sandbox: image: Create a test for loading FIT images

The image code is fairly complex with various different options. It would
be useful to have comprehensive tests for this.

As a start, create a script which tries out loading a kernel/ramdisk/fdt
from a FIT and checks that the images appear in the right place in memory.

This uses sandbox which now supports bootm and related features.

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

test/image/test-fit.py

@@ -0,0 +1,422 @@
+#!/usr/bin/python
+#
+# Copyright (c) 2013, Google Inc.
+#
+# Sanity check of the FIT handling in U-Boot
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License as
+# published by the Free Software Foundation; either version 2 of
+# the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+# MA 02111-1307 USA
+#
+# To run this:
+#
+# make O=sandbox sandbox_config
+# make O=sandbox
+# ./test/image/test-fit.py -u sandbox/u-boot
+
+import doctest
+from optparse import OptionParser
+import os
+import shutil
+import struct
+import sys
+import tempfile
+
+# The 'command' library in patman is convenient for running commands
+base_path = os.path.dirname(sys.argv[0])
+patman = os.path.join(base_path, '../../tools/patman')
+sys.path.append(patman)
+
+import command
+
+# Define a base ITS which we can adjust using % and a dictionary
+base_its = '''
+/dts-v1/;
+
+/ {
+        description = "Chrome OS kernel image with one or more FDT blobs";
+        #address-cells = <1>;
+
+        images {
+                kernel@1 {
+                        data = /incbin/("%(kernel)s");
+                        type = "kernel";
+                        arch = "sandbox";
+                        os = "linux";
+                        compression = "none";
+                        load = <0x40000>;
+                        entry = <0x8>;
+                };
+                fdt@1 {
+                        description = "snow";
+                        data = /incbin/("u-boot.dtb");
+                        type = "flat_dt";
+                        arch = "sandbox";
+                        %(fdt_load)s
+                        compression = "none";
+                        signature@1 {
+                                algo = "sha1,rsa2048";
+                                key-name-hint = "dev";
+                        };
+                };
+                ramdisk@1 {
+                        description = "snow";
+                        data = /incbin/("%(ramdisk)s");
+                        type = "ramdisk";
+                        arch = "sandbox";
+                        os = "linux";
+                        %(ramdisk_load)s
+                        compression = "none";
+                };
+        };
+        configurations {
+                default = "conf@1";
+                conf@1 {
+                        kernel = "kernel@1";
+                        fdt = "fdt@1";
+                        %(ramdisk_config)s
+                };
+        };
+};
+'''
+
+# Define a base FDT - currently we don't use anything in this
+base_fdt = '''
+/dts-v1/;
+
+/ {
+        model = "Sandbox Verified Boot Test";
+        compatible = "sandbox";
+
+};
+'''
+
+# This is the U-Boot script that is run for each test. First load the fit,
+# then do the 'bootm' command, then save out memory from the places where
+# we expect 'bootm' to write things. Then quit.
+base_script = '''
+sb load host 0 %(fit_addr)x %(fit)s
+fdt addr %(fit_addr)x
+bootm start %(fit_addr)x
+bootm loados
+sb save host 0 %(kernel_out)s %(kernel_addr)x %(kernel_size)x
+sb save host 0 %(fdt_out)s %(fdt_addr)x %(fdt_size)x
+sb save host 0 %(ramdisk_out)s %(ramdisk_addr)x %(ramdisk_size)x
+reset
+'''
+
+def make_fname(leaf):
+    """Make a temporary filename
+
+    Args:
+        leaf: Leaf name of file to create (within temporary directory)
+    Return:
+        Temporary filename
+    """
+    global base_dir
+
+    return os.path.join(base_dir, leaf)
+
+def filesize(fname):
+    """Get the size of a file
+
+    Args:
+        fname: Filename to check
+    Return:
+        Size of file in bytes
+    """
+    return os.stat(fname).st_size
+
+def read_file(fname):
+    """Read the contents of a file
+
+    Args:
+        fname: Filename to read
+    Returns:
+        Contents of file as a string
+    """
+    with open(fname, 'r') as fd:
+        return fd.read()
+
+def make_dtb():
+    """Make a sample .dts file and compile it to a .dtb
