binman: Introduce binman, a tool for building binary images

This adds the basic code for binman, including command parsing, processing
of entries and generation of images.

So far no entry types are supported. These will be added in future commits
as examples of how to add new types.

See the README for documentation.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

9 files changed, 1255 insertions, 0 deletions

diff --git a/tools/binman/.gitignore b/tools/binman/.gitignore
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--- /dev/null
+++ b/tools/binman/.gitignore
@@ -0,0 +1 @@
+*.pyc
diff --git a/tools/binman/README b/tools/binman/README
new file mode 100644
index 0000000..c73fb3c
--- /dev/null
+++ b/tools/binman/README
@@ -0,0 +1,491 @@
+# Copyright (c) 2016 Google, Inc
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+Introduction
+------------
+
+Firmware often consists of several components which must be packaged together.
+For example, we may have SPL, U-Boot, a device tree and an environment area
+grouped together and placed in MMC flash. When the system starts, it must be
+able to find these pieces.
+
+So far U-Boot has not provided a way to handle creating such images in a
+general way. Each SoC does what it needs to build an image, often packing or
+concatenating images in the U-Boot build system.
+
+Binman aims to provide a mechanism for building images, from simple
+SPL + U-Boot combinations, to more complex arrangements with many parts.
+
+
+What it does
+------------
+
+Binman reads your board's device tree and finds a node which describes the
+required image layout. It uses this to work out what to place where. The
+output file normally contains the device tree, so it is in principle possible
+to read an image and extract its constituent parts.
+
+
+Features
+--------
+
+So far binman is pretty simple. It supports binary blobs, such as 'u-boot',
+'spl' and 'fdt'. It supports empty entries (such as setting to 0xff). It can
+place entries at a fixed location in the image, or fit them together with
+suitable padding and alignment. It provides a way to process binaries before
+they are included, by adding a Python plug-in. The device tree is available
+to U-Boot at run-time so that the images can be interpreted.
+
+Binman does not yet update the device tree with the final location of
+everything when it is done. A simple C structure could be generated for
+constrained environments like SPL (using dtoc) but this is also not
+implemented.
+
+Binman can also support incorporating filesystems in the image if required.
+For example x86 platforms may use CBFS in some cases.
+
+Binman is intended for use with U-Boot but is designed to be general enough
+to be useful in other image-packaging situations.
+
+
+Motivation
+----------
+
+Packaging of firmware is quite a different task from building the various
+parts. In many cases the various binaries which go into the image come from
+separate build systems. For example, ARM Trusted Firmware is used on ARMv8
+devices but is not built in the U-Boot tree. If a Linux kernel is included
+in the firmware image, it is built elsewhere.
+
+It is of course possible to add more and more build rules to the U-Boot
+build system to cover these cases. It can shell out to other Makefiles and
+build scripts. But it seems better to create a clear divide between building
+software and packaging it.
+
+At present this is handled by manual instructions, different for each board,
+on how to create images that will boot. By turning these instructions into a
+standard format, we can support making valid images for any board without
+manual effort, lots of READMEs, etc.
+
+Benefits:
+- Each binary can have its own build system and tool chain without creating
+any dependencies between them
+- Avoids the need for a single-shot build: individual parts can be updated
+and brought in as needed
+- Provides for a standard image description available in the build and at
+run-time
+- SoC-specific image-signing tools can be accomodated
+- Avoids cluttering the U-Boot build system with image-building code
+- The image description is automatically available at run-time in U-Boot,
+SPL. It can be made available to other software also
+- The image description is easily readable (it's a text file in device-tree
+format) and permits flexible packing of binaries
+
+
+Terminology
+-----------
+
+Binman uses the following terms:
+
+- image - an output file containing a firmware image
+- binary - an input binary that goes into the image
+
+
+Relationship to FIT
+-------------------
+
+FIT is U-Boot's official image format. It supports multiple binaries with
+load / execution addresses, compression. It also supports verification
+through hashing and RSA signatures.
+
+FIT was originally designed to support booting a Linux kernel (with an
+optional ramdisk) and device tree chosen from various options in the FIT.
+Now that U-Boot supports configuration via device tree, it is possible to
+load U-Boot from a FIT, with the device tree chosen by SPL.
+
+Binman considers FIT to be one of the binaries it can place in the image.
+
+Where possible it is best to put as much as possible in the FIT, with binman
+used to deal with cases not covered by FIT. Examples include initial
+execution (since FIT itself does not have an executable header) and dealing
+with device boundaries, such as the read-only/read-write separation in SPI
+flash.
+
+For U-Boot, binman should not be used to create ad-hoc images in place of
+FIT.
+
+
+Relationship to mkimage
+-----------------------
+
+The mkimage tool provides a means to create a FIT. Traditionally it has
+needed an image description file: a device tree, like binman, but in a
+different format. More recently it has started to support a '-f auto' mode
+which can generate that automatically.
+
+More relevant to binman, mkimage also permits creation of many SoC-specific
+image types. These can be listed by running 'mkimage -T list'. Examples
+include 'rksd', the Rockchip SD/MMC boot format. The mkimage tool is often
+called from the U-Boot build system for this reason.
+
+Binman considers the output files created by mkimage to be binary blobs
+which it can place in an image. Binman does not replace the mkimage tool or
+this purpose. It would be possible in some situtions to create a new entry
+type for the images in mkimage, but this would not add functionality. It
+seems better to use the mkiamge tool to generate binaries and avoid blurring
+the boundaries between building input files (mkimage) and packaging then
+into a final image (binman).
