2 files changed, 665 insertions, 0 deletions
diff --git a/Master/texmf-dist/source/latex/bitfield/bitfield.dtx b/Master/texmf-dist/source/latex/bitfield/bitfield.dtx
new file mode 100644
index 00000000000..43291f8f656
--- /dev/null
+++ b/Master/texmf-dist/source/latex/bitfield/bitfield.dtx
@@ -0,0 +1,659 @@
+% \iffalse
+%%
+%% File `bitfield.dtx'.
+%% Copyright (C) 1997-2001 Reuben Thomas (rrt@sc3d.org)
+%% Copyright (C) 2001      Roland Illig
+%% This file is distributed under the LaTeX Project Public License,
+%% and comes with no warranty.
+%%
+%
+%<*dtx>
+\ProvidesFile{bitfield.dtx}
+%</dtx>
+%<driver> \ProvidesFile{bitfield.drv}
+% \fi
+%
+% \iffalse
+%<*driver>
+\documentclass{ltxdoc}
+\usepackage{url,dashbox,bitfield}
+\begin{document}
+\DocInput{bitfield.dtx}
+\end{document}
+%</driver>
+% \fi
+%
+% \GetFileInfo{bitfield.dtx}
+% \CheckSum{243}
+%
+% \MakeShortVerb{\|}
+%
+% \changes{v1.00}{1 Mar 97}{First version (unreleased)}
+% \changes{v1.17}{2 Jun 99}{Dashed boxes, stacks and sub-columns
+% added; various bugs fixed}
+% \changes{v1.18}{28 Jul 01}{Made into a doc package; documentation
+% added. At signs inserted into private macro names. Tidied up some
+% infelicities.}
+% \changes{v1.19}{8 Aug 01}{Changed some references to dashbox that
+% should be to bitfield, and changed ``dashdbox'' refs to ``dashbox''
+% to cope with the renaming of that package. Uncommented the commands
+% starting |\NeedsTeXFormat| so they are copied into the package.}
+% \changes{v2.00}{12 Dec 01}{Added the option to have a plain label
+% above the box rather than a rule (thanks to Roland Illig); changed
+% the bit field commands to take a style string rather than having
+% variants of the commands, renamed internal and external commands to
+% start with |bit| rather than |bits|, to avoid confusion. Corrected
+% description of package in |\ProvidesPackage| (it was using that for
+% dashbox!). Made the package require calc 4.1b (to avoid a bug in
+% 4.1a), and the most recent version of dashbox.}
+%
+% \title{Bit field diagrams}
+% \author{Reuben Thomas\\\url{rrt@sc3d.org}\and Roland Illig}
+% \date{12th December 2001}
+% \maketitle
+%
+% \begin{abstract}
+% |bitfield| provides an environment and commands for drawing
+% bit field diagrams, which can be used to describe instruction sets,
+% object code formats, and other bit field based data structures.
+% \end{abstract}
+%
+% \section{User interface}
+%
+% \subsection{Bit field environment}
+%
+% \DescribeEnv{bitfield}
+% Bit field diagrams are drawn in the |bitfield| environment, which
+% takes two arguments. The first, optional argument gives the width of
+% a word (default 4in), and the second the number of bits per word.
+% Each word comprises a number of bit fields, and the words are drawn
+% as a column. Words are ended by |\\|.
+%
+% \DescribeEnv{xbitfield}
+% The |bitfield| environment is actually written in terms of the
+% |xbitfield| environment, which has an extra parameter (the second),
+% giving the left and right margin (the |bitfield| environment uses
+% |\layersize|).
+%
+% \DescribeMacro{\bits}
+% The basic bit field command is |\bits|.
+% |\bits[|\textit{style}|]{|\textit{label}|}{|\textit{bits}|}{|\textit{contents}|}|
+% draws a bit field with the given label, number of bits and contents.
+% The optional argument gives the bit field style, which is a string of
+% flag letters. |d| draws the box dashed, useful for indicating
+% optional structures. and |r| puts the label text in a rule
+% which spans the box.