+
+    Returns:
+        Filename of .dtb file created
+    """
+    src = make_fname('u-boot.dts')
+    dtb = make_fname('u-boot.dtb')
+    with open(src, 'w') as fd:
+        print >>fd, base_fdt
+    command.Output('dtc', src, '-O', 'dtb', '-o', dtb)
+    return dtb
+
+def make_its(params):
+    """Make a sample .its file with parameters embedded
+
+    Args:
+        params: Dictionary containing parameters to embed in the %() strings
+    Returns:
+        Filename of .its file created
+    """
+    its = make_fname('test.its')
+    with open(its, 'w') as fd:
+        print >>fd, base_its % params
+    return its
+
+def make_fit(mkimage, params):
+    """Make a sample .fit file ready for loading
+
+    This creates a .its script with the selected parameters and uses mkimage to
+    turn this into a .fit image.
+
+    Args:
+        mkimage: Filename of 'mkimage' utility
+        params: Dictionary containing parameters to embed in the %() strings
+    Return:
+        Filename of .fit file created
+    """
+    fit = make_fname('test.fit')
+    its = make_its(params)
+    command.Output(mkimage, '-f', its, fit)
+    with open(make_fname('u-boot.dts'), 'w') as fd:
+        print >>fd, base_fdt
+    return fit
+
+def make_kernel():
+    """Make a sample kernel with test data
+
+    Returns:
+        Filename of kernel created
+    """
+    fname = make_fname('test-kernel.bin')
+    data = ''
+    for i in range(100):
+        data += 'this kernel %d is unlikely to boot\n' % i
+    with open(fname, 'w') as fd:
+        print >>fd, data
+    return fname
+
+def make_ramdisk():
+    """Make a sample ramdisk with test data
+
+    Returns:
+        Filename of ramdisk created
+    """
+    fname = make_fname('test-ramdisk.bin')
+    data = ''
+    for i in range(100):
+        data += 'ramdisk %d was seldom used in the middle ages\n' % i
+    with open(fname, 'w') as fd:
+        print >>fd, data
+    return fname
+
+def find_matching(text, match):
+    """Find a match in a line of text, and return the unmatched line portion
+
+    This is used to extract a part of a line from some text. The match string
+    is used to locate the line - we use the first line that contains that
+    match text.
+
+    Once we find a match, we discard the match string itself from the line,
+    and return what remains.
+
+    TODO: If this function becomes more generally useful, we could change it
+    to use regex and return groups.
+
+    Args:
+        text: Text to check (each line separated by \n)
+        match: String to search for
+    Return:
+        String containing unmatched portion of line
+    Exceptions:
+        ValueError: If match is not found
+
+    >>> find_matching('first line:10\\nsecond_line:20', 'first line:')
+    '10'
+    >>> find_matching('first line:10\\nsecond_line:20', 'second linex')
+    Traceback (most recent call last):
+      ...
+    ValueError: Test aborted
+    >>> find_matching('first line:10\\nsecond_line:20', 'second_line:')
+    '20'
+    """
+    for line in text.splitlines():
+        pos = line.find(match)
+        if pos != -1:
+            return line[:pos] + line[pos + len(match):]
+
+    print "Expected '%s' but not found in output:"
+    print text
+    raise ValueError('Test aborted')
+
+def set_test(name):
+    """Set the name of the current test and print a message
+
+    Args:
+        name: Name of test
+    """
+    global test_name
+
+    test_name = name
+    print name
+
+def fail(msg):
+    """Raise an error with a helpful failure message
+
+    Args:
+        msg: Message to display
+    """
+    raise ValueError("Test '%s' failed: %s" % (test_name, msg))
+
+def run_fit_test(mkimage, u_boot):
+    """Basic sanity check of FIT loading in U-Boot
+
+    TODO: Almost everything:
+       - hash algorithms - invalid hash/contents should be detected
+       - signature algorithms - invalid sig/contents should be detected
+       - compression
+       - checking that errors are detected like:
+            - image overwriting
+            - missing images
+            - invalid configurations
+            - incorrect os/arch/type fields
+            - empty data
+            - images too large/small
+            - invalid FDT (e.g. putting a random binary in instead)
+       - default configuration selection
+       - bootm command line parameters should have desired effect
