{"id":7176,"date":"2022-02-07T04:08:22","date_gmt":"2022-02-07T04:08:22","guid":{"rendered":"http:\/\/fastbitlab.com\/?p=7176"},"modified":"2023-09-12T14:58:13","modified_gmt":"2023-09-12T09:28:13","slug":"linux-device-driver-programming-lecture-20-writing-hello-world-lkm","status":"publish","type":"post","link":"https:\/\/fastbitlab.com\/blog\/linux-device-driver-programming-lecture-20-writing-hello-world-lkm\/","title":{"rendered":"Linux Device Driver Programming Lecture 20- Writing Hello World LKM"},"content":{"rendered":"
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Writing Hello World LKM<\/b><\/span><\/h1>\n
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In this article, let’s implement the Hello World kernel module and test it, then will explore how to build it<\/a><\/span>.<\/span><\/p>\n

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Setting Up the Project:<\/strong><\/span><\/p>\n

Create a directory for your Hello World LKM, e.g., “001hello_world.”<\/span><\/p>\n

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Figure 1. Create 001hello_world directory<\/span><\/figcaption><\/figure>\n

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Creating the Main C File:<\/strong><\/span><\/span><\/p>\n

Inside the directory, create a file named “main.c.”<\/span><\/p>\n

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Figure 2. Create main.c file<\/span><\/figcaption><\/figure>\n

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Editing the Main C File:<\/strong><\/span><\/span><\/p>\n

Let’s open main.c, you can use your favorite text editors. Let\u2019s use vim, or you can even use gedit or your favorite text editors, as shown in Figure 3.<\/span><\/p>\n

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Figure 3. Open main.c using vim text editor<\/span><\/figcaption><\/figure>\n

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Including Kernel Headers:<\/strong><\/span><\/span><\/p>\n

First, we have to include the header file. We have to include the kernel header file with respect to the Linux folder that is Linux module.h. If you are not sure about that, let me save and exit this.<\/span><\/p>\n