public/post/architecture-of-linux-kernel/index.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94

<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="utf-8">
  
<title>Architecture of Linux Kernel | garhve&#x27;s gibberish</title>


  <link rel="shortcut icon" type="image/png" href="&#x2F;images&#x2F;favicon.png">
  <meta name="viewport" content="width=device-width,initial-scale=1">

  <link id="stylesheet" rel="stylesheet" type="text/css" href="/dark.css">

  <script type="text/javascript" src="/js/theme.js"></script>

</head>

<div class="header">
  <div class="site_title">
    <p><a href="/"><img src="https:&#x2F;&#x2F;blog.garhve.com&#x2F;images&#x2F;logo.ico" alt="garhve&#x27;s gibberish"
          width="70" height=auto></a></p>
    <p><a href="/">&nbsp;garhve&#x27;s gibberish</a></p>
  </div>
  <div class="menu">
      <!--    <a href="/tags">tags</a>
          &nbsp;--><a href="/categories">categories</a>
  </div>
</div>

<body onload="getTheme()">
  <section class="section">
    <div class="container">
      
<p>
  <div class="title_postpage">Architecture of Linux Kernel</div>
</p>
<p>
  <div class="date_postpage">2022-09-03</div>
  <div class="taxonomies_postpage">
  
      
      <a href="https://blog.garhve.com/categories/cs/">/cs</a>
      
  
      &emsp;<a href="https://blog.garhve.com/tags/linux/">#linux</a>
      
  
  </div>
</p>

<p>
  <h2 id="description">Description</h2>
<p>Modern microcontrollers nowadays support at least two privilege levels. Intel/AMD x86-64 family supports 4 levels, whilst ARM (32bit) microcontrollers support up to 7 levels (6 privileged, 1 non-privileged).</p>
<p>Modern operating systems support at least 2 levels:</p>
<ul>
<li><strong>User space</strong>: For applications to run in unprivileged user mode</li>
<li><strong>Kernel space</strong>: For the kernel (and all its components) to run in privileged mode – kernel mode</li>
</ul>
<p>Address of these 2 spaces are separate.</p>
<p>Applications in user mode will auto-linked to glibc(the GNU standard C library). Libraries only available in user mode, kernel mode doesn't have this conception. An application only can through <strong>System call</strong> to access kernel. On the other hand, system calls are the only legal entry point into the kernel space.</p>
<blockquote>
<p>Libraries APIs: man section 3
System calls APIs: man section 2</p>
</blockquote>
<p>to be continue...</p>

</p>


<script>
  MathJax = {
    tex: {
      inlineMath: [['$', '$'], ['\\(', '\\)']]
    }
  };
</script>
<script type="text/javascript" async
  src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js">
</script>


    </div>
  </section>
</body>

<div class="footer">
  &emsp;&copy; garhve
</div>

</html>