DKMS and Building Kernel Modules on Ubuntu

This article explains DKMS usage and manual kernel module build steps with concrete commands. DKMS automates rebuilding modules when the kernel is updated.

1 Install DKMS and kernel headers

sudo apt update
sudo apt install -y dkms build-essential linux-headers-$(uname -r)

Confirm headers match uname -r.

2 Simple manual build (for testing)

Create a minimal module in ~/projects/hellomodule/:

hellomodule.c:

#include <linux/module.h>
#include <linux/kernel.h>
static int __init hello_init(void){ printk(KERN_INFO "hello loaded\n"); return 0; }
static void __exit hello_exit(void){ printk(KERN_INFO "hello unloaded\n"); }
module_init(hello_init);
module_exit(hello_exit);
MODULE_LICENSE("GPL");

Makefile:

obj-m += hellomodule.o
all:
  make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
clean:
  make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean

Build and load:

make
sudo insmod hellomodule.ko
dmesg | tail
sudo rmmod hellomodule

3 DKMS workflow (packaging a module)

Create /usr/src/yourmod-1.0/ with source and a dkms.conf describing the module. Minimal dkms.conf:

PACKAGE_NAME="yourmod"
PACKAGE_VERSION="1.0"
BUILT_MODULE_NAME[0]="yourmod"
DEST_MODULE_LOCATION[0]="/kernel/drivers/misc"
AUTOINSTALL="yes"

sudo dkms add -m yourmod -v 1.0
sudo dkms build -m yourmod -v 1.0
sudo dkms install -m yourmod -v 1.0

DKMS stores builds under /var/lib/dkms/yourmod/1.0/ and will rebuild automatically on kernel updates.

To remove:

sudo dkms remove -m yourmod -v 1.0 --all

4 Troubleshooting DKMS builds

View build logs: /var/lib/dkms/<module>/<version>/build/make.log.
Ensure matching linux-headers-$(uname -r) are installed.
If a DKMS build fails after a kernel update, manually run dkms build to see errors and fix missing symbols or API changes.
Use dkms status to list installed modules and their build state.