+
+
+Example use of binman in U-Boot
+-------------------------------
+
+Binman aims to replace some of the ad-hoc image creation in the U-Boot
+build system.
+
+Consider sunxi. It has the following steps:
+
+1. It uses a custom mksunxiboot tool to build an SPL image called
+sunxi-spl.bin. This should probably move into mkimage.
+
+2. It uses mkimage to package U-Boot into a legacy image file (so that it can
+hold the load and execution address) called u-boot.img.
+
+3. It builds a final output image called u-boot-sunxi-with-spl.bin which
+consists of sunxi-spl.bin, some padding and u-boot.img.
+
+Binman is intended to replace the last step. The U-Boot build system builds
+u-boot.bin and sunxi-spl.bin. Binman can then take over creation of
+sunxi-spl.bin (by calling mksunxiboot, or hopefully one day mkimage). In any
+case, it would then create the image from the component parts.
+
+This simplifies the U-Boot Makefile somewhat, since various pieces of logic
+can be replaced by a call to binman.
+
+
+Example use of binman for x86
+-----------------------------
+
+In most cases x86 images have a lot of binary blobs, 'black-box' code
+provided by Intel which must be run for the platform to work. Typically
+these blobs are not relocatable and must be placed at fixed areas in the
+firmare image.
+
+Currently this is handled by ifdtool, which places microcode, FSP, MRC, VGA
+BIOS, reference code and Intel ME binaries into a u-boot.rom file.
+
+Binman is intended to replace all of this, with ifdtool left to handle only
+the configuration of the Intel-format descriptor.
+
+
+Running binman
+--------------
+
+Type:
+
+	binman -b <board_name>
+
+to build an image for a board. The board name is the same name used when
+configuring U-Boot (e.g. for sandbox_defconfig the board name is 'sandbox').
+Binman assumes that the input files for the build are in ../b/<board_name>.
+
+Or you can specify this explicitly:
+
+	binman -I <build_path>
+
+where <build_path> is the build directory containing the output of the U-Boot
+build.
+
+(Future work will make this more configurable)
+
+In either case, binman picks up the device tree file (u-boot.dtb) and looks
+for its instructions in the 'binman' node.
+
+Binman has a few other options which you can see by running 'binman -h'.
+
+
+Image description format
+------------------------
+
+The binman node is called 'binman'. An example image description is shown
+below:
+
+	binman {
+		filename = "u-boot-sunxi-with-spl.bin";
+		pad-byte = <0xff>;
+		blob {
+			filename = "spl/sunxi-spl.bin";
+		};
+		u-boot {
+			pos = <CONFIG_SPL_PAD_TO>;
+		};
+	};
+
+
+This requests binman to create an image file called u-boot-sunxi-with-spl.bin
+consisting of a specially formatted SPL (spl/sunxi-spl.bin, built by the
+normal U-Boot Makefile), some 0xff padding, and a U-Boot legacy image. The
+padding comes from the fact that the second binary is placed at
+CONFIG_SPL_PAD_TO. If that line were omitted then the U-Boot binary would
+immediately follow the SPL binary.
+
+The binman node describes an image. The sub-nodes describe entries in the
+image. Each entry represents a region within the overall image. The name of
+the entry (blob, u-boot) tells binman what to put there. For 'blob' we must
+provide a filename. For 'u-boot', binman knows that this means 'u-boot.bin'.
+
+Entries are normally placed into the image sequentially, one after the other.
+The image size is the total size of all entries. As you can see, you can
+specify the start position of an entry using the 'pos' property.
+
+Note that due to a device tree requirement, all entries must have a unique
+name. If you want to put the same binary in the image multiple times, you can
+use any unique name, with the 'type' property providing the type.
+
+The attributes supported for entries are described below.
+
+pos:
+	This sets the position of an entry within the image. The first byte
+	of the image is normally at position 0. If 'pos' is not provided,
+	binman sets it to the end of the previous region, or the start of
+	the image's entry area (normally 0) if there is no previous region.
+
+align:
+	This sets the alignment of the entry. The entry position is adjusted
+	so that the entry starts on an aligned boundary within the image. For
+	example 'align = <16>' means that the entry will start on a 16-byte
+	boundary. Alignment shold be a power of 2. If 'align' is not
+	provided, no alignment is performed.
+
+size:
+	This sets the size of the entry. The contents will be padded out to
+	this size. If this is not provided, it will be set to the size of the
+	contents.
+
+pad-before:
+	Padding before the contents of the entry. Normally this is 0, meaning
+	that the contents start at the beginning of the entry. This can be
+	offset the entry contents a little. Defaults to 0.
+
+pad-after:
+	Padding after the contents of the entry. Normally this is 0, meaning
+	that the entry ends at the last byte of content (unless adjusted by
+	other properties). This allows room to be created in the image for
+	this entry to expand later. Defaults to 0.
+
+align-size:
+	This sets the alignment of the entry size. For example, to ensure
+	that the size of an entry is a multiple of 64 bytes, set this to 64.
+	If 'align-size' is not provided, no alignment is performed.
+
+align-end:
+	This sets the alignment of the end of an entry. Some entries require
+	that they end on an alignment boundary, regardless of where they
+	start. If 'align-end' is not provided, no alignment is performed.
+
+	Note: This is not yet implemented in binman.
+
+filename:
+	For 'blob' types this provides the filename containing the binary to
+	put into the entry. If binman knows about the entry type (like
+	u-boot-bin), then there is no need to specify this.
