···

       
19
       
19
       
 
       


     

       
20
       
20
       
 
       
<para>The default Linux kernel configuration should be fine for most users. You can see the configuration of your current kernel with the following command:

     

       
21
       
21
       
 
       
<programlisting>

     

       
22
       
22
       
-
       
cat /proc/config.gz | gunzip

     

       
22
       
22
       
+
       
zcat /proc/config.gz

     

       
23
       
23
       
 
       
</programlisting>

     

       
24
       
24
       
 
       
If you want to change the kernel configuration, you can use the

     

       
25
       
25
       
 
       
<option>packageOverrides</option> feature (see <xref

     

···

       
7
       
7
       
 
       
<title>Option Declarations</title>

     

       
8
       
8
       
 
       


     

       
9
       
9
       
 
       
<para>An option declaration specifies the name, type and description

     

       
10
       
10
       
-
       
of a NixOS configuration option.  It is illegal to define an option

     

       
11
       
11
       
-
       
that hasn’t been declared in any module.  A option declaration

     

       
10
       
10
       
+
       
of a NixOS configuration option.  It is invalid to define an option

     

       
11
       
11
       
+
       
that hasn’t been declared in any module.  An option declaration

     

       
12
       
12
       
 
       
generally looks like this:

     

       
13
       
13
       
 
       


     

       
14
       
14
       
 
       
<programlisting>

     
···

       
42
       
42
       
 
       
    <listitem>

     

       
43
       
43
       
 
       
      <para>The default value used if no value is defined by any

     

       
44
       
44
       
 
       
      module.  A default is not required; in that case, if the option

     

       
45
       
45
       
-
       
      value is ever used, an error will be thrown.</para>

     

       
45
       
45
       
+
       
      value is never used, an error will be thrown.</para>

     

       
46
       
46
       
 
       
    </listitem>

     

       
47
       
47
       
 
       
  </varlistentry>

     

       
48
       
48