From 1df8c9efbfca820f2f75ef91495dd608dfbc3cfa Mon Sep 17 00:00:00 2001 From: "Robert P. J. Day" Date: Thu, 3 Jul 2014 08:00:07 -0400 Subject: [PATCH] Documentation: Various tweaks to user manual, device tree chapter. Grammar, typoes, font, link fixes. Signed-off-by: Robert P. J. Day Signed-off-by: Sascha Hauer --- Documentation/user/devicetree.rst | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) diff --git a/Documentation/user/devicetree.rst b/Documentation/user/devicetree.rst index 856ff6a05..17934d86e 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