mirror of
https://github.com/fadden/6502bench.git
synced 2024-09-06 01:55:11 +00:00
Fairly straightfoward in Python. Also, fixed the sidenav references, which should be using the file in the sgtutorial subdirectory. Also, tweaked index.html a bit.
137 lines
4.7 KiB
HTML
137 lines
4.7 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 -->
|
|
<script>$("#masthead").load("/masthead-incl.html");</script>
|
|
<!-- END: /masthead-incl.html -->
|
|
</div>
|
|
|
|
<div id="topnav">
|
|
<!-- START: /topnav-incl.html active:#topnav-sgtutorial -->
|
|
<script>
|
|
// Load global topnav content, and mark current page active.
|
|
$("#topnav").load("/topnav-incl.html", function() {
|
|
$("#topnav-sgtutorial").addClass("active");
|
|
});
|
|
</script>
|
|
<!-- END: /topnav-incl.html -->
|
|
</div>
|
|
|
|
<div id="sidenav">
|
|
<!-- START: sidenav-incl.html active:#sidenav-inline-data -->
|
|
<script>
|
|
// Load local sidenav content, and mark current page active.
|
|
$("#sidenav").load("sidenav-incl.html", function() {
|
|
$("#sidenav-inline-data").addClass("active");
|
|
});
|
|
</script>
|
|
<!-- 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 > 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 $2078. We can format the data as a string by
|
|
using <samp>Actions > Edit Operand</samp>,
|
|
setting the Character Encoding to <samp>Low or High ASCII</samp>,
|
|
and selecting <samp>null-terminated strings</samp>.</p>
|
|
</div>
|
|
</div>
|
|
|
|
<div class="grid-container">
|
|
<div class="grid-item-text">
|
|
<p>That's pretty straightforward, but this could quickly become tedious if
|
|
there were a lot of these. SourceGen allows you to define scripts to
|
|
automate common formatting tasks. This is covered in the "Extension
|
|
Scripts" tutorial.</p>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div> <!-- #main -->
|
|
|
|
<div id="prevnext">
|
|
<a href="#" class="btn-previous">« Previous</a>
|
|
<a href="#" class="btn-next">Next »</a>
|
|
</div>
|
|
|
|
<div id="footer">
|
|
<!-- START: /footer-incl.html -->
|
|
<script>$("#footer").load("/footer-incl.html");</script>
|
|
<!-- END: /footer-incl.html -->
|
|
</div>
|
|
|
|
</body>
|
|
</html>
|