+
+type:
+	Sets the type of an entry. This defaults to the entry name, but it is
+	possible to use any name, and then add (for example) 'type = "u-boot"'
+	to specify the type.
+
+
+The attributes supported for images are described below. Several are similar
+to those for entries.
+
+size:
+	Sets the image size in bytes, for example 'size = <0x100000>' for a
+	1MB image.
+
+align-size:
+	This sets the alignment of the image size. For example, to ensure
+	that the image ends on a 512-byte boundary, use 'align-size = <512>'.
+	If 'align-size' is not provided, no alignment is performed.
+
+pad-before:
+	This sets the padding before the image entries. The first entry will
+	be positionad after the padding. This defaults to 0.
+
+pad-after:
+	This sets the padding after the image entries. The padding will be
+	placed after the last entry. This defaults to 0.
+
+pad-byte:
+	This specifies the pad byte to use when padding in the image. It
+	defaults to 0. To use 0xff, you would add 'pad-byte = <0xff>'.
+
+filename:
+	This specifies the image filename. It defaults to 'image.bin'.
+
+sort-by-pos:
+	This causes binman to reorder the entries as needed to make sure they
+	are in increasing positional order. This can be used when your entry
+	order may not match the positional order. A common situation is where
+	the 'pos' properties are set by CONFIG options, so their ordering is
+	not known a priori.
+
+	This is a boolean property so needs no value. To enable it, add a
+	line 'sort-by-pos;' to your description.
+
+multiple-images:
+	Normally only a single image is generated. To create more than one
+	image, put this property in the binman node. For example, this will
+	create image1.bin containing u-boot.bin, and image2.bin containing
+	both spl/u-boot-spl.bin and u-boot.bin:
+
+	binman {
+		multiple-images;
+		image1 {
+			u-boot {
+			};
+		};
+
+		image2 {
+			spl {
+			};
+			u-boot {
+			};
+		};
+	};
+
+end-at-4gb:
+	For x86 machines the ROM positions start just before 4GB and extend
+	up so that the image finished at the 4GB boundary. This boolean
+	option can be enabled to support this. The image size must be
+	provided so that binman knows when the image should start. For an
+	8MB ROM, the position of the first entry would be 0xfff80000 with
+	this option, instead of 0 without this option.
+
+
+Examples of the above options can be found in the tests. See the
+tools/binman/test directory.
+
+
+Order of image creation
+-----------------------
+
+Image creation proceeds in the following order, for each entry in the image.
+
+1. GetEntryContents() - the contents of each entry are obtained, normally by
+reading from a file. This calls the Entry.ObtainContents() to read the
+contents. The default version of Entry.ObtainContents() calls
+Entry.GetDefaultFilename() and then reads that file. So a common mechanism
+to select a file to read is to override that function in the subclass. The
+functions must return True when they have read the contents. Binman will
+retry calling the functions a few times if False is returned, allowing
+dependencies between the contents of different entries.
+
+2. GetEntryPositions() - calls Entry.GetPositions() for each entry. This can
+return a dict containing entries that need updating. The key should be the
+entry name and the value is a tuple (pos, size). This allows an entry to
+provide the position and size for other entries. The default implementation
+of GetEntryPositions() returns {}.
+
+3. PackEntries() - calls Entry.Pack() which figures out the position and
+size of an entry. The 'current' image position is passed in, and the function
+returns the position immediately after the entry being packed. The default
+implementation of Pack() is usually sufficient.
+
+4. CheckSize() - checks that the contents of all the entries fits within
+the image size. If the image does not have a defined size, the size is set
+large enough to hold all the entries.
+
+5. CheckEntries() - checks that the entries do not overlap, nor extend
+outside the image.
+
+6. ProcessEntryContents() - this calls Entry.ProcessContents() on each entry.
+The default implementatoin does nothing. This can be overriden to adjust the
+contents of an entry in some way. For example, it would be possible to create
+an entry containing a hash of the contents of some other entries. At this
+stage the position and size of entries should not be adjusted.
+
+7. BuildImage() - builds the image and writes it to a file. This is the final
+step.
+
+
+Advanced Features / Technical docs
+----------------------------------
+
+The behaviour of entries is defined by the Entry class. All other entries are
+a subclass of this. An important subclass is Entry_blob which takes binary
+data from a file and places it in the entry. In fact most entry types are
+subclasses of Entry_blob.
+
+Each entry type is a separate file in the tools/binman/etype directory. Each
+file contains a class called Entry_<type> where <type> is the entry type.
+New entry types can be supported by adding new files in that directory.
+These will automatically be detected by binman when needed.
+
+Entry properties are documented in entry.py. The entry subclasses are free
+to change the values of properties to support special behaviour. For example,
+when Entry_blob loads a file, it sets content_size to the size of the file.
+Entry classes can adjust other entries. For example, an entry that knows
+where other entries should be positioned can set up those entries' positions
+so they don't need to be set in the binman decription. It can also adjust
+entry contents.
+
+Most of the time such essoteric behaviour is not needed, but it can be
+essential for complex images.
+
+
+History / Credits
+-----------------
+
+Binman takes a lot of inspiration from a Chrome OS tool called
+'cros_bundle_firmware', which I wrote some years ago. That tool was based on
+a reasonably simple and sound design but has expanded greatly over the
+years. In particular its handling of x86 images is convoluted.
+
+Quite a few lessons have been learned which are hopefully be applied here.