+%
+% \DescribeMacro{\bitstack}
+% To indicate plurals, for example, where a particular word or data
+% structure may be repeated, |\bitstack| can be used, which produces
+% the appearance of a stack of bit fields. It may only be used once
+% per word (i.e.\ once per line).
+% |\bitstack[|\textit{style}|]{|\textit{label}|}{|\textit{bits}|}{|\textit{contents}|}|
+% draws a stack of width \textit{bits}. The first three arguments are
+% as for |\bits|. The \textit{contents} will typically be a |\bits|
+% command; |\bitstack| itself only draws the stack effect. The
+% enclosed |\bits| should not have a label.
+%
+% For technical reasons, the first bit field on each line is
+% |\fboxrule| narrower than it should be; this should not be
+% noticeable for typical values of |\fboxrule|. (See
+% section~\ref{fudge} for the full story.)
+%
+% \subsection{Alternatives}
+%
+% \DescribeMacro{\bitsub}
+% Sometimes a data structure may have its bit fields divided in
+% different ways according to circumstances, or a particular field may
+% hold one of a small range of values. To show these sorts of
+% alternatives, you can use |\bitsub|, which produces a sub-column of
+% bit fields, vertically centred on the current word.
+% |\bitsub[|\textit{style}|]{|\textit{label}|}{|\textit{bits}|}{|\textit{contents}|}|
+% makes a sub-column of width \textit{bits}. The first three arguments
+% are as for |\bits|, and \textit{contents} is the series of bit
+% fields to go in the column, as if in a |bitfield| environment,
+% separated by |\\|.
+%
+% \DescribeMacro{\bitsubspaced}
+% |\bitsub| draws the alternative bit fields contiguously; to make
+% room for a label on each bit field, use |\bitsubspaced|. 
+% |\bitsubspaced| is the same as |\bitsub|, except that the second
+% argument is omitted; a label can be given as that of the top-most
+% bit field in the contents.
+%
+% \subsection{Helper commands}
+%
+% Some other commands are provided to help draw bit field diagrams.
+% \DescribeMacro{\bitdots} |\bitdots| draws a vertical ellipsis,
+% like |\vdots|, but centred on the column of words.
+% \DescribeMacro{\bittext} |\bittext{|\textit{text}|}| allows text
+% to be inserted between words in a column, adding appropriate
+% vertical spacing.
+%
+% \subsection{Style parameters}
+%
+% There are many style parameters that allow the layout of bit field
+% diagrams to be customised:
+%
+% \begin{itemize}
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitalign}
+%    |\bitalign| gives the alignment within the |bitfield|
+%    environment; defaults to |\centering|.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitboxsep}
+%    |\bitboxsep| is the width of the left and right margins of the
+%    bit field box; defaults to |\fboxsep|.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitboxdepth}
+%    |\bitboxdepth| is the depth of a bit field box; defaults to
+%    0.9ex. 
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitboxheight}
+%    |\bitboxheight| is the height of bit field box; defaults to
+%    3.2ex. 
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitskip}
+%    |\bitskip| is the vertical space between words; defaults to
+%    0.8ex. 
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitrule}
+%    |\bitrule| is the thickness of the label rule; defaults to
+%    |\fboxrule|.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitlabellift}
+%    |\bitlabellift| is the lift of the label above the top of
+%    the box; defaults to 0.4ex.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitruleheight}
+%    |\bitruleheight| is the height of the label rule above the
+%    baseline (top of the box); defaults to 0.6ex.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitruleendlift}
+%    |\bitruleendlift| is the height of the ends of the label
+%    rule above the baseline; defaults to 0.2ex.
+% \end{itemize}
+% \StopEventually{}
+%
+%
+% \section{Example}
+%
+% Here is an example showing most of the features of the |bitfield|
+% package:
+%
+% \begin{center}
+% \begin{bitfield}{32}
+% \bits{31}{1}{s}
+% \bits{30 \hfill 23}{8}{eeeeeeee}
+% \bits{22 \hfill 0}{23}{mmmmmmmmmmmmmmmmmmmmmm} \\
+% \end{bitfield}
+% \end{center}
+%
+% \begin{center}
+% \begin{bitfield}{16}
+% \bits[r]{sixteen}{16}{16 bits wide}\\
+% \bits[d]{}{4}{optional}\bitstack{}{4}{\bits{}{4}{many}}\\
+% \bits[r]{}{8}{fixed}%
+%   \bitsubspaced{8}{\bits{}{8}{optional 1}\\\bits{}{8}{optional 2}}\\
+% \end{bitfield}
+% \end{center}
+%
+%
+% \section{Implementation}
+%
+% \subsection{Preliminaries}
+%
+% Make sure we've got what we need, and announce the package.
