Load linux kernel module at boot

Question

I have written a kernel module for a study research project that is a driver for seven segment displays connected to a Raspberry Pi (I am pretty new to kernel development). I would like to permanently install the module and load it at boot time when it is compiled, so I added the install target to my Makefile which allows the user to directly compile and install it.

I found out that all kernel modules are located somewhere inside /lib/modules/<kernel version>/kernel, so I thought I just had to copy the compiled module into a subdirectory and list the module in the modules.order and modules.dep files. However, this approach did not work and since I could not find any resources to that topic, I am a little desperate.

This is what my Makefile currently looks like:

# All source files are inside the src directory
obj-m := src/sevenseg.o

all:
    make -C /lib/modules/$(shell uname -r)/build EXTRA_CFLAGS=-I$(PWD)/src M=$(PWD) modules
    mv src/sevenseg.ko .

install:
    make -C /lib/modules/$(shell uname -r)/build EXTRA_CFLAGS=-I$(PWD)/src M=$(PWD) modules
    mkdir -p /lib/modules/$(shell uname -r)/kernel/drivers/sevenseg
    cp src/sevenseg.ko /lib/modules/$(shell uname -r)/kernel/drivers/sevenseg
    echo "kernel/drivers/sevenseg/sevenseg.ko:" >> /lib/modules/$(shell uname -r)/modules.dep
    echo "kernel/drivers/sevenseg/sevenseg.ko" >> /lib/modules/$(shell uname -r)/modules.order
    insmod src/sevenseg.ko
    make clean

clean:
    rm -rf src

How do I tell the kernel that it should load the module sevenseg.ko at boot time?

rubicks rubicks · Accepted Answer · 2017-12-30T17:37:21

tldr;

# echo 'my-module-name' >> /etc/modules

Longer explanation:

Consult the documentation on insmod, modprobe, and modprobe.conf.

Here's a decent tutorial: https://www.cyberciti.biz/faq/linux-how-to-load-a-kernel-module-automatically-at-boot-time/

Load linux kernel module at boot

1 Answers