NAME

Disassemble::X86::MemRegion - Represent a region of memory

SYNOPSIS

  use Disassemble::X86::MemRegion;
  my $mem = Disassemble::X86::MemRegion->new( mem => $data );
  print $mem->get_string($pos), "\n";

DESCRIPTION

Represents a region of memory. Provides methods for extracting parts of the memory. Since this module is designed with the Intel x86 architecture in mind, it uses the little-endian byte ordering wherever appropriate.

METHODS

new

  $mem = Disassemble::X86::MemRegion->new(
      mem   => $data,
      start => $addr,
  );

Create a new memory region object. The mem parameter is a scalar value which gives the contents of the memory region. If the optional start parameter is present, it gives the starting address of the region. Otherwise, 0 is used.

mem

  $data = $mem->mem();

Returns the contents of the memory region as a single scalar value.

start

  $start = $mem->start();

Returns the starting address of the region.

end

  $end = $mem->end();

Returns the ending address of the region, which is one plus the last valid address.

contains

  if ( $mem->contains($addr) ) {
    ...
  }

Returns true if the given address is within the memory region.

get_byte

  $val = $mem->get_byte($pos);

Returns a byte from position $pos as an integer value. Returns undef if position is invalid.

get_word

  $val = $mem->get_word($pos);

Returns a 2-byte little-endian integer from $pos, or undef if position is invalid.

get_long

  $val = $mem->get_long($pos);

Returns a 4-byte little-endian integer from $pos, or undef if position is invalid.

get_string

  $str = $mem->get_string($pos, $maxlen);

Extracts and returns a null-terminated (C style) string from the memory region starting at position $pos. The null terminator is not included in the return value. Returns undef if the starting position is outside the memory region. The $maxlen parameter is optional. If present, it gives the maximum length of the string returned.

get_string_lenbyte

  $str = $mem->get_string_lenbyte($pos);

Fetches a single byte from memory address $pos. Using that as a length byte, extracts and returns a string containing that many bytes. Returns undef if position is invalid.

get_string_lenword

  $str = $mem->get_string_lenword($pos);

Fetches a two-byte little-endian word starting at $pos. Extracts and returns a string containing that many bytes. Returns undef if position is invalid.

LIMITATIONS

Memory is read-only.

The entire memory region must be present in memory.

SEE ALSO

the Disassemble::X86 manpage

AUTHOR

Bob Mathews <bobmathews@alumni.calpoly.edu>

COPYRIGHT

Copyright (c) 2002 Bob Mathews. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.