Linux Kernel 4.2 was released yesterday, at noon. Linus Torvalds wrote on lkml.org:

So judging by how little happened this week, it wouldn’t have been a mistake to release 4.2 last week after all, but hey, there’s certainly a few fixes here, and it’s not like delaying 4.2 for a week should have caused any problems either.

So here it is, and the merge window for 4.3 is now open. I already have a few pending early pull requests, but as usual I’ll start processing them tomorrow and give the release some time to actually sit.

The shortlog from rc8 is tiny, and appended. The patch is pretty tiny too…

What’s New in Kernel 4.2:

• rewrites of Intel Assembly x86 code
• support for new ARM boards and SoCs
• F2FS per-file encryption
• The AMDGPU kernel DRM driver
• VCE1 video encode support for the Radeon DRM driver
• Initial support for Intel Broxton Atom SoCs
• Support for ARCv2 and HS38 CPU cores.
• added queue spinlocks support
• many other improvements and updated drivers.

How to Install Kernel 4.2 in Ubuntu:

The binary packages of this kernel release are available for download at link below:

Download Kernel 4.2 (.DEB)

NOTE: The kernel binaries are marked as UNSTABLE (see the link url). You may not do this in a production machine, or you have to know what you’re going to do and know about how to restore if something goes wrong (or see the link at bottom).

First check out your OS type, 32-bit (i386) or 64-bit (amd64), then download and install the packages below in turn:

1. linux-headers-4.2.0-xxx_all.deb
2. linux-headers-4.2.0-xxx-generic_xxx_i386/amd64.deb
3. linux-image-4.2.0-xxx-generic_xxx_i386/amd64.deb

After installing the kernel, you may run sudo update-grub command in terminal (Ctrl+Alt+T) to refresh grub boot-loader.

If you need a low latency system (e.g. for recording audio) then download & install below packages instead:

1. linux-headers-4.2.0_xxx_all.deb
2. linux-headers-4.2.0-xxx-lowlatency_xxx_i386/amd64.deb
3. linux-image-4.2.0-xxx-lowlatency_xxx_i386/amd64.deb

For Ubuntu Server without a graphical UI, you may run below commands one by one to grab packages via wget and install them via dpkg:

For 64-bit system run:

cd /tmp/

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-headers-4.2.0-040200_4.2.0-040200.201508301530_all.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-headers-4.2.0-040200-generic_4.2.0-040200.201508301530_amd64.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-image-4.2.0-040200-generic_4.2.0-040200.201508301530_amd64.deb

sudo dpkg -i linux-headers-4.2.0-*.deb linux-image-4.2.0-*.deb

For 32-bit system, run:

cd /tmp/

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-headers-4.2.0-040200_4.2.0-040200.201508301530_all.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-headers-4.2.0-040200-generic_4.2.0-040200.201508301530_i386.deb

wget http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.2-unstable/linux-image-4.2.0-040200-generic_4.2.0-040200.201508301530_i386.deb

sudo dpkg -i linux-headers-4.2.0-*.deb linux-image-4.2.0-*.deb

Finally restart your computer to take effect.

To revert back, remove old kernels, see install kernel simply via a script.

Want to install the latest Linux Kernel? A simple script can always do the job and make things easier in Ubuntu.

Michael Murphy has created a script makes installing the latest RC, stable, or lowlatency Kernel easier in Ubuntu. The script asks some questions and automatically downloads and installs the latest Kernel packages from Ubuntu kernel mainline page.

Install / Upgrade Linux Kernel via the Script:

1. Download the script from the right sidebar of the github page (click the “Download Zip” button).

2. Decompress the Zip archive by right-clicking on it in your user Downloads folder and select “Extract Here”.

3. Navigate to the result folder in terminal by right-clicking on that folder and select “Open in Terminal”:

It opens a terminal window and automatically navigates into the result folder. If you DON’T find the “Open in Terminal” option, search for and install nautilus-open-terminal in Ubuntu Software Center and then log out and back in (or run nautilus -q command in terminal instead to apply changes).

4. When you’re in terminal, give the script executable permission for once.

chmod +x *

FINALLY run the script every time you want to install / upgrade Linux Kernel in Ubuntu:

./*

I use * instead of the SCRIPT NAME in both commands since it’s the only file in that folder.

If the script runs successfully, restart your computer when done.

Revert back and Uninstall the new Kernel:

To revert back and remove the new kernel for any reason, restart your computer and select boot with the old kernel entry under Advanced Options menu when you’re at Grub boot-loader.

When it boots up, see below section.

How to Remove the old (or new) Kernels:

1. Install Synaptic Package Manager from Ubuntu Software Center.

2. Launch Synaptic Package Manager and do:

• click the Reload button in case you want to remove the new kernel.
• select Status -> Installed on the left pane to make search list clear.
• search linux-image- using Quick filter box.
• select a kernel image “linux-image-x.xx.xx-generic” and mark for (complete) removal
• finally apply changes

Repeat until you removed all unwanted kernels. DON’T carelessly remove the current running kernel, check it out via uname -r (see below pic.) command.

For Ubuntu Server, you may run below commands one by one:

uname -r

dpkg -l | grep linux-image-

sudo apt-get autoremove KERNEL_IMAGE_NAME