+
+
+Design notes
+------------
+
+On the face of it, a tool to create firmware images should be fairly simple:
+just find all the input binaries and place them at the right place in the
+image. The difficulty comes from the wide variety of input types (simple
+flat binaries containing code, packaged data with various headers), packing
+requirments (alignment, spacing, device boundaries) and other required
+features such as hierarchical images.
+
+The design challenge is to make it easy to create simple images, while
+allowing the more complex cases to be supported. For example, for most
+images we don't much care exactly where each binary ends up, so we should
+not have to specify that unnecessarily.
+
+New entry types should aim to provide simple usage where possible. If new
+core features are needed, they can be added in the Entry base class.
+
+
+To do
+-----
+
+Some ideas:
+- Fill out the device tree to include the final position and size of each
+  entry (since the input file may not always specify these)
+- Use of-platdata to make the information available to code that is unable
+  to use device tree (such as a very small SPL image)
+- Write an image map to a text file
+- Allow easy building of images by specifying just the board name
+- Produce a full Python binding for libfdt (for upstream)
+- Add an option to decode an image into the constituent binaries
+- Suppoort hierarchical images (packing of binaries into another binary
+  which is then placed in the image)
+- Support building an image for a board (-b) more completely, with a
+  configurable build directory
+- Consider making binman work with buildman, although if it is used in the
+  Makefile, this will be automatic
+- Implement align-end
+
+--
+Simon Glass <sjg@chromium.org>
+7/7/2016
diff --git a/tools/binman/binman b/tools/binman/binman
new file mode 120000
index 0000000..979b7e4
--- /dev/null
+++ b/tools/binman/binman
@@ -0,0 +1 @@
+binman.py
\ No newline at end of file
diff --git a/tools/binman/binman.py b/tools/binman/binman.py
new file mode 100755
index 0000000..7fb67cb
--- /dev/null
+++ b/tools/binman/binman.py
@@ -0,0 +1,114 @@
+#!/usr/bin/python
+
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+# Creates binary images from input files controlled by a description
+#
+
+"""See README for more information"""
+
+import os
+import sys
+import traceback
+import unittest
+
+# Bring in the patman and dtoc libraries
+our_path = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(our_path, '../patman'))
+sys.path.append(os.path.join(our_path, '../dtoc'))
+
+# Also allow entry-type modules to be brought in from the etype directory.
+sys.path.append(os.path.join(our_path, 'etype'))
+
+import cmdline
+import command
+import control
+
+def RunTests():
+    """Run the functional tests and any embedded doctests"""
+    import entry_test
+    import fdt_test
+    import func_test
+    import test
+    import doctest
+
+    result = unittest.TestResult()
+    for module in []:
+        suite = doctest.DocTestSuite(module)
+        suite.run(result)
+
+    sys.argv = [sys.argv[0]]
+    for module in (func_test.TestFunctional, fdt_test.TestFdt,
+                   entry_test.TestEntry):
+        suite = unittest.TestLoader().loadTestsFromTestCase(module)
+        suite.run(result)
+
+    print result
+    for test, err in result.errors:
+        print test.id(), err
+    for test, err in result.failures:
+        print err
+
+def RunTestCoverage():
+    """Run the tests and check that we get 100% coverage"""
+    # This uses the build output from sandbox_spl to get _libfdt.so
+    cmd = ('PYTHONPATH=%s/sandbox_spl/tools coverage run '
+            '--include "tools/binman/*.py" --omit "*test*,*binman.py" '
+            'tools/binman/binman.py -t' % options.build_dir)
+    os.system(cmd)
+    stdout = command.Output('coverage', 'report')
+    coverage = stdout.splitlines()[-1].split(' ')[-1]
+    if coverage != '100%':
+        print stdout
+        print "Type 'coverage html' to get a report in htmlcov/index.html"
+        raise ValueError('Coverage error: %s, but should be 100%%' % coverage)
+
+
+def RunBinman(options, args):
+    """Main entry point to binman once arguments are parsed
+
+    Args:
+        options: Command-line options
+        args: Non-option arguments
+    """
+    ret_code = 0
+
+    # For testing: This enables full exception traces.
+    #options.debug = True
+
+    if not options.debug:
+        sys.tracebacklimit = 0
+
+    if options.test:
+        RunTests()
+
+    elif options.test_coverage:
+        RunTestCoverage()
+
+    elif options.full_help:
+        pager = os.getenv('PAGER')
+        if not pager:
+            pager = 'more'
+        fname = os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])),
+                            'README')
+        command.Run(pager, fname)
+
+    else:
+        try:
+            ret_code = control.Binman(options, args)
+        except Exception as e:
+            print 'binman: %s' % e
+            if options.debug:
+                print
+                traceback.print_exc()
+            ret_code = 1
+    return ret_code
+
+
+if __name__ == "__main__":
+    (options, args) = cmdline.ParseArgs(sys.argv)
+    ret_code = RunBinman(options, args)
+    sys.exit(ret_code)
diff --git a/tools/binman/cmdline.py b/tools/binman/cmdline.py
new file mode 100644
index 0000000..233d5e1
--- /dev/null
+++ b/tools/binman/cmdline.py
@@ -0,0 +1,53 @@
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Command-line parser for binman
+#
+
+from optparse import OptionParser
+
+def ParseArgs(argv):
+    """Parse the binman command-line arguments
+
+    Args:
+        argv: List of string arguments
+    Returns:
+        Tuple (options, args) with the command-line options and arugments.
