Tell about MODULE_LICENSE and taint.

[cascardo/kernel/old_slides/.git] / 01.hello / 01.hello.xml

diff --git a/01.hello/01.hello.xml b/01.hello/01.hello.xml
index 954422f..b57177a 100644 (file)
--- a/01.hello/01.hello.xml
+++ b/01.hello/01.hello.xml
@@ -37,16 +37,36 @@ We have prepared sample code to build in the samples/ directory. Try them.
 <foil>
 <title>Init and Exit Functions</title>
 <para>
-We use <emphasis>module_init</emphasis> and <emphasis>module_exit</emphasis> to
-declare our init and exit functions.
+We use <emphasis>module\_init</emphasis> and <emphasis>module\_exit</emphasis>
+to declare our init and exit functions.
 </para>
 </foil>
 
 <foil>
 <title>Init and Exit Functions</title>
 <para>
-The <emphasis>__init</emphasis> and <emphasis>__exit</emphasis> marks allow the
-kernel to remove them when they are not needed, reducing memory consumption.
+The <emphasis>\_\_init</emphasis> and <emphasis>\_\_exit</emphasis> marks allow
+the kernel to remove them when they are not needed, reducing memory consumption.
+</para>
+</foil>
+
+<foil>
+<title>printk</title>
+<para>
+<emphasis>printk</emphasis> is very similar to printf. The messages are usually
+preceded by a string in the form &lt;n&gt;, where <emphasis>n</emphasis> is a
+priority. There are macros, like <emphasis>KERN\_ALERT</emphasis> and
+<emphasis>KERN\_DEBUG</emphasis> to use for that.
+</para>
+</foil>
+
+<foil>
+<title>License and taint</title>
+<para>
+<emphasis>MODULE\_LICENSE</emphasis> is highly recommended. A free software
+license should be used, otherwise the kernel is tainted. This indicates to
+developers that something has gone wrong, and some bug reports are ignored some
+times.
 </para>
 </foil>