+%
+%    \begin{macrocode}
+%<*package>
+\NeedsTeXFormat{LaTeX2e}
+\ProvidesPackage{bitfield}[2001/12/12 v2.00 Bit field diagrams]
+\RequirePackage{dashbox}[2001/12/11]
+\RequirePackage{calc}[1998/07/07]
+\RequirePackage{ifthen}
+%    \end{macrocode}
+%
+% \subsection{Style parameters}
+%
+% Define and give the default values of the style parameters.
+%
+% \begin{macro}{\bitalign}
+%    \begin{macrocode}
+\newcommand{\bitalign}{\centering}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitboxsep}
+%    \begin{macrocode}
+\newlength{\bitboxsep} \setlength{\bitboxsep}{\fboxsep}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitboxdepth}
+%    \begin{macrocode}
+\newlength{\bitboxdepth} \setlength{\bitboxdepth}{0.9ex}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitboxheight}
+%    \begin{macrocode}
+\newlength{\bitboxheight} \setlength{\bitboxheight}{3.2ex}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitskip}
+%    \begin{macrocode}
+\newlength{\bitskip} \setlength{\bitskip}{0.8ex}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitrule}
+%    \begin{macrocode}
+\newlength{\bitrule} \setlength{\bitrule}{\fboxrule}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitlabellift}
+%    \begin{macrocode}
+\newlength{\bitlabellift} \setlength{\bitlabellift}{0.4ex}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitruleheight}
+%    \begin{macrocode}
+\newlength{\bitruleheight} \setlength{\bitruleheight}{0.6ex}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitruleendlift}
+%    \begin{macrocode}
+\newlength{\bitruleendlift} \setlength{\bitruleendlift}{0.2ex}
+%    \end{macrocode}
+% \end{macro}
+%
+% In addition, define some private variables:
+%
+% \begin{itemize}
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitw@dth}
+%    |\bitw@dth| is the width of a bit in the current word.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitb@xwidth}
+%    |\bitb@xwidth| is the width of the current field, excluding
+%    margins.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitw@dthwidth}
+%    |\bitw@dthwidth| is the width of the label rule.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitruled@pth}
+%    |\bitruled@pth| is  the depth of the label rule, which is
+%    the thickness minus the height.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitrule@ndheight}
+%    |\bitrule@ndheight| is the height of the ends of the rule.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{bitb@xfirst}
+%    |bitb@xfirst| is a boolean that is true when the first bit field
+%    in a word is being set.
+% \item[]\hskip-\leftmargin
+% \DescribeMacro{\bitb@x}
+%    |\bitb@x| is a save box used to hold a bitfield while the rule
+%    is being added.
+% \end{itemize}
+%
+% \begin{macro}{\bitw@dth}
+%    \begin{macrocode}
+\newlength{\bitw@dth}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitb@xwidth}
+%    \begin{macrocode}
+\newlength{\bitb@xwidth}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitw@dthwidth}
+%    \begin{macrocode}
+\newlength{\bitw@dthwidth}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitruled@pth}
+%    \begin{macrocode}
+\newlength{\bitruled@pth}
+    \setlength{\bitruled@pth}{\bitrule-\bitruleheight}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitrule@ndheight}
+%    \begin{macrocode}
+\newlength{\bitrule@ndheight}
+    \setlength{\bitrule@ndheight}%
+    {\bitruleheight*2-\bitrule-\bitruleendlift*2}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{bitb@xfirst}
+%    \begin{macrocode}
+\newboolean{bitb@xfirst}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitb@x}
+%    \begin{macrocode}
+\newsavebox{\bitb@x}
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{Internal commands}
+%
+% Some internal helper commands are defined first.
