project/captive/doc/About.html.pl

   1 #! /usr/bin/perl
   2 #
   3 # $Id$
   4 # Captive project doc About page Perl template.
   5 # Copyright (C) 2003 Jan Kratochvil <project-www.jankratochvil.net@jankratochvil.net>
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; exactly version 2 of June 1991 is required
  10 #
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program; if not, write to the Free Software
  18 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19
  20
  21 package project::captive::doc::About;
  22 require 5.6.0;  # at least 'use warnings;' but we need some 5.6.0+ modules anyway
  23 our $VERSION=do { my @r=(q$Revision$=~/\d+/g); sprintf "%d.".("%03d"x$#r),@r; };
  24 our $CVS_ID=q$Id$;
  25 use strict;
  26 use warnings;
  27
  28 BEGIN{ open F,"Makefile"; our $top_dir=pop @{[split /\s/,(grep /^top_srcdir/,<F>)[0]]}; eval "use lib '$top_dir'"; close F; }
  29 use My::Web;
  30 require CGI;
  31 BEGIN { Wuse 'project::captive::doc::Macros'; }
  32
  33
  34 project::captive::doc::Macros->init(
  35                 "__PACKAGE__"=>__PACKAGE__,
  36                 "title"=>'Captive NTFS Developer Documentation: About',
  37                 "rel_prev"=>'Index.html.pl',
  38                 "rel_next"=>'Architecture.html.pl',
  39                 );
  40
  41
  42 print <<"HERE";
  43
  44
  45 <h1>About</h1>
  46
  47         <a name="reasons"><h2>Reasons for the Implementation</h2></a>
  48
  49                 <p>Currently there is no possibility to any of the available $freespeech
  50                         ($freespeech used in the following text in the meaning of
  51                         &quot;@{[ a_href 'http://www.gnu.org/philosophy/free-sw.html','free as in speech' ]}&quot;)
  52                 operating systems to reliably write to the most common disk partition
  53                 filesystem type &ndash; <span class="productname">Microsoft NTFS</span>. It would
  54                 be already supported a long time ago but there is no proper documentation of
  55                 <span class="productname">NTFS</span> filesystem data structures available.
  56                 Since <span class="productname">Microsoft</span> corporation continues in its
  57                 propagation of <span class="productname">Microsoft Windows NT</span>
  58                         (<span class="productname">NT</span> identifier used in the following text
  59                         applies to all the products of <span class="productname">Microsoft</span>
  60                         <span class="productname">NT</span> series such as
  61                         <span class="productname">NT&nbsp;4.0</span>,
  62                         <span class="productname">2000</span> as NT-5.0
  63                         and
  64                         <span class="productname">XP</span> as NT-5.1.)
  65                 based operating systems <span class="productname">NTFS</span> is the default
  66                 disk file system type for vendor preinstalled <span class="productname">Microsoft Windows</span>.
  67
  68                 <p>Unfortunately the <span class="productname">NTFS</span> filesystem has too
  69                 complex data structure to allow a complete reverse enginnering process in
  70                 reasonable time. Currently available $freespeech solutions such as $LinuxNTFS
  71                 filesystem have already implemented reliable reverse
  72                 engineered read-only access. However <a name="reliability">reliabile</a>
  73                 read-write part of the access would require much better
  74                 knowledge of the <span class="productname">NTFS</span> data structures.
  75                 Currently only rewriting of already existing file data blocks is supported
  76                 by $LinuxNTFS &mdash; no file creation, no file deletion, no directory operations etc.
  77                 Also any future versions of <span class="productname">NTFS</span> filesystem
  78                 would require another major reverse engineering effort.</p>
  79
  80
  81         <a name="challenges"><h2>Challenges of the Project</h2></a>
  82
  83                 <p>The <a name="NTFSgoal">ultimate goal</a> of this project is definitely the
  84                 free implementation of @{[ a_href '#reliability','reliable' ]} read-write <span
  85                 class="productname">NTFS</span> filesystem driver. This project chose to
  86                 solve this problem in the style of $Wine project by using the original binary
  87                 <span class="fname">ntfs.sys</span> and emulating all the required layers of
  88                 <span class="productname">Microsoft Windows NT</span> for it.</p>
  89
  90                 <p>Unfortunately this effort is tainted by only partial and generally
  91                 insufficient documentation of API between filesystem driver
  92                 (<span class="fname">ntfs.sys</span>) and the
  93                 <span class="productname">Microsoft Windows NT</span>
  94                 (&quot;@{[ a_href 'http://mail.gnu.org/archive/html/libtool/2000-09/msg00000.html','W32' ]}&quot;
  95                 in the following text) kernel <span class="fname">ntoskrnl.exe</span>. Note
  96                 that this API is a different than the one being used in the $Wine project
  97                 since <span class="productname">Wine</span> implements only the user space
  98                 part of W32.</p>
  99
 100
 101         <a name="versions"><h2>Microsoft Windows Versions Compatibility</h2></a>
 102
 103                 <p>Currently this project supports only driver files of
 104                 <span class="productname">Microsoft Windows XP</span> (NT-5.1)
 105                 in the following releases:</p>
 106
 107                 <ul>
 108                         <li>Microsoft Windows XP Service Pack 1a Checked Build U.S.</li>
 109                         <li>Microsoft Windows XP Service Pack 1a Free Build U.S.</li>
 110                         <li>Microsoft Windows XP (No Service Pack) Checked Build U.S.</li>
 111                         <li>Microsoft Windows XP (No Service Pack) Free Build U.S.</li>
 112                 </ul>
 113
 114                 <p>The latest list of supported driver files can be found in:
 115                 @{[ captive_srcfile 'src/install/acquire/w32-mod-id.captivemodid.xml' ]}</p>
 116
 117                 <p>Microsoft Windows NTFS filesystem driver is capable of accessing even
 118                 the older formats of the filesystem. Porting to Microsoft Windows 2003
 119                 Server is expected to be done soon. There can be also a danger of Microsoft
 120                 Windows upgrading NTFS disk filesystem where you would no longer be able
 121                 to access your NTFS disk by your original
 122                 <span class="productname">Microsoft Windows</span> version.
 123                 This upgrade does not happen as it occurs only during complete CD-ROM
 124                 Microsoft Windows system installation &ndash; such operation is not performed
 125                 by this project.</p>
 126
 127                 <p>There is no problem technically obtaining the needed driver files of
 128                 <span class="productname">Microsoft Windows XP</span> as they are freely
 129                 downloadable at:
 130                 @{[ a_href 'http://www.microsoft.com/WindowsXP/pro/downloads/servicepacks/sp1/checkedbuild.asp' ]}</p>
 131                 There may be @{[ a_href 'Architecture.html.pl#law','legal reasons' ]} you would not be allowed
 132                 to use there files if you own license to a different version of
 133                 <span class="productname">Microsoft Windows</span>. Legal rights will very
 134                 depending on your country.</p>
 135
 136
 137 HERE
 138
 139
 140 project::captive::doc::Macros->footer();