testing grounds for loadable kernel modules (LKM)
Fedora
sudo dnf install git gcc make kernel-devel
Arch
sudo pacman -S git gcc make linux-headers
git clone https://github.com/holmanb/lkm.git
each directory contains a Makefile for running tests
each Makefile implements all/clean/test
to quickly test out modules in a VM, one can get up and running quickly with u-root + qemu + kvm
# initial setup
go get github.com/u-root/u-root
cd <project directory>
make all
u-root -files <kernel_module>.ko core boot
qemu-system-x86_64 -kernel /boot/vmlinuz-$(uname -r) -initrd /tmp/initramfs.linux_amd64.cpio
...
<in vm>
...
insmod <kernel_module>.ko
...
<interact with module>
...
rmmod <kernel_module>.ko
Source of Truth
https://github.com/torvalds/linux
Very Dated (2.6) But Valuable
http://tldp.org/LDP/lkmpg/2.6/html/index.html
A Short Character Device Blog Post
https://blog.sourcerer.io/writing-a-simple-linux-kernel-module-d9dc3762c234
Blog Post By Dr. Derek Molloy of Dublin City University, Ireland
www.derekmolloy.ie/writing-a-linux-kernel-module-part-1-introduction
Register A Device Class and Driver of a Dynamically Allocated Major Number From Kernel Space
www.derekmolloy.ie/writing-a-linux-kernel-module-part-2-a-character-device
Shows How To Add Ioctl To Char Device