+%
+% \begin{macro}{\bitdec@destyle}
+% |\bitdec@destyle| decodes a style string. Three commands are set
+% up: |\bitb@xcmd|, to draw the box, |\bitst@ckcmd|, to draw a bit
+% stack box, and |\bitl@belcmd|, to draw a label.
+%
+%    \begin{macrocode}
+\newcommand{\bitb@xcmd}{\framebox}%
+\newcommand{\bitst@ckcmd}{\lbox}%
+\newcommand{\bitl@belcmd}{\bitl@bel}%
+\newcommand{\bitdec@destyle}[1]{%
+%    \end{macrocode}
+%
+% First, the commands are initialised with their default values.
+%
+%    \begin{macrocode}
+    \renewcommand{\bitb@xcmd}{\framebox}%
+    \renewcommand{\bitst@ckcmd}{\lbox}%
+    \renewcommand{\bitl@belcmd}{\bitpl@inlabel}%
+%    \end{macrocode}
+%
+% The style string is then scanned, and the commands altered
+% accordingly. The code here is adapted from that for the
+% picture version of |\makebox|.
+%
+%    \begin{macrocode}
+    \@tfor\reserved@a :=#1\do{%
+      \if d\reserved@a
+            \renewcommand{\bitb@xcmd}{\dashbox}%
+            \renewcommand{\bitst@ckcmd}{\dlbox}%
+        \else
+            \if r\reserved@a%
+                \renewcommand{\bitl@belcmd}{\bitrulel@bel}%
+            \fi
+        \fi}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitle@der}
+% |\bitle@der| produces the middle sections of label rules.
+%
+%    \begin{macrocode}
+\newcommand{\bitle@der}{%
+    \cleaders\hrule height \bitruleheight depth \bitruled@pth%
+    \hfill}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitpl@inlabel}
+% |\bitpl@inlabel| draws a label over a bit field box. The first argument
+% gives the width of the label, and the second the label text. The
+% label text is set at |\footnotesize|.
+%
+%    \begin{macrocode}
+\newcommand{\bitpl@inlabel}[2]{%
+    \makebox[#1]{\footnotesize #2}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitrulel@bel}
+% |\bitrulel@bel| draws a label with a rule. The first argument gives
+% the width, and the second the text to go in the middle.
+%
+%    \begin{macrocode}
+\newcommand{\bitrulel@bel}[2]{%
+%    \end{macrocode}
+%
+% The rule is typeset in a box of the given width
+%
+%    \begin{macrocode}
+    \makebox[#1]{%
+%    \end{macrocode}
+%
+% The label text is set at |\footnotesize|; the left-hand end is drawn,
+% followed by the left-hand horizontal, then a thin space, the
+% contents, another thin space, the right-hand horizontal, and finally
+% the right-hand end.
+%
+%    \begin{macrocode}
+        \footnotesize%
+        \rule[\bitruleendlift]{\bitrule}{\bitrule@ndheight}%
+        \bitle@der\,#2\,\bitle@der%
+        \rule[\bitruleendlift]{\bitrule}{\bitrule@ndheight}}%
+    }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitl@bel}
+% |\bitl@bel| labels a bit field box. The first, optional, argument
+% gives an increment to add to the width of the label; this is used
+% for drawing stacks. The second argument gives the label text; the
+% third is the width of the box in bits, and the fourth is the box
+% itself.
+%
+%    \begin{macrocode}
+\newcommand{\bitl@bel}[4][0pt]{%
+%    \end{macrocode}
+%
+% The bit field box is saved.
+%
+%    \begin{macrocode}
+    \sbox{\bitb@x}{#4}%
+%    \end{macrocode}
+%
+% |\bitw@dthwidth| is calculated from the size of the box; the first
+% argument, if any, is added to it.
+%
+%    \begin{macrocode}
+     \setlength{\bitw@dthwidth}{\wd\bitb@x-\bitboxsep*2-\fboxrule*2}%
+     \addtolength{\bitw@dthwidth}{#1}%
+%    \end{macrocode}
+%
+% The label is drawn in a zero-width box, so that it takes up no space,
+% to avoid formatting problems.
