binman: Add documentation for bintools

Add this documention to explain how bintools are used and which ones are
available.

Signed-off-by: Simon Glass <sjg@chromium.org>

doc/develop/package/bintools.rst

@@ -0,0 +1 @@
+../../../tools/binman/bintools.rst

tools/binman/binman.rst

@@ -1027,6 +1027,77 @@ by increasing the -v/--verbosity from the default of 1:
 You can use BINMAN_VERBOSE=5 (for example) when building to select this.
 
 
+Bintools
+========
+
+`Bintool` is the name binman gives to a binary tool which it uses to create and
+manipulate binaries that binman cannot handle itself. Bintools are often
+necessary since Binman only supports a subset of the available file formats
+natively.
+
+Many SoC vendors invent ways to load code into their SoC using new file formats,
+sometimes changing the format with successive SoC generations. Sometimes the
+tool is available as Open Source. Sometimes it is a pre-compiled binary that
+must be downloaded from the vendor's website. Sometimes it is available in
+source form but difficult or slow to build.
+
+Even for images that use bintools, binman still assembles the image from its
+image description. It may handle parts of the image natively and part with
+various bintools.
+
+Binman relies on these tools so provides various features to manage them:
+
+- Determining whether the tool is currently installed
+- Downloading or building the tool
+- Determining the version of the tool that is installed
+- Deciding which tools are needed to build an image
+
+The Bintool class is an interface to the tool, a thin level of abstration, using
+Python functions to run the tool for each purpose (e.g. creating a new
+structure, adding a file to an existing structure) rather than just lists of
+string arguments.
+
+As with external blobs, bintools (which are like 'external' tools) can be
+missing. When building an image requires a bintool and it is not installed,
+binman detects this and reports the problem, but continues to build an image.
+This is useful in CI systems which want to check that everything is correct but
+don't have access to the bintools.
+
+To make this work, all calls to bintools (e.g. with Bintool.run_cmd()) must cope
+with the tool being missing, i.e. when None is returned, by:
+
+- Calling self.record_missing_bintool()
+- Setting up some fake contents so binman can continue
+
+Of course the image will not work, but binman reports which bintools are needed
+and also provide a way to fetch them.
+
+To see the available bintools, use::
+
+    binman tool --list
+
+To fetch tools which are missing, use::
+
+    binman tool --fetch missing
+
+You can also use `--fetch all` to fetch all tools or `--fetch <tool>` to fetch
+a particular tool. Some tools are built from source code, in which case you will
+need to have at least the `build-essential` and `git` packages installed.
+
+Bintool Documentation
+=====================
+
+To provide details on the various bintools supported by binman, bintools.rst is
+generated from the source code using:
+
+    binman bintool-docs >tools/binman/bintools.rst
+
+.. toctree::
+   :maxdepth: 2
+
+   bintools
+
+
 Technical details
 =================
 

tools/binman/bintools.rst

@@ -0,0 +1,115 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+Binman bintool Documentation
+============================
+
+This file describes the bintools (binary tools) supported by binman. Bintools
+are binman's name for external executables that it runs to generate or process
+binaries. It is fairly easy to create new bintools. Just add a new file to the
+'btool' directory. You can use existing bintools as examples.
+
+
+
+Bintool: cbfstool: Coreboot filesystem (CBFS) tool
+--------------------------------------------------
+
+This bintool supports creating new CBFS images and adding files to an
+existing image, i.e. the features needed by binman.
+
+It also supports fetching a binary cbfstool, since building it from source
+is fairly slow.
+
+Documentation about CBFS is at https://www.coreboot.org/CBFS
+
+
+
+Bintool: fiptool: Image generation for ARM Trusted Firmware
+-----------------------------------------------------------
+
+This bintool supports running `fiptool` with some basic parameters as
+neeed by binman.
+
+It also supports build fiptool from source.
+
+fiptool provides a way to package firmware in an ARM Trusted Firmware
+Firmware Image Package (ATF FIP) format. It is used with Trusted Firmware A,
+for example.
+
+See `TF-A FIP tool documentation`_ for more information.
+
+.. _`TF-A FIP tool documentation`:
+    https://trustedfirmware-a.readthedocs.io/en/latest/getting_started/tools-build.html?highlight=fiptool#building-and-using-the-fip-tool
+
+
+
+Bintool: futility: Handles the 'futility' tool
+----------------------------------------------
+
+futility (flash utility) is a tool for working with Chromium OS flash
+images. This Bintool implements just the features used by Binman, related to
+GBB creation and firmware signing.
+
+A binary version of the tool can be fetched.
+
+See `Chromium OS vboot documentation`_ for more information.
+
+.. _`Chromium OS vboot documentation`:
+    https://chromium.googlesource.com/chromiumos/platform/vboot/+/refs/heads/main/_vboot_reference/README
+
+
+
+Bintool: ifwitool: Handles the 'ifwitool' tool
+----------------------------------------------
+
+This bintool supports running `ifwitool` with some basic parameters as
+neeed by binman. It includes creating a file from a FIT as well as adding,
+replacing, deleting and extracting subparts.
+
+The tool is built as part of U-Boot, but a binary version can be fetched if
+required.
+
+ifwitool provides a way to package firmware in an Intel Firmware Image
+(IFWI) file on some Intel SoCs, e.g. Apolo Lake.
+
+
+
+Bintool: lz4: Compression/decompression using the LZ4 algorithm
+---------------------------------------------------------------
+
+This bintool supports running `lz4` to compress and decompress data, as
+used by binman.
+
+It is also possible to fetch the tool, which uses `apt` to install it.
+
+Documentation is available via::
+
+    man lz4
+
+
+
+Bintool: lzma_alone: Compression/decompression using the LZMA algorithm
+-----------------------------------------------------------------------
+
+This bintool supports running `lzma_alone` to compress and decompress data,
+as used by binman.
+
+It is also possible to fetch the tool, which uses `apt` to install it.
+
+Documentation is available via::
+
+    man lzma_alone
+
+
+
+Bintool: mkimage: Image generation for U-Boot
+---------------------------------------------
+
+This bintool supports running `mkimage` with some basic parameters as
+neeed by binman.
+
+Normally binman uses the mkimage built by U-Boot. But when run outside the
+U-Boot build system, binman can use the version installed in your system.
+Support is provided for fetching this on Debian-like systems, using apt.
+
+
+