Linux 802.11n CSI Tool for newer Linux kernels

Intro

The purpose of this repository is to provide support for building the CSI-enabled Wi-Fi drivers for Intel Wireless Link 5300 adapters on Linux distributions with newer kernel versions. At this point this code has been tested on Ubuntu 16.04 and Ubuntu 18.04 with kernel version 4.15. More tests are expected soon.

The code presented here comprises of a modified version of the Linux kernel. The modifications were made by examining the code provided by dhalperi/linux-80211n-csitool and adapting them to more recent Linux kernel versions - iwlwifi module. The building and installation instructions were taken from the original Linux 802.11n CSI Tool website and adapted accordingly.

Installation Instructions

Prerequisites

Kernel version

Before proceeding further, you need to check the version of your kernel. It should be 4.15, otherwise the commands below won't work. The following command will print that information:

$ uname -r

Required packages

$ sudo apt install build-essential linux-headers-$(uname -r) git-core

Compilers with retpoline support (Ubuntu 16.04)

Newer kernels require compilers with retpoline supports. GCC and G++ version 7.3 and above support that feature. The example below shows how to install GCC/G++ version 8:

$ sudo add-apt-repository ppa:ubuntu-toolchain-r/test
$ sudo apt update
$ sudo apt install gcc-8 g++-8

You need to ensure that the make command uses the right version of the compilers. You can use either of these two ways do it

Redirect the system-wide links to the compiler executables

Check where the current links point to. The command

$ ls -l /usr/bin/gcc /usr/bin/g++

should generate an output similar to

lrwxrwxrwx 1 root 5 Mar 27  2018 /usr/bin/g++ -> g++-5
lrwxrwxrwx 1 root 5 Mar 27  2018 /usr/bin/gcc -> gcc-5

The current links are pointing to version 5. So they need to be redirected to version 8. To do that, remove the current links

$ sudo rm /usr/bin/gcc
$ sudo rm /usr/bin/g++

and create the new ones

$ sudo ln -s /usr/bin/gcc-8 /usr/bin/gcc
$ sudo ln -s /usr/bin/g++-8 /usr/bin/g++

Build and Install the Modified Wireless Driver

Clone the modified Linux kernel code

$ git clone https://github.com/spanev/linux-80211n-csitool.git
$ cd linux-80211n-csitool

Checkout the correct release version

$ CSITOOL_KERNEL_TAG=csitool-$(uname -r | cut -d . -f 1-2)
$ git checkout ${CSITOOL_KERNEL_TAG}

Build the modified driver for the existing kernel

$ make -j `nproc` -C /lib/modules/$(uname -r)/build M=$(pwd)/drivers/net/wireless/intel/iwlwifi modules

$ sudo make -C /lib/modules/$(uname -r)/build M=$(pwd)/drivers/net/wireless/intel/iwlwifi \
> INSTALL_MOD_DIR=updates modules_install

Remark: If during the execution of the command above you get error messages similar to

- SSL error:02001002:system library:fopen:No such file or directory: bss_file.c:175
- SSL error:2006D080:BIO routines:BIO_new_file:no such file: bss_file.c:178
sign-file: certs/signing_key.pem: No such file or directory

do not worry. The operating system complains, because the driver doesn't have a SSL signature. That won't interfere with the driver installation. Therefore, simply ignore the messages and continue with the installation process.

$ sudo depmod
$ cd ..

Install the Modified Firmware

Obtain the CSI Tool supplementary material:

$ git clone https://github.com/dhalperi/linux-80211n-csitool-supplementary.git

Relocate any existing firmware for Intel Wi-Fi Link 5000 Series adapters:

$ for file in /lib/firmware/iwlwifi-5000-*.ucode; do sudo mv $file $file.orig; done

Install the modified firmware:

$ sudo cp linux-80211n-csitool-supplementary/firmware/iwlwifi-5000-2.ucode.sigcomm2010 /lib/firmware/
$ sudo ln -s iwlwifi-5000-2.ucode.sigcomm2010 /lib/firmware/iwlwifi-5000-2.ucode

Enable logging and testing the driver

In order to conduct tests with the newly installed driver, please refer to the original CSI Tool website's installation instructions, Section 4 and 5.