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6502bench/docs/sgtutorial/inline-data.html
Andy McFadden a37143e9fc Execute scripts
This change applies the substitution scripts on the HTML files,
replacing away the jQuery load() calls with the actual file contents,
and setting the correct URLs to the prev/next buttons.
2021-06-07 17:14:16 -07:00

185 lines
6.8 KiB
HTML

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"
integrity="sha384-vtXRMe3mGCbOeY7l30aIg8H9p3GdeSe4IFlP6G8JMa7o7lXvnz3GFKzPxzJdPfGK" crossorigin="anonymous"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css"/>
<link rel="stylesheet" href="/main.css"/>
<title>Inline Data - SourceGen Tutorial</title>
</head>
<body>
<div id="masthead">
<!-- START: /masthead-incl.html -->
<!--<div class="masthead-title" style="background-image: url('images/screenshot-mainwin.png');">-->
<div class="masthead-title">
6502bench
</div>
<!-- END: /masthead-incl.html -->
</div>
<div id="topnav">
<!-- START: /topnav-incl.html active:#topnav-sgtutorial -->
<!-- top navigation bar contents -->
<nav>
<a id="topnav-home" href="/">HOME</a>
<a id="topnav-sgtutorial" class="active" href="/sgtutorial">SourceGen Tutorial</a>
<a id="topnav-menuicon" href="javascript:void(0);" class="icon" onclick="toggleSidenav()">
<i class="fa fa-bars"></i>
</a>
</nav>
<script>
// If page has no sidenav, don't show the sidenav toggle button.
if (document.getElementById("sidenav") == undefined) {
$("#topnav-menuicon").hide();
}
// Sidenav toggle function.
//
// Use a jQuery function to toggle the sidenav bar. The initial state
// is undefined / inherited, so it will pop in and out as the screen
// resizes around the "large" breakpoint.
function toggleSidenav() {
$("#sidenav").toggle("fast");
}
</script>
<!-- END: /topnav-incl.html -->
</div>
<div id="sidenav">
<!-- START: sidenav-incl.html active:#sidenav-inline-data -->
<!-- side navigation bar contents -->
<ul>
<li id="sidenav-index"><a href="./">Introduction</a></li>
<li id="sidenav-about-disasm"><a href="about-disasm.html">About Disassembly</a></li>
<li id="sidenav-using-sourcegen"><a href="using-sourcegen.html">Using SourceGen</a></li>
<ul>
<li id="sidenav-moving-around"><a href="moving-around.html">Moving Around</a></li>
<li id="sidenav-simple-edits"><a href="simple-edits.html">Simple Edits</a></li>
<li id="sidenav-labels-symbols"><a href="labels-symbols.html">Labels &amp; Symbols</a></li>
<li id="sidenav-editing-data"><a href="editing-data.html">Editing Data Operands</a></li>
<li id="sidenav-generating-code"><a href="generating-code.html">Generating Code</a></li>
</ul>
<li id="sidenav-digging-deeper"><a href="digging-deeper.html">Digging Deeper</a></li>
<ul>
<li id="sidenav-string-formatting"><a href="string-formatting.html">String Formatting</a></li>
<li id="sidenav-local-variables"><a href="local-variables.html">Local Variables</a></li>
<li id="sidenav-inline-data" class="active"><a href="inline-data.html">Inline Data</a></li>
<li id="sidenav-odds-ends"><a href="odds-ends.html">Odds &amp; Ends</a></li>
</ul>
<li id="sidenav-advanced-topics"><a href="advanced-topics.html">Advanced Topics</a></li>
<ul>
<li id="sidenav-address-tables"><a href="address-tables.html">Address Tables</a></li>
<li id="sidenav-extension-scripts"><a href="extension-scripts.html">Extension Scripts</a></li>
<li id="sidenav-visualizations"><a href="visualizations.html">Visualizations</a></li>
</ul>
</ul>
<!-- END: sidenav-incl.html -->
</div>
<div id="main">
<h2>Inline Data</h2>
<div class="grid-container">
<div class="grid-item-image">
<img src="images/t2-206b.png" alt="t2-206b"/>
</div>
<div class="grid-item-text">
<p>Consider the code at address $206B. It's a <code>JSR</code> followed by some
ASCII text, then a $00 byte, and then what might be code.</p>
</div>
</div>
<div class="grid-container">
<div class="grid-item-image">
<img src="images/t2-20ab-1.png" alt="t2-20ab-1"/>
<br/>
...
<br/>
<img src="images/t2-20ab-2.png" alt="t2-20ab-2"/>
</div>
<div class="grid-item-text">
<p>Double-click on the <code>JSR</code> opcode
to jump to $20AB to see the function. It pulls the
call address off the stack, and uses it as a pointer. When it encounters
a zero byte, it breaks out of the loop, pushes the adjusted pointer
value back onto the stack, and returns.</p>
</div>
</div>
<div class="grid-container">
<div class="grid-item-text">
<p>This is an example of "inline data", where a function uses the return
address to get a pointer to data. The return address is adjusted to
point past the inline data before returning (technically, it points at
the very last byte of the inline data, because
<code>RTS</code> jumps to address + 1).</p>
</div>
</div>
<div class="grid-container">
<div class="grid-item-image">
<img src="images/t2-inline-tag.png" alt="t2-inline-tag"/>
</div>
<div class="grid-item-text">
<p>To format the data, we first need to tell SourceGen that there's data
in line with the code. Select the line at address $206E, then
shift-click the line at address $2077. Use
<samp>Actions &gt; Tag Bytes As Inline Data</samp>
(<kbd class="key">Ctrl+H</kbd><kbd class="key">Ctrl+I</kbd>).</p>
</div>
</div>
<div class="grid-container">
<div class="grid-item-image">
<img src="images/t2-inline-after.png" alt="t2-inline-after"/>
</div>
<div class="grid-item-text">
<p>The data turns to single-byte values, and we now see the code
continuing at address $2078. We can format the data as a string by
using <samp>Actions &gt; Edit Operand</samp>,
setting the Character Encoding to <samp>Low or High ASCII</samp>,
and selecting <samp>null-terminated strings</samp>.</p>
</div>
</div>
<div class="grid-container">
<div class="grid-item-text">
<p>That's pretty straightforward, but this could quickly become tedious if
there were a lot of these. SourceGen allows you to define scripts to
automate common formatting tasks. This is covered in the "Extension
Scripts" tutorial.</p>
</div>
</div>
</div> <!-- #main -->
<div id="prevnext">
<a href="local-variables.html" class="btn-previous">&laquo; Previous</a>
<a href="odds-ends.html" class="btn-next">Next &raquo;</a>
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