+       - run code coverage to make sure we are testing all the code
+    """
+    global test_name
+
+    # Set up invariant files
+    control_dtb = make_dtb()
+    kernel = make_kernel()
+    ramdisk = make_ramdisk()
+    kernel_out = make_fname('kernel-out.bin')
+    fdt_out = make_fname('fdt-out.dtb')
+    ramdisk_out = make_fname('ramdisk-out.bin')
+
+    # Set up basic parameters with default values
+    params = {
+        'fit_addr' : 0x1000,
+
+        'kernel' : kernel,
+        'kernel_out' : kernel_out,
+        'kernel_addr' : 0x40000,
+        'kernel_size' : filesize(kernel),
+
+        'fdt_out' : fdt_out,
+        'fdt_addr' : 0x80000,
+        'fdt_size' : filesize(control_dtb),
+        'fdt_load' : '',
+
+        'ramdisk' : ramdisk,
+        'ramdisk_out' : ramdisk_out,
+        'ramdisk_addr' : 0xc0000,
+        'ramdisk_size' : filesize(ramdisk),
+        'ramdisk_load' : '',
+        'ramdisk_config' : '',
+    }
+
+    # Make a basic FIT and a script to load it
+    fit = make_fit(mkimage, params)
+    params['fit'] = fit
+    cmd = base_script % params
+
+    # First check that we can load a kernel
+    # We could perhaps reduce duplication with some loss of readability
+    set_test('Kernel load')
+    stdout = command.Output(u_boot, '-d', control_dtb, '-c', cmd)
+    if read_file(kernel) != read_file(kernel_out):
+        fail('Kernel not loaded')
+    if read_file(control_dtb) == read_file(fdt_out):
+        fail('FDT loaded but should be ignored')
+    if read_file(ramdisk) == read_file(ramdisk_out):
+        fail('Ramdisk loaded but should not be')
+
+    # Find out the offset in the FIT where U-Boot has found the FDT
+    line = find_matching(stdout, 'Booting using the fdt blob at ')
+    fit_offset = int(line, 16) - params['fit_addr']
+    fdt_magic = struct.pack('>L', 0xd00dfeed)
+    data = read_file(fit)
+
+    # Now find where it actually is in the FIT (skip the first word)
+    real_fit_offset = data.find(fdt_magic, 4)
+    if fit_offset != real_fit_offset:
+        fail('U-Boot loaded FDT from offset %#x, FDT is actually at %#x' %
+                (fit_offset, real_fit_offset))
+
+    # Now a kernel and an FDT
+    set_test('Kernel + FDT load')
+    params['fdt_load'] = 'load = <%#x>;' % params['fdt_addr']
+    fit = make_fit(mkimage, params)
+    stdout = command.Output(u_boot, '-d', control_dtb, '-c', cmd)
+    if read_file(kernel) != read_file(kernel_out):
+        fail('Kernel not loaded')
+    if read_file(control_dtb) != read_file(fdt_out):
+        fail('FDT not loaded')
+    if read_file(ramdisk) == read_file(ramdisk_out):
+        fail('Ramdisk loaded but should not be')
+
+    # Try a ramdisk
+    set_test('Kernel + FDT + Ramdisk load')
+    params['ramdisk_config'] = 'ramdisk = "ramdisk@1";'
+    params['ramdisk_load'] = 'load = <%#x>;' % params['ramdisk_addr']
+    fit = make_fit(mkimage, params)
+    stdout = command.Output(u_boot, '-d', control_dtb, '-c', cmd)
+    if read_file(ramdisk) != read_file(ramdisk_out):
+        fail('Ramdisk not loaded')
+
+def run_tests():
+    """Parse options, run the FIT tests and print the result"""
+    global base_path, base_dir
+
+    # Work in a temporary directory
+    base_dir = tempfile.mkdtemp()
+    parser = OptionParser()
+    parser.add_option('-u', '--u-boot',
+            default=os.path.join(base_path, 'u-boot'),
+            help='Select U-Boot sandbox binary')
+    parser.add_option('-k', '--keep', action='store_true',
+            help="Don't delete temporary directory even when tests pass")
+    parser.add_option('-t', '--selftest', action='store_true',
+            help='Run internal self tests')
+    (options, args) = parser.parse_args()
+
+    # Find the path to U-Boot, and assume mkimage is in its tools/mkimage dir
+    base_path = os.path.dirname(options.u_boot)
+    mkimage = os.path.join(base_path, 'tools/mkimage')
+
+    # There are a few doctests - handle these here
+    if options.selftest:
+        doctest.testmod()
+        return
+
+    title = 'FIT Tests'
+    print title, '\n', '=' * len(title)
+
+    run_fit_test(mkimage, options.u_boot)
+
+    print '\nTests passed'
+    print 'Caveat: this is only a sanity check - test coverage is poor'
+
+    # Remove the tempoerary directory unless we are asked to keep it
+    if options.keep:
+        print "Output files are in '%s'" % base_dir
+    else:
+        shutil.rmtree(base_dir)
+
+run_tests()