test/py/tests/test_fit.py

# Copyright (c) 2013, Google Inc.
#
# SPDX-License-Identifier:	GPL-2.0+
#
# Sanity check of the FIT handling in U-Boot

import os
import pytest
import struct
import u_boot_utils as util

# 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>;
                };
                kernel@2 {
                        data = /incbin/("%(loadables1)s");
                        type = "kernel";
                        arch = "sandbox";
                        os = "linux";
                        compression = "none";
                        %(loadables1_load)s
                        entry = <0x0>;
                };
                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";
                };
                ramdisk@2 {
                        description = "snow";
                        data = /incbin/("%(loadables2)s");
                        type = "ramdisk";
                        arch = "sandbox";
                        os = "linux";
                        %(loadables2_load)s
                        compression = "none";
                };
        };
        configurations {
                default = "conf@1";
                conf@1 {
                        kernel = "kernel@1";
                        fdt = "fdt@1";
                        %(ramdisk_config)s
                        %(loadables_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";

	reset@0 {
		compatible = "sandbox,reset";
	};

};
'''

# This is the U-Boot script that is run for each test. First load the FIT,
# then run the 'bootm' command, then save out memory from the places where
# we expect 'bootm' to write things. Then quit.
base_script = '''
sb load hostfs 0 %(fit_addr)x %(fit)s
fdt addr %(fit_addr)x
bootm start %(fit_addr)x
bootm loados
sb save hostfs 0 %(kernel_addr)x %(kernel_out)s %(kernel_size)x
sb save hostfs 0 %(fdt_addr)x %(fdt_out)s %(fdt_size)x
sb save hostfs 0 %(ramdisk_addr)x %(ramdisk_out)s %(ramdisk_size)x
sb save hostfs 0 %(loadables1_addr)x %(loadables1_out)s %(loadables1_size)x
sb save hostfs 0 %(loadables2_addr)x %(loadables2_out)s %(loadables2_size)x
'''

@pytest.mark.boardspec('sandbox')
@pytest.mark.buildconfigspec('fit_signature')
def test_fit(u_boot_console):
    def make_fname(leaf):
        """Make a temporary filename

        Args:
            leaf: Leaf name of file to create (within temporary directory)
        Return:
            Temporary filename
        """

        return os.path.join(cons.config.build_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
        util.run_and_log(cons, ['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)
        util.run_and_log(cons, [mkimage, '-f', its, fit])
        with open(make_fname('u-boot.dts'), 'w') as fd:
            print >> fd, base_fdt
        return fit

    def make_kernel(filename, text):
        """Make a sample kernel with test data

        Args:
            filename: the name of the file you want to create
        Returns:
            Full path and filename of the kernel it created
        """
        fname = make_fname(filename)
        data = ''
        for i in range(100):
            data += 'this %s %d is unlikely to boot\n' % (text, i)
        with open(fname, 'w') as fd:
            print >> fd, data
        return fname

    def make_ramdisk(filename, text):
        """Make a sample ramdisk with test data

        Returns:
            Filename of ramdisk created
        """
        fname = make_fname(filename)
        data = ''
        for i in range(100):
            data += '%s %d was seldom used in the middle ages\n' % (text, 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 (list of strings, one for each command issued)
            match: String to search for
        Return:
            String containing unmatched portion of line
        Exceptions:
            ValueError: If match is not found

        >>> find_matching(['first line:10', 'second_line:20'], 'first line:')
        '10'
        >>> find_matching(['first line:10', 'second_line:20'], 'second line')
        Traceback (most recent call last):
          ...
        ValueError: Test aborted
        >>> find_matching('first line:10\', 'second_line:20'], 'second_line:')
        '20'
        >>> find_matching('first line:10\', 'second_line:20\nthird_line:30'],
                          'third_line:')
        '30'
        """
        __tracebackhide__ = True
        for line in '\n'.join(text).splitlines():
            pos = line.find(match)
            if pos != -1:
                return line[:pos] + line[pos + len(match):]

        pytest.fail("Expected '%s' but not found in output")

    def check_equal(expected_fname, actual_fname, failure_msg):
        """Check that a file matches its expected contents