+%
+%    \begin{macrocode}
+     \ifthenelse{\equal{#2}{}}{\relax}{\makebox[0pt][l]{%
+%    \end{macrocode}
+%
+% The label is raised by |\bitlabellift|, and the given horizontal
+% margin is left.
+%
+%    \begin{macrocode}
+         \raisebox{\ht\bitb@x}{\raisebox{\bitlabellift}{%
+             {\hspace*{\fboxrule}\hspace*{\bitboxsep}%
+%    \end{macrocode}
+%
+% The label is drawn.
+%
+%    \begin{macrocode}
+             \bitl@belcmd{\bitw@dthwidth}{#2}%
+         }}}}}%
+%    \end{macrocode}
+%
+% The box is now drawn underneath.
+%
+%    \begin{macrocode}
+    \usebox{\bitb@x}%
+    }%
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\m@kebits}
+% |\m@kebits| draws a bit field box. The arguments are the label
+% text, the number of bits in the field, and the contents of the field.
+%
+%    \begin{macrocode}
+\newcommand{\m@kebits}[3]{%
+%    \end{macrocode}
+%
+% |\bitb@xwidth| is set; the length is incremented by |\fboxrule| if
+% this box is not the first on the current line. This is because the
+% first box has two sides drawn; the rest only have the right-hand
+% side (subsequent box's left-hand sides overlap with the previous
+% box's right-hand side). |bitb@xfirst| is set to |false|, as the
+% next box cannot be the first!
+%
+%    \begin{macrocode}
+    \setlength{\bitb@xwidth}{\bitw@dth*#2}%
+    \ifthenelse{\boolean{bitb@xfirst}}%
+        {}%
+        {\addtolength{\bitb@xwidth}{\fboxrule}}%
+    \setboolean{bitb@xfirst}{false}%
+%    \end{macrocode}
+%
+% |\fboxsep| is locally set to 0pt, and the label and box are drawn.
+% The contents of the box is centred, and a margin of |\bitboxsep| is
+% left around it. 
+%
+%    \begin{macrocode}
+    \setlength{\fboxsep}{0pt}%
+    \bitl@bel{#1}{#2}{\bitb@xcmd[\bitb@xwidth]%
+        {\rule[-\bitboxdepth]{0pt}{\bitboxheight}%
+        \hspace*{\bitboxsep}\hfill#3\hfill\hspace*{\bitboxsep}}%
+%    \end{macrocode}
+%
+% A negative space is left so that the next box's left-hand side
+% overlaps with this box's right-hand side.
+%
+%    \begin{macrocode}
+    \hspace*{-\fboxrule}}%
+    }
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\m@kestack}
+% |\m@kestack| draws a bit field stack; it takes the same arguments as
+% |\m@kebits|.
+%
+%    \begin{macrocode}
+\newcommand{\m@kestack}[3]{%
+    \setlength{\fboxsep}{0pt}%
+    \bitl@bel[-2\layersize]{#1}{#2}{\bitst@ckcmd{#3\hspace*{\fboxrule}}}%
+    }
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{User commands}
+%
+% Most of the user commands are just wrappers for the internal
+% commands.
+%
+% \begin{macro}{\bits}
+%    \begin{macrocode}
+\newcommand{\bits}[4][]{%
+    \bitdec@destyle{#1}%
+    \m@kebits{#2}{#3}{#4}}
+%    \end{macrocode}
+% \end{macro}
+% \begin{macro}{\bitstack}
+%    \begin{macrocode}
+\newcommand{\bitstack}[4][]{%
+    \bitdec@destyle{#1}%
+    \m@kestack{#2}{#3}{#4}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitsubspaced}
+% |\bitsubspaced| sets its third argument in an |xbitfield|
+% environment with 0pt margins and no alignment, and ends with the
+% same negative kern as |\bits|.
+%
+%    \begin{macrocode}
+\newcommand{\bitsubspaced}[3][]{%
+    \bitdec@destyle{#1}%
+    \renewcommand{\bitalign}{\relax}%
+    \begin{xbitfield}[#2\bitw@dth]{0pt}{#2}#3\end{xbitfield}%
+    \hspace*{-\fboxrule}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \label{fudge}
+% \begin{macro}{\bitsub}
+% |\bitsub| is written using |\bitsubspaced| by changing |\bitskip| to
+% $-$|\fboxrule|, so that the boxes overlap vertically in the same way
+% that bit fields normally do horizontally. Note the extra level of
+% bracketing so that the |\setlength| has only a local effect.