+            options provides access to the options (e.g. option.debug)
+            args is a list of string arguments
+    """
+    parser = OptionParser()
+    parser.add_option('-b', '--board', type='string',
+            help='Board name to build')
+    parser.add_option('-B', '--build-dir', type='string', default='b',
+            help='Directory containing the build output')
+    parser.add_option('-d', '--dt', type='string',
+            help='Configuration file (.dtb) to use')
+    parser.add_option('-D', '--debug', action='store_true',
+            help='Enabling debugging (provides a full traceback on error)')
+    parser.add_option('-I', '--indir', action='append',
+            help='Add a path to a directory to use for input files')
+    parser.add_option('-H', '--full-help', action='store_true',
+        default=False, help='Display the README file')
+    parser.add_option('-O', '--outdir', type='string',
+        action='store', help='Path to directory to use for intermediate and '
+        'output files')
+    parser.add_option('-p', '--preserve', action='store_true',\
+        help='Preserve temporary output directory even if option -O is not '
+             'given')
+    parser.add_option('-t', '--test', action='store_true',
+                    default=False, help='run tests')
+    parser.add_option('-T', '--test-coverage', action='store_true',
+                    default=False, help='run tests and check for 100% coverage')
+    parser.add_option('-v', '--verbosity', default=1,
+        type='int', help='Control verbosity: 0=silent, 1=progress, 3=full, '
+        '4=debug')
+
+    parser.usage += """
+
+Create images for a board from a set of binaries. It is controlled by a
+description in the board device tree."""
+
+    return parser.parse_args(argv)
diff --git a/tools/binman/control.py b/tools/binman/control.py
new file mode 100644
index 0000000..e909678
--- /dev/null
+++ b/tools/binman/control.py
@@ -0,0 +1,118 @@
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Creates binary images from input files controlled by a description
+#
+
+from collections import OrderedDict
+import os
+import sys
+import tools
+
+import command
+import fdt_select
+import fdt_util
+from image import Image
+import tout
+
+# List of images we plan to create
+# Make this global so that it can be referenced from tests
+images = OrderedDict()
+
+def _ReadImageDesc(binman_node):
+    """Read the image descriptions from the /binman node
+
+    This normally produces a single Image object called 'image'. But if
+    multiple images are present, they will all be returned.
+
+    Args:
+        binman_node: Node object of the /binman node
+    Returns:
+        OrderedDict of Image objects, each of which describes an image
+    """
+    images = OrderedDict()
+    if 'multiple-images' in binman_node.props:
+        for node in binman_node.subnodes:
+            images[node.name] = Image(node.name, node)
+    else:
+        images['image'] = Image('image', binman_node)
+    return images
+
+def _FindBinmanNode(fdt):
+    """Find the 'binman' node in the device tree
+
+    Args:
+        fdt: Fdt object to scan
+    Returns:
+        Node object of /binman node, or None if not found
+    """
+    for node in fdt.GetRoot().subnodes:
+        if node.name == 'binman':
+            return node
+    return None
+
+def Binman(options, args):
+    """The main control code for binman
+
+    This assumes that help and test options have already been dealt with. It
+    deals with the core task of building images.
+
+    Args:
+        options: Command line options object
+        args: Command line arguments (list of strings)
+    """
+    global images
+
+    if options.full_help:
+        pager = os.getenv('PAGER')
+        if not pager:
+            pager = 'more'
+        fname = os.path.join(os.path.dirname(os.path.realpath(sys.argv[0])),
+                            'README')
+        command.Run(pager, fname)
+        return 0
+
+    # Try to figure out which device tree contains our image description
+    if options.dt:
+        dtb_fname = options.dt
+    else:
+        board = options.board
+        if not board:
+            raise ValueError('Must provide a board to process (use -b <board>)')
+        board_pathname = os.path.join(options.build_dir, board)
+        dtb_fname = os.path.join(board_pathname, 'u-boot.dtb')
+        if not options.indir:
+            options.indir = ['.']
+        options.indir.append(board_pathname)
+
+    try:
+        tout.Init(options.verbosity)
+        try:
+            tools.SetInputDirs(options.indir)
+            tools.PrepareOutputDir(options.outdir, options.preserve)
+            fdt = fdt_select.FdtScan(dtb_fname)
+            node = _FindBinmanNode(fdt)
+            if not node:
+                raise ValueError("Device tree '%s' does not have a 'binman' "
+                                 "node" % dtb_fname)
+            images = _ReadImageDesc(node)
+            for image in images.values():
+                # Perform all steps for this image, including checking and
+                # writing it. This means that errors found with a later
+                # image will be reported after earlier images are already
+                # completed and written, but that does not seem important.
+                image.GetEntryContents()
+                image.GetEntryPositions()
+                image.PackEntries()
+                image.CheckSize()
+                image.CheckEntries()
+                image.ProcessEntryContents()
+                image.BuildImage()
+        finally:
+            tools.FinaliseOutputDir()
+    finally:
+        tout.Uninit()
+
+    return 0
diff --git a/tools/binman/etype/entry.py b/tools/binman/etype/entry.py
new file mode 100644
index 0000000..67c5734
--- /dev/null
+++ b/tools/binman/etype/entry.py
@@ -0,0 +1,200 @@
+# Copyright (c) 2016 Google, Inc
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Base class for all entries
+#
+
+# importlib was introduced in Python 2.7 but there was a report of it not
+# working in 2.7.12, so we work around this:
+# http://lists.denx.de/pipermail/u-boot/2016-October/269729.html
+try:
+    import importlib
+    have_importlib = True
+except:
+    have_importlib = False
+
+import fdt_util
+import tools
+
+modules = {}
+
+class Entry(object):
+    """An Entry in the image
+
+    An entry corresponds to a single node in the device-tree description
+    of the image. Each entry ends up being a part of the final image.
