tl;dr

  • Creating a simple example module
  • Creating Linux kernel configuration symbols
  • Configuring the Linux kernel build with menuconfig
  • Installing Linux kernel modules

Commands

make -C "$IIO_TREE" menuconfig # to enable a module in the menuconfig
cd "$IIO_TREE" && kw build --clean # clean artifacts from previous compilations
cd "$IIO_TREE" && kw build # build image and modules
modinfo <module_name> # see information about module of given name
lsmod # @VM list loaded modules
insmod <module_file.ko> # loads module at given location
rmmod <module_name> # unloads module of given name
modprobe <module_name> # loads module of given name and its dependencies 
modprobe -r <module_name> # unloads module of given name
depmod --quick # updates the module dependency list only if a module is added or removed
dmesg | tail # see last logs

Notes

Although the tutorial told us that the entries in the Kconfig were in alphabetical order, the order did not appear to be alphabetical.

When installing the Linux kernel modules with kw, I got an error saying that ${VM_MOUNT_POINT} wasn’t defined, to fix this I had to replace it with ${VM_DIR}/arm64_rootfs for the following command:

sudo guestunmount "$VM_MOUNT_POINT"

The rest of the tutorial was very clear. By the end, I had a working Linux kernel with the example modules.

Reference

Introduction to Linux kernel build configuration and modules