+%
+%    \begin{macrocode}
+\newcommand{\bitsub}[4][]{%
+    {\setlength{\bitskip}{-\fboxrule}%
+    \bitl@bel{#2}{#3}{\bitsubspaced[#1]{#3}{#4}}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bitdots}
+% |\bitdots| simply draws a centred vertical ellipsis, 2.5ex high,
+% centred in a parbox of width |\textwidth|.
+%
+%    \begin{macrocode}
+\newcommand{\bitdots}{%
+    \parbox{\textwidth}{%
+        \centering\vbox to 2.5ex{%
+            \cleaders\vbox to 0.8ex{\vfill.\vfill}\vfill}}}
+%    \end{macrocode}
+% \end{macro}
+%
+% \begin{macro}{\bittext}
+% |\bittext| draws a zero-width rule of the correct height and depth
+% for a box next to the given text.
+%
+%    \begin{macrocode}
+\newcommand{\bittext}[1]{%
+    \rule[-\bitboxdepth]{0pt}{\bitboxheight}#1}
+%    \end{macrocode}
+% \end{macro}
+%
+% \subsection{The environments}
+%
+% \begin{environment}{xbitfield}
+% The |xbitfield| environment provides the innards of the |bitfield|
+% environment. It provides a little extra customization, by means of
+% its second argument, which gives the left and right margin. The
+% other two arguments are as for the |bitfield| environment.
+%
+%    \begin{macrocode}
+\newenvironment{xbitfield}[3][4in]%
+%    \end{macrocode}
+%
+% First, |\bitw@dth| is calculated.
+%
+%    \begin{macrocode}
+    {\setlength{\bitw@dth}{(#1-#2*2)/#3}%
+%    \end{macrocode}
+%
+% The words are set in a minipage; the alignment is set according to
+% |\bitalign|, and inter-line spacing is turned off, so that only the
+% bit field layout parameters affect the result. |\endlinechar| is set
+% to $-1$ so that blank lines do not start a new paragraph. |\\| is
+% redefined to set |bitb@xfirst| to |true| as well as ending the
+% line, and |bitb@xfirst| is set to |true|.
+%
+%    \begin{macrocode}
+    \begin{minipage}{#1}\bitalign%
+    \offinterlineskip%
+    \endlinechar=-1%
+    \renewcommand{\\}%
+        {\par\vspace{\bitskip}\setboolean{bitb@xfirst}{true}}%
+    \setboolean{bitb@xfirst}{true}%
+    }%
+%    \end{macrocode}
+%
+% At the end of the environment, the minipage is closed, and
+% |bitb@xfirst| is set to |false| in case a |\bits| command is used
+% outside a |bitfield| environment (though that is not recommended).
+%    \begin{macrocode}
+    {\end{minipage}%
+    \setboolean{bitb@xfirst}{false}}
+%    \end{macrocode}
+% \end{environment}
+%
+% \begin{environment}{bitfield}
+% The |bitfield| environment simply invokes the |xbitfield|
+% environment with a margin of |\layersize|.
+%
+%    \begin{macrocode}
+\newenvironment{bitfield}[2][4in]%
+    {\begin{xbitfield}[#1]{\layersize}{#2}}%
+    {\end{xbitfield}}
+%    \end{macrocode}
+% \end{environment}
diff --git a/Master/texmf-dist/source/latex/bitfield/bitfield.ins b/Master/texmf-dist/source/latex/bitfield/bitfield.ins
new file mode 100644
index 00000000000..bc105407bc1
--- /dev/null
+++ b/Master/texmf-dist/source/latex/bitfield/bitfield.ins
@@ -0,0 +1,6 @@
+\def\batchfile{bitfield.ins}
+\input docstrip.tex
+\preamble
+   Dashed and layered boxes.
+\endpreamble
+\generateFile{bitfield.sty}   {t}{\from{bitfield.dtx}{package}}