+    Entries can be placed either right next to each other, or with padding
+    between them. The type of the entry determines the data that is in it.
+
+    This class is not used by itself. All entry objects are subclasses of
+    Entry.
+
+    Attributes:
+        image: The image containing this entry
+        node: The node that created this entry
+        pos: Absolute position of entry within the image, None if not known
+        size: Entry size in bytes, None if not known
+        contents_size: Size of contents in bytes, 0 by default
+        align: Entry start position alignment, or None
+        align_size: Entry size alignment, or None
+        align_end: Entry end position alignment, or None
+        pad_before: Number of pad bytes before the contents, 0 if none
+        pad_after: Number of pad bytes after the contents, 0 if none
+        data: Contents of entry (string of bytes)
+    """
+    def __init__(self, image, etype, node, read_node=True):
+        self.image = image
+        self.etype = etype
+        self._node = node
+        self.pos = None
+        self.size = None
+        self.contents_size = 0
+        self.align = None
+        self.align_size = None
+        self.align_end = None
+        self.pad_before = 0
+        self.pad_after = 0
+        self.pos_unset = False
+        if read_node:
+            self.ReadNode()
+
+    @staticmethod
+    def Create(image, node, etype=None):
+        """Create a new entry for a node.
+
+        Args:
+            image:  Image object containing this node
+            node:   Node object containing information about the entry to create
+            etype:  Entry type to use, or None to work it out (used for tests)
+
+        Returns:
+            A new Entry object of the correct type (a subclass of Entry)
+        """
+        if not etype:
+            etype = fdt_util.GetString(node, 'type', node.name)
+        module_name = etype.replace('-', '_')
+        module = modules.get(module_name)
+
+        # Import the module if we have not already done so.
+        if not module:
+            try:
+                if have_importlib:
+                    module = importlib.import_module(module_name)
+                else:
+                    module = __import__(module_name)
+            except ImportError:
+                raise ValueError("Unknown entry type '%s' in node '%s'" %
+                        (etype, node.path))
+            modules[module_name] = module
+
+        # Call its constructor to get the object we want.
+        obj = getattr(module, 'Entry_%s' % module_name)
+        return obj(image, etype, node)
+
+    def ReadNode(self):
+        """Read entry information from the node
+
+        This reads all the fields we recognise from the node, ready for use.
+        """
+        self.pos = fdt_util.GetInt(self._node, 'pos')
+        self.size = fdt_util.GetInt(self._node, 'size')
+        self.align = fdt_util.GetInt(self._node, 'align')
+        if tools.NotPowerOfTwo(self.align):
+            raise ValueError("Node '%s': Alignment %s must be a power of two" %
+                             (self._node.path, self.align))
+        self.pad_before = fdt_util.GetInt(self._node, 'pad-before', 0)
+        self.pad_after = fdt_util.GetInt(self._node, 'pad-after', 0)
+        self.align_size = fdt_util.GetInt(self._node, 'align-size')
+        if tools.NotPowerOfTwo(self.align_size):
+            raise ValueError("Node '%s': Alignment size %s must be a power "
+                             "of two" % (self._node.path, self.align_size))
+        self.align_end = fdt_util.GetInt(self._node, 'align-end')
+        self.pos_unset = fdt_util.GetBool(self._node, 'pos-unset')
+
+    def ObtainContents(self):
+        """Figure out the contents of an entry.
+
+        Returns:
+            True if the contents were found, False if another call is needed
+            after the other entries are processed.
+        """
+        # No contents by default: subclasses can implement this
+        return True
+
+    def Pack(self, pos):
+        """Figure out how to pack the entry into the image
+
+        Most of the time the entries are not fully specified. There may be
+        an alignment but no size. In that case we take the size from the
+        contents of the entry.
+
+        If an entry has no hard-coded position, it will be placed at @pos.
+
+        Once this function is complete, both the position and size of the
+        entry will be know.
+
+        Args:
+            Current image position pointer
+
+        Returns:
+            New image position pointer (after this entry)
+        """
+        if self.pos is None:
+            if self.pos_unset:
+                self.Raise('No position set with pos-unset: should another '
+                           'entry provide this correct position?')
