT_SYMTAB      2
//! The section holds a string table.
#define SHT_STRTAB      3
//! The section holds relocation entries.
#define SHT_RELA        4
//! The section holds a symbol hash table.
#define SHT_HASH        5
//! The section holds informations for dynamic linking.
#define SHT_DYNAMIC     6
//! The section holds informations that marks the file in some way.
#define SHT_NOTE        7
//! A section of this type occupies no space in the file but otherwise
//! resembles SHT_PROGBITS. Although this section contains no bytes, the
//! \c sh_offset member contains the conceptual file offset.
//! For example the ".bss" section can be considered a section of this
//! type.
#define SHT_NOBITS      8
//! The section holds a relocation entries without explicit addends.
#define SHT_REL         9
//! This section type is reserved, but has unspecified semantics.
#define SHT_SHLIB       10
//! This section contains a set of dynamic linking symbols.
#define SHT_DYNSYM      11
//! Values in this exclusive range are reserved for processor-specific
//! semantics.
#define SHT_LOPROC      0x700000000
//! Values in this exclusive range are reserved for processor-specific
//! semantics.
#define SHT_HIPROC      0x700000000
//! This value specifies the lower bound of the range of indexes
//! reserved for application programs.
#define SHT_LOUSER      0x700000000
//! This value specifies the upper bound of the range of indexes
//! reserved for application programs.
#define SHT_HIUSER      0x700000000

// Section attribute flags                                              //

//! Data should be writable during the process execution.
#define SHF_WRITE       0x1
//! The section occupies memory during the process execution.
#define SHF_ALLOC       0x2
//! The section contains executable machine instructions.
#define SHF_EXECINSTR   0x4
//! All bits included in this mask are reserved for processor-specific
//! semantics.
#define SHF_MASKPROC    0xF00000000

// --- Prototypes ------------------------------------------------------//

uint32_t elf32_copy_sections(elf32_hdr_t *f);
int elf32_load_file(char *file_name, void *file_buffer);
int elf32_exec(void *f, int argc, char **argv);

/** @} */ // end of KElf32

#endif

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