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escape segment names ... Markdown! 😧

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Sami Samhuri 2014-06-23 21:43:45 -07:00
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public/posts/2010/01/basics-of-the-mach-o-file-format.md
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@ -34,7 +34,7 @@ Apple's Mach-O overview</a>, which illustrates this quite nicely.</p>
<p>A very basic Mach object file consists of a header followed by single
blob of machine code. That blob could be described by a single
section named __text, inside a single nameless segment. Here's a
section named \_\_text, inside a single nameless segment. Here's a
diagram showing the layout of such a file:</p>
<pre>
@ -77,7 +77,7 @@ is where in memory segments will ultimately end up.</p>
<p>Names are optional and can be arbitrary, but the convention is to
name segments with uppercase letters preceded by two underscores,
e.g. __DATA or __TEXT </p>
e.g. \_\_DATA or \_\_TEXT </p>
<p>The code exposes some more details about segment commands, but should
be easy enough to follow.</p>
@ -101,7 +101,7 @@ everything in memory the addresses inside our machine code will need
to be updated.</p>
<p>By convention segments are named with lowercase letters preceded by
two underscores, e.g. __bss or __text</p>
two underscores, e.g. \_\_bss or \_\_text</p>
<p>Finally, the Ruby code describing section structs:</p>
@ -130,9 +130,9 @@ beasts.</p>
<p>If you want to see the actual data for a section otool provides a
couple of ways to do this. The first is to use
<code>otool -d &lt;segment&gt; &lt;section&gt;</code> for an arbitrary
section. To see the contents of a well-known section, such as __text
in the __TEXT segment, use <code>otool -t /usr/bin/true</code>. You can
also disassemble the __text section with
section. To see the contents of a well-known section, such as \_\_text
in the \_\_TEXT segment, use <code>otool -t /usr/bin/true</code>. You can
also disassemble the \_\_text section with
<code>otool -tv /usr/bin/true</code>.</p>
<p>You'll get to know otool quite well if you work with Mach-O.</p>
@ -151,8 +151,8 @@ the next post we'll be there.</p>
<p><i>(You can almost do that with what we know now. If you
create a Mach file with a Mach header (ncmds=1), a single unnamed
segment (nsects=1), and then a section named __text with a segment
name of __TEXT, and some x86 machine code as the section data, you
segment (nsects=1), and then a section named \_\_text with a segment
name of \_\_TEXT, and some x86 machine code as the section data, you
would almost have a useful Mach object file.)</i></p>
<p>Until next time, happy hacking!</p>