+            self.pos = tools.Align(pos, self.align)
+        needed = self.pad_before + self.contents_size + self.pad_after
+        needed = tools.Align(needed, self.align_size)
+        size = self.size
+        if not size:
+            size = needed
+        new_pos = self.pos + size
+        aligned_pos = tools.Align(new_pos, self.align_end)
+        if aligned_pos != new_pos:
+            size = aligned_pos - self.pos
+            new_pos = aligned_pos
+
+        if not self.size:
+            self.size = size
+
+        if self.size < needed:
+            self.Raise("Entry contents size is %#x (%d) but entry size is "
+                       "%#x (%d)" % (needed, needed, self.size, self.size))
+        # Check that the alignment is correct. It could be wrong if the
+        # and pos or size values were provided (i.e. not calculated), but
+        # conflict with the provided alignment values
+        if self.size != tools.Align(self.size, self.align_size):
+            self.Raise("Size %#x (%d) does not match align-size %#x (%d)" %
+                  (self.size, self.size, self.align_size, self.align_size))
+        if self.pos != tools.Align(self.pos, self.align):
+            self.Raise("Position %#x (%d) does not match align %#x (%d)" %
+                  (self.pos, self.pos, self.align, self.align))
+
+        return new_pos
+
+    def Raise(self, msg):
+        """Convenience function to raise an error referencing a node"""
+        raise ValueError("Node '%s': %s" % (self._node.path, msg))
+
+    def GetPath(self):
+        """Get the path of a node
+
+        Returns:
+            Full path of the node for this entry
+        """
+        return self._node.path
+
+    def GetData(self):
+        return self.data
+
+    def GetPositions(self):
+        return {}
+
+    def SetPositionSize(self, pos, size):
+        self.pos = pos
+        self.size = size
+
+    def ProcessContents(self):
+        pass
diff --git a/tools/binman/fdt_test.py b/tools/binman/fdt_test.py
new file mode 100644
index 0000000..1d9494e
--- /dev/null
+++ b/tools/binman/fdt_test.py
@@ -0,0 +1,48 @@
+#
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Test for the fdt modules
+
+import os
+import sys
+import tempfile
+import unittest
+
+from fdt_select import FdtScan
+import fdt_util
+import tools
+
+class TestFdt(unittest.TestCase):
+    @classmethod
+    def setUpClass(self):
+        self._binman_dir = os.path.dirname(os.path.realpath(sys.argv[0]))
+        self._indir = tempfile.mkdtemp(prefix='binmant.')
+        tools.PrepareOutputDir(self._indir, True)
+
+    def TestFile(self, fname):
+        return os.path.join(self._binman_dir, 'test', fname)
+
+    def GetCompiled(self, fname):
+        return fdt_util.EnsureCompiled(self.TestFile(fname))
+
+    def _DeleteProp(self, fdt):
+        node = fdt.GetNode('/microcode/update@0')
+        node.DeleteProp('data')
+
+    def testFdtNormal(self):
+        fname = self.GetCompiled('34_x86_ucode.dts')
+        fdt = FdtScan(fname)
+        self._DeleteProp(fdt)
+
+    def testFdtFallback(self):
+        fname = self.GetCompiled('34_x86_ucode.dts')
+        fdt = FdtScan(fname, True)
+        fdt.GetProp('/microcode/update@0', 'data')
+        self.assertEqual('fred',
+            fdt.GetProp('/microcode/update@0', 'none', default='fred'))
+        self.assertEqual('12345678 12345679',
+            fdt.GetProp('/microcode/update@0', 'data', typespec='x'))
+        self._DeleteProp(fdt)
diff --git a/tools/binman/image.py b/tools/binman/image.py
new file mode 100644
index 0000000..07fc930
--- /dev/null
+++ b/tools/binman/image.py
@@ -0,0 +1,229 @@
+# Copyright (c) 2016 Google, Inc
+# Written by Simon Glass <sjg@chromium.org>
+#
+# SPDX-License-Identifier:      GPL-2.0+
+#
+# Class for an image, the output of binman
+#
+
+from collections import OrderedDict
+from operator import attrgetter
+
+import entry
+from entry import Entry
+import fdt_util
+import tools
+
+class Image:
+    """A Image, representing an output from binman
+
+    An image is comprised of a collection of entries each containing binary
+    data. The image size must be large enough to hold all of this data.
+
+    This class implements the various operations needed for images.
+
+    Atrtributes:
+        _node: Node object that contains the image definition in device tree
+        _name: Image name
+        _size: Image size in bytes, or None if not known yet
+        _align_size: Image size alignment, or None
+        _pad_before: Number of bytes before the first entry starts. This
+            effectively changes the place where entry position 0 starts
+        _pad_after: Number of bytes after the last entry ends. The last
+            entry will finish on or before this boundary
+        _pad_byte: Byte to use to pad the image where there is no entry
+        _filename: Output filename for image
+        _sort: True if entries should be sorted by position, False if they
+            must be in-order in the device tree description
+        _skip_at_start: Number of bytes before the first entry starts. These
+            effecively adjust the starting position of entries. For example,
+            if _pad_before is 16, then the first entry would start at 16.
+            An entry with pos = 20 would in fact be written at position 4
+            in the image file.
+        _end_4gb: Indicates that the image ends at the 4GB boundary. This is
+            used for x86 images, which want to use positions such that a
+             memory address (like 0xff800000) is the first entry position.
+             This causes _skip_at_start to be set to the starting memory
+             address.
+        _entries: OrderedDict() of entries
+    """
+    def __init__(self, name, node):
+        self._node = node
+        self._name = name
+        self._size = None
+        self._align_size = None
+        self._pad_before = 0
+        self._pad_after = 0
+        self._pad_byte = 0
+        self._filename = '%s.bin' % self._name
+        self._sort = False
+        self._skip_at_start = 0
+        self._end_4gb = False
+        self._entries = OrderedDict()
+
+        self._ReadNode()
+        self._ReadEntries()
+
+    def _ReadNode(self):
+        """Read properties from the image node"""
+        self._size = fdt_util.GetInt(self._node, 'size')
+        self._align_size = fdt_util.GetInt(self._node, 'align-size')
+        if tools.NotPowerOfTwo(self._align_size):
+            self._Raise("Alignment size %s must be a power of two" %
+                        self._align_size)
+        self._pad_before = fdt_util.GetInt(self._node, 'pad-before', 0)
+        self._pad_after = fdt_util.GetInt(self._node, 'pad-after', 0)
+        self._pad_byte = fdt_util.GetInt(self._node, 'pad-byte', 0)
+        filename = fdt_util.GetString(self._node, 'filename')
+        if filename:
+            self._filename = filename
+        self._sort = fdt_util.GetBool(self._node, 'sort-by-pos')
+        self._end_4gb = fdt_util.GetBool(self._node, 'end-at-4gb')
+        if self._end_4gb and not self._size:
+            self._Raise("Image size must be provided when using end-at-4gb")
+        if self._end_4gb:
+            self._skip_at_start = 0x100000000 - self._size
+
+    def CheckSize(self):
+        """Check that the image contents does not exceed its size, etc."""
