uboot: (firmwareOdroidC2/C4) don't invoke patch tool, use patches = [] instead

https://github.com/NixOS/nixpkgs/blob/master/pkgs/stdenv/generic/setup.sh#L948
this can do it nicely.

Signed-off-by: Anton Arapov <anton@deadbeef.mx>

nixos/doc/manual/development/writing-documentation.chapter.md

@@ -0,0 +1,93 @@
+# Writing NixOS Documentation {#sec-writing-documentation}
+
+As NixOS grows, so too does the need for a catalogue and explanation of
+its extensive functionality. Collecting pertinent information from
+disparate sources and presenting it in an accessible style would be a
+worthy contribution to the project.
+
+## Building the Manual {#sec-writing-docs-building-the-manual}
+
+The DocBook sources of the [](#book-nixos-manual) are in the
+[`nixos/doc/manual`](https://github.com/NixOS/nixpkgs/tree/master/nixos/doc/manual)
+subdirectory of the Nixpkgs repository.
+
+You can quickly validate your edits with `make`:
+
+```ShellSession
+$ cd /path/to/nixpkgs/nixos/doc/manual
+$ nix-shell
+nix-shell$ make
+```
+
+Once you are done making modifications to the manual, it\'s important to
+build it before committing. You can do that as follows:
+
+```ShellSession
+nix-build nixos/release.nix -A manual.x86_64-linux
+```
+
+When this command successfully finishes, it will tell you where the
+manual got generated. The HTML will be accessible through the `result`
+symlink at `./result/share/doc/nixos/index.html`.
+
+## Editing DocBook XML {#sec-writing-docs-editing-docbook-xml}
+
+For general information on how to write in DocBook, see [DocBook 5: The
+Definitive Guide](http://www.docbook.org/tdg5/en/html/docbook.html).
+
+Emacs nXML Mode is very helpful for editing DocBook XML because it
+validates the document as you write, and precisely locates errors. To
+use it, see [](#sec-emacs-docbook-xml).
+
+[Pandoc](http://pandoc.org) can generate DocBook XML from a multitude of
+formats, which makes a good starting point. Here is an example of Pandoc
+invocation to convert GitHub-Flavoured MarkDown to DocBook 5 XML:
+
+```ShellSession
+pandoc -f markdown_github -t docbook5 docs.md -o my-section.md
+```
+
+Pandoc can also quickly convert a single `section.xml` to HTML, which is
+helpful when drafting.
+
+Sometimes writing valid DocBook is simply too difficult. In this case,
+submit your documentation updates in a [GitHub
+Issue](https://github.com/NixOS/nixpkgs/issues/new) and someone will
+handle the conversion to XML for you.
+
+## Creating a Topic {#sec-writing-docs-creating-a-topic}
+
+You can use an existing topic as a basis for the new topic or create a
+topic from scratch.
+
+Keep the following guidelines in mind when you create and add a topic:
+
+-   The NixOS [`book`](http://www.docbook.org/tdg5/en/html/book.html)
+    element is in `nixos/doc/manual/manual.xml`. It includes several
+    [`parts`](http://www.docbook.org/tdg5/en/html/book.html) which are in
+    subdirectories.
+
+-   Store the topic file in the same directory as the `part` to which it
+    belongs. If your topic is about configuring a NixOS module, then the
+    XML file can be stored alongside the module definition `nix` file.
+
+-   If you include multiple words in the file name, separate the words
+    with a dash. For example: `ipv6-config.xml`.
+
+-   Make sure that the `xml:id` value is unique. You can use abbreviations
+    if the ID is too long. For example: `nixos-config`.
+
+-   Determine whether your topic is a chapter or a section. If you are
+    unsure, open an existing topic file and check whether the main
+    element is chapter or section.
+
+## Adding a Topic to the Book {#sec-writing-docs-adding-a-topic}
+
+Open the parent XML file and add an `xi:include` element to the list of
+chapters with the file name of the topic that you created. If you
+created a `section`, you add the file to the `chapter` file. If you created
+a `chapter`, you add the file to the `part` file.
+
+If the topic is about configuring a NixOS module, it can be
+automatically included in the manual by using the `meta.doc` attribute.
+See [](#sec-meta-attributes) for an explanation.