5 Minute "Hello, World!" Linux Kernel Driver

Updated: Jan 5, 2019



This post shows you how to build and test a "Hello, World " Linux kernel driver in 5 min.


Before you Start


Read and follow the ARM instructions listed in 15 Minute Setup to Find, Change, Recompile and Test an ARM or x86 Linux Kernel Change in 12 Seconds at [link]


Steps


Set Up the Makefiles


1. Type cd ~/tla/linux-4.10.6

2. Type mkdir -p drivers/demo

3. Type vi drivers/Makefile

4. Add obj-y += demo/

5. Save the file with :w and quit with :q

6. Type vi drivers/demo/Makefile

7. Add obj-y += demo.o

8. Save the file with :w and quit with :q


Write the Driver


1. Type cd ~/tla/linux-4.10.6

2. Type vi drivers/demo/demo.c

3. Enter:

4. Save the file with :w and quit with :q


Compile and Run It


1. Type cd ~/tla/linux-4.10.6

2. Type source ~/envset.sh

3. Type make


You should see:

4. Run it by typing:

You should see (look for >>>>>>>>>> Hello, World! <<<<<<<<<<):



5. Type Control-a x to quit QEMU



References

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