+        contents_size = 0
+        for entry in self._entries.values():
+            contents_size = max(contents_size, entry.pos + entry.size)
+
+        contents_size -= self._skip_at_start
+
+        size = self._size
+        if not size:
+            size = self._pad_before + contents_size + self._pad_after
+            size = tools.Align(size, self._align_size)
+
+        if self._size and contents_size > self._size:
+            self._Raise("contents size %#x (%d) exceeds image size %#x (%d)" %
+                       (contents_size, contents_size, self._size, self._size))
+        if not self._size:
+            self._size = size
+        if self._size != tools.Align(self._size, self._align_size):
+            self._Raise("Size %#x (%d) does not match align-size %#x (%d)" %
+                  (self._size, self._size, self._align_size, self._align_size))
+
+    def _Raise(self, msg):
+        """Raises an error for this image
+
+        Args:
+            msg: Error message to use in the raise string
+        Raises:
+            ValueError()
+        """
+        raise ValueError("Image '%s': %s" % (self._node.path, msg))
+
+    def _ReadEntries(self):
+        for node in self._node.subnodes:
+            self._entries[node.name] = Entry.Create(self, node)
+
+    def FindEntryType(self, etype):
+        """Find an entry type in the image
+
+        Args:
+            etype: Entry type to find
+        Returns:
+            entry matching that type, or None if not found
+        """
+        for entry in self._entries.values():
+            if entry.etype == etype:
+                return entry
+        return None
+
+    def GetEntryContents(self):
+        """Call ObtainContents() for each entry
+
+        This calls each entry's ObtainContents() a few times until they all
+        return True. We stop calling an entry's function once it returns
+        True. This allows the contents of one entry to depend on another.
+
+        After 3 rounds we give up since it's likely an error.
+        """
+        todo = self._entries.values()
+        for passnum in range(3):
+            next_todo = []
+            for entry in todo:
+                if not entry.ObtainContents():
+                    next_todo.append(entry)
+            todo = next_todo
+            if not todo:
+                break
+
+    def _SetEntryPosSize(self, name, pos, size):
+        """Set the position and size of an entry
+
+        Args:
+            name: Entry name to update
+            pos: New position
+            size: New size
+        """
+        entry = self._entries.get(name)
+        if not entry:
+            self._Raise("Unable to set pos/size for unknown entry '%s'" % name)
+        entry.SetPositionSize(self._skip_at_start + pos, size)
+
+    def GetEntryPositions(self):
+        """Handle entries that want to set the position/size of other entries
+
+        This calls each entry's GetPositions() method. If it returns a list
+        of entries to update, it updates them.
+        """
+        for entry in self._entries.values():
+            pos_dict = entry.GetPositions()
+            for name, info in pos_dict.iteritems():
+                self._SetEntryPosSize(name, *info)
+
+    def PackEntries(self):
+        """Pack all entries into the image"""
+        pos = self._skip_at_start
+        for entry in self._entries.values():
+            pos = entry.Pack(pos)
+
+    def _SortEntries(self):
+        """Sort entries by position"""
+        entries = sorted(self._entries.values(), key=lambda entry: entry.pos)
+        self._entries.clear()
+        for entry in entries:
+            self._entries[entry._node.name] = entry
+
+    def CheckEntries(self):
+        """Check that entries do not overlap or extend outside the image"""
+        if self._sort:
+            self._SortEntries()
+        pos = 0
+        prev_name = 'None'
+        for entry in self._entries.values():
+            if (entry.pos < self._skip_at_start or
+                entry.pos >= self._skip_at_start + self._size):
+                entry.Raise("Position %#x (%d) is outside the image starting "
+                            "at %#x (%d)" %
+                            (entry.pos, entry.pos, self._skip_at_start,
+                             self._skip_at_start))
+            if entry.pos < pos:
+                entry.Raise("Position %#x (%d) overlaps with previous entry '%s' "
+                            "ending at %#x (%d)" %
+                            (entry.pos, entry.pos, prev_name, pos, pos))
+            pos = entry.pos + entry.size
+            prev_name = entry.GetPath()
+
+    def ProcessEntryContents(self):
+        """Call the ProcessContents() method for each entry
+
+        This is intended to adjust the contents as needed by the entry type.
+        """
+        for entry in self._entries.values():
+            entry.ProcessContents()
+
+    def BuildImage(self):
+        """Write the image to a file"""
+        fname = tools.GetOutputFilename(self._filename)
+        with open(fname, 'wb') as fd:
+            fd.write(chr(self._pad_byte) * self._size)
+
+            for entry in self._entries.values():
+                data = entry.GetData()
+                fd.seek(self._pad_before + entry.pos - self._skip_at_start)
+                fd.write(data)