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authorRobert P. J. Day <rpjday@crashcourse.ca>2014-07-03 08:00:07 -0400
committerSascha Hauer <s.hauer@pengutronix.de>2014-07-04 07:32:21 +0200
commit1df8c9efbfca820f2f75ef91495dd608dfbc3cfa (patch)
tree1bbe07fa1995c0fadbe49cf354d7c4bd303f8d1b /Documentation
parent4d62410b7492125ea4eb313e92ed8283b564cfe9 (diff)
downloadbarebox-1df8c9efbfca820f2f75ef91495dd608dfbc3cfa.tar.gz
barebox-1df8c9efbfca820f2f75ef91495dd608dfbc3cfa.tar.xz
Documentation: Various tweaks to user manual, device tree chapter.
Grammar, typoes, font, link fixes. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/user/devicetree.rst29
1 files changed, 15 insertions, 14 deletions
diff --git a/Documentation/user/devicetree.rst b/Documentation/user/devicetree.rst
index 856ff6a05b..17934d86e3 100644
--- a/Documentation/user/devicetree.rst
+++ b/Documentation/user/devicetree.rst
@@ -4,29 +4,29 @@ Devicetree support
==================
Flattened Device Tree (FDT) is a data structure for describing the hardware on
-a system. On an increasing number of boards both barebox and the Linux Kernel can
+a system. On an increasing number of boards, both barebox and the Linux kernel can
probe their devices directly from devicetrees. barebox needs the devicetree compiled
-into the binary. The Kernel usually does not have a devicetree compiled in, instead
-the Kernel expects to be passed a devicetree from the bootloader.
+into the binary. The kernel usually does not have a devicetree compiled in; instead,
+the kernel expects to be passed a devicetree from the bootloader.
From a bootloader's point of view, using devicetrees has the advantage that the
-same devicetree is used to probe both the Kernel and the Bootloader; this
+same devicetree can be used by both the bootloader and the kernel; this
drastically reduces porting effort since the devicetree has to be written only
-once (and with luck somebody has already written a devicetree for the Kernel).
-Probing barebox from devicetree is highly recommended for new projects.
+once (and with luck somebody has already written a devicetree for the kernel).
+Having barebox consult a devicetree is highly recommended for new projects.
.. _internal_devicetree:
The internal devicetree
-----------------------
-The devicetree barebox has been probed from plays a special role. It is referred to
-as the :ref:`internal_devicetree`. The barebox devicetree commands work on this
-devicetree. The devicetree source (DTS) files are kept in sync with the Kernel DTS
+The devicetree consulted by barebox plays a special role. It is referred to
+as the "internal devicetree." The barebox devicetree commands work on this
+devicetree. The devicetree source (DTS) files are kept in sync with the kernel DTS
files. As the FDT files are meant to be backward compatible, it should always be possible
-to start a Kernel with the barebox internal devicetree. However, since the barebox
+to start a kernel with the barebox internal devicetree. However, since the barebox
devicetree may not be complete or contain bugs it is always possible to start the
-Kernel with another devicetree than barebox has been started with.
+kernel with a devicetree different from the one used by barebox.
If a device has been probed from the devicetree then using the :ref:`command_devinfo`
command on it will show the corresponding devicetree node:
@@ -73,10 +73,11 @@ work on the internal devicetree. It is possible to add/remove nodes using the
It is important to know that these commands always work on the internal
devicetree. If you modify the internal devicetree to influence the behaviour of
-a Kernel booted later, make sure that you start the kernel with the internal
+a kernel booted later, make sure that you start the kernel with the internal
devicetree (i.e. don't pass a devicetree to the :ref:`command_bootm` command). If you
-wish to use another devicetree than the internal devicetree for starting the Kernel,
-you can exchange the internal devicetree during runtime:
+wish to use another devicetree than the internal devicetree for starting the kernel,
+you can exchange the internal devicetree during runtime using the
+:ref:`command_oftree` command:
.. code-block:: sh