ELFIO/examples/writer/writer.cpp

#include <elfio/elfio.hpp>

using namespace ELFIO;

int main( void )
{
    elfio writer;

    // You can't proceed without this function call!
    writer.create( ELFCLASS64, ELFDATA2LSB );

    writer.set_os_abi( ELFOSABI_LINUX );
    writer.set_type( ET_EXEC );
    writer.set_machine( EM_X86_64 );

    // Create code section
    section* text_sec = writer.sections.add( ".text" );
    text_sec->set_type( SHT_PROGBITS );
    text_sec->set_flags( SHF_ALLOC | SHF_EXECINSTR );
    text_sec->set_addr_align( 0x10 );

    // Add data into it
    char text[] = {
        '\xB8', '\x04', '\x00', '\x00', '\x00', // mov eax, 4
        '\xBB', '\x01', '\x00', '\x00', '\x00', // mov ebx, 1
        '\xB9', '\x20', '\x80', '\x04', '\x08', // mov ecx, msg
        '\xBA', '\x0E', '\x00', '\x00', '\x00', // mov edx, 14
        '\xCD', '\x80',                         // int 0x80
        '\xB8', '\x01', '\x00', '\x00', '\x00', // mov eax, 1
        '\xCD', '\x80'                          // int 0x80
    };
    text_sec->set_data( text, sizeof( text ) );

    // Create a loadable segment
    segment* text_seg = writer.segments.add();
    text_seg->set_type( PT_LOAD );
    text_seg->set_virtual_address( 0x08048000 );
    text_seg->set_physical_address( 0x08048000 );
    text_seg->set_flags( PF_X | PF_R );
    text_seg->set_align( 0x1000 );

    // Add code section into program segment
    text_seg->add_section_index( text_sec->get_index(),
                                 text_sec->get_addr_align() );

    // Create data section
    section* data_sec = writer.sections.add( ".data" );
    data_sec->set_type( SHT_PROGBITS );
    data_sec->set_flags( SHF_ALLOC | SHF_WRITE );
    data_sec->set_addr_align( 0x4 );

    char data[] = {
        '\x48', '\x65', '\x6C', '\x6C', '\x6F', // msg: db   'Hello, World!', 10
        '\x2C', '\x20', '\x57', '\x6F', '\x72',
        '\x6C', '\x64', '\x21', '\x0A' };
    data_sec->set_data( data, sizeof( data ) );

    // Create a read/write segment
    segment* data_seg = writer.segments.add();
    data_seg->set_type( PT_LOAD );
    data_seg->set_virtual_address( 0x08048020 );
    data_seg->set_physical_address( 0x08048020 );
    data_seg->set_flags( PF_W | PF_R );
    data_seg->set_align( 0x10 );

    // Add code section into program segment
    data_seg->add_section_index( data_sec->get_index(),
                                 data_sec->get_addr_align() );

    // Add optional signature for the file producer
    section* note_sec = writer.sections.add( ".note" );
    note_sec->set_type( SHT_NOTE );
    note_sec->set_addr_align( 1 );
    note_section_accessor note_writer( writer, note_sec );
    note_writer.add_note( 0x01, "Created by ELFIO", 0, 0 );
    char descr[6] = { 0x31, 0x32, 0x33, 0x34, 0x35, 0x36 };
    note_writer.add_note( 0x01, "Never easier!", descr, sizeof( descr ) );

    // Setup entry point
    writer.set_entry( 0x08048000 );

    // Create ELF file
    writer.save( "hello_x86_64" );

    return 0;
}