diff --git a/doc/process/KernelTree.rst b/doc/process/KernelTree.rst
new file mode 100644
index 0000000..87ec71c
--- /dev/null
+++ b/doc/process/KernelTree.rst
@@ -0,0 +1,55 @@
+op-build Linux Kernel
+=====================
+
+The skiroot/Petitboot kernel is currently based on the 4.17 series.
+
+Submitting a patch
+------------------
+
+If you require a patch added to the firmware, follow these steps:
+
+1. Submit your patch upstream. It doesn’t need to be upstream, but it
+   should be on it’s way
+2. Send a pull request or a ``git format-patch`` formatted patch series
+   to openpower-firmware@lists.ozlabs.org, and cc joel@jms.id.au. Be
+   sure to use ``--suppress-cc=sob`` when generating the patches so we
+   don’t spam the community. The current tree is based on 4.15-stable.
+
+Bug fixes
+---------
+
+Whenever a stable release is tagged in
+https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/,
+we will rebase our patches on top of that and create a new release.
+
+If you are submitting patches upstream that you want to be included,
+then ensure you cc stable as per the
+`rules <https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/plain/Documentation/stable_kernel_rules.txt>`__.
+
+Versioning
+----------
+
+Versions are the upstream version number, followed by ``-openpowerN``,
+where N is the revision that counts up from 1 for the given upstream
+version number. These versions will be present as tags in the git
+repository hosted at https://github.com/open-power/linux.
+
+Tree and patches
+----------------
+
+The kernel tree hosted at https://github.com/open-power/linux contains
+the current release plus a set of patches that we carry. Ideally there
+would be no patches carried, as everything should be upstream.
+
+We take the commits in this tree between the upstream tag and the
+openpower tag and generate a series of patches that are imported into
+the op-build Buildroot overlay, and placed in
+`op-build/openpower/linux <https://github.com/open-power/op-build/tree/master/openpower/linux>`_.
+op-build then fetches the upstream tarball and applies these patches.
+This way we don’t have to clone an entire tree when doing an op-build
+build.
+
+Patches in the tree
+-------------------
+
+-  xhci: Reset controller on xhci shutdown
diff --git a/doc/process/index.rst b/doc/process/index.rst
index 024518b..a8443ba 100644
--- a/doc/process/index.rst
+++ b/doc/process/index.rst
@@ -4,3 +4,4 @@
 .. toctree::
 
    CONTRIBUTING.md
+   KernelTree.rst