arm: docs: Move Arm documentation to Documentation/arch/

Architecture-specific documentation is being moved into Documentation/arch/
as a way of cleaning up the top-level documentation directory and making
the docs hierarchy more closely match the source hierarchy.  Move
Documentation/arm into arch/ (along with the Chinese equvalent
translations).

Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Jernej Skrabec <jernej.skrabec@gmail.com>
Cc: Samuel Holland <samuel@sholland.org>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Cc: Alim Akhtar <alim.akhtar@samsung.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arch@vger.kernel.org
Acked-by: Alexandre TORGUE <alexandre.torgue@foss.st.com>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 0 insertions, 69 deletions

diff --git a/Documentation/arm/google/chromebook-boot-flow.rst b/Documentation/arm/google/chromebook-boot-flow.rst
deleted file mode 100644
index 36da77684bba..000000000000
--- a/Documentation/arm/google/chromebook-boot-flow.rst
+++ /dev/null
@@ -1,69 +0,0 @@
-.. SPDX-License-Identifier: GPL-2.0
-
-======================================
-Chromebook Boot Flow
-======================================
-
-Most recent Chromebooks that use device tree are using the opensource
-depthcharge_ bootloader. Depthcharge_ expects the OS to be packaged as a `FIT
-Image`_ which contains an OS image as well as a collection of device trees. It
-is up to depthcharge_ to pick the right device tree from the `FIT Image`_ and
-provide it to the OS.
-
-The scheme that depthcharge_ uses to pick the device tree takes into account
-three variables:
-
-- Board name, specified at depthcharge_ compile time. This is $(BOARD) below.
-- Board revision number, determined at runtime (perhaps by reading GPIO
-  strappings, perhaps via some other method). This is $(REV) below.
-- SKU number, read from GPIO strappings at boot time. This is $(SKU) below.
-
-For recent Chromebooks, depthcharge_ creates a match list that looks like this:
-
-- google,$(BOARD)-rev$(REV)-sku$(SKU)
-- google,$(BOARD)-rev$(REV)
-- google,$(BOARD)-sku$(SKU)
-- google,$(BOARD)
-
-Note that some older Chromebooks use a slightly different list that may
-not include SKU matching or may prioritize SKU/rev differently.
-
-Note that for some boards there may be extra board-specific logic to inject
-extra compatibles into the list, but this is uncommon.
-
-Depthcharge_ will look through all device trees in the `FIT Image`_ trying to
-find one that matches the most specific compatible. It will then look
-through all device trees in the `FIT Image`_ trying to find the one that
-matches the *second most* specific compatible, etc.
-
-When searching for a device tree, depthcharge_ doesn't care where the
-compatible string falls within a device tree's root compatible string array.
-As an example, if we're on board "lazor", rev 4, SKU 0 and we have two device
-trees:
-
-- "google,lazor-rev5-sku0", "google,lazor-rev4-sku0", "qcom,sc7180"
-- "google,lazor", "qcom,sc7180"
-
-Then depthcharge_ will pick the first device tree even though
-"google,lazor-rev4-sku0" was the second compatible listed in that device tree.
-This is because it is a more specific compatible than "google,lazor".
-
-It should be noted that depthcharge_ does not have any smarts to try to
-match board or SKU revisions that are "close by". That is to say that
-if depthcharge_ knows it's on "rev4" of a board but there is no "rev4"
-device tree then depthcharge_ *won't* look for a "rev3" device tree.
-
-In general when any significant changes are made to a board the board
-revision number is increased even if none of those changes need to
-be reflected in the device tree. Thus it's fairly common to see device
-trees with multiple revisions.
-
-It should be noted that, taking into account the above system that
-depthcharge_ has, the most flexibility is achieved if the device tree
-supporting the newest revision(s) of a board omits the "-rev{REV}"
-compatible strings. When this is done then if you get a new board
-revision and try to run old software on it then we'll at pick the
-newest device tree we know about.
-
-.. _depthcharge: https://source.chromium.org/chromiumos/chromiumos/codesearch/+/main:src/platform/depthcharge/
-.. _`FIT Image`: https://doc.coreboot.org/lib/payloads/fit.html