        Args:
            expected_fname: Filename containing expected contents
            actual_fname: Filename containing actual contents
            failure_msg: Message to print on failure
        """
        expected_data = read_file(expected_fname)
        actual_data = read_file(actual_fname)
        assert expected_data == actual_data, failure_msg

    def check_not_equal(expected_fname, actual_fname, failure_msg):
        """Check that a file does not match its expected contents

        Args:
            expected_fname: Filename containing expected contents
            actual_fname: Filename containing actual contents
            failure_msg: Message to print on failure
        """
        expected_data = read_file(expected_fname)
        actual_data = read_file(actual_fname)
        assert expected_data != actual_data, failure_msg

    def run_fit_test(mkimage):
        """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
        """
        # Set up invariant files
        control_dtb = make_dtb()
        kernel = make_kernel('test-kernel.bin', 'kernel')
        ramdisk = make_ramdisk('test-ramdisk.bin', 'ramdisk')
        loadables1 = make_kernel('test-loadables1.bin', 'lenrek')
        loadables2 = make_ramdisk('test-loadables2.bin', 'ksidmar')
        kernel_out = make_fname('kernel-out.bin')
        fdt_out = make_fname('fdt-out.dtb')
        ramdisk_out = make_fname('ramdisk-out.bin')
        loadables1_out = make_fname('loadables1-out.bin')
        loadables2_out = make_fname('loadables2-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' : '',

            'loadables1' : loadables1,
            'loadables1_out' : loadables1_out,
            'loadables1_addr' : 0x100000,
            'loadables1_size' : filesize(loadables1),
            'loadables1_load' : '',

            'loadables2' : loadables2,
            'loadables2_out' : loadables2_out,
            'loadables2_addr' : 0x140000,
            'loadables2_size' : filesize(loadables2),
            'loadables2_load' : '',

            'loadables_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
        cons.config.dtb = control_dtb
        cons.restart_uboot()
        with cons.log.section('Kernel load'):
            output = cons.run_command_list(cmd.splitlines())
            check_equal(kernel, kernel_out, 'Kernel not loaded')
            check_not_equal(control_dtb, fdt_out,
                            'FDT loaded but should be ignored')
            check_not_equal(ramdisk, ramdisk_out,
                            'Ramdisk loaded but should not be')

            # Find out the offset in the FIT where U-Boot has found the FDT
            line = find_matching(output, '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)
            assert fit_offset == real_fit_offset, (
                  'U-Boot loaded FDT from offset %#x, FDT is actually at %#x' %
                  (fit_offset, real_fit_offset))

        # Now a kernel and an FDT
        with cons.log.section('Kernel + FDT load'):
            params['fdt_load'] = 'load = <%#x>;' % params['fdt_addr']
            fit = make_fit(mkimage, params)
            cons.restart_uboot()
            output = cons.run_command_list(cmd.splitlines())
            check_equal(kernel, kernel_out, 'Kernel not loaded')
            check_equal(control_dtb, fdt_out, 'FDT not loaded')
            check_not_equal(ramdisk, ramdisk_out,
                            'Ramdisk loaded but should not be')

        # Try a ramdisk
        with cons.log.section('Kernel + FDT + Ramdisk load'):
            params['ramdisk_config'] = 'ramdisk = "ramdisk@1";'
            params['ramdisk_load'] = 'load = <%#x>;' % params['ramdisk_addr']
            fit = make_fit(mkimage, params)
            cons.restart_uboot()
            output = cons.run_command_list(cmd.splitlines())
            check_equal(ramdisk, ramdisk_out, 'Ramdisk not loaded')

        # Configuration with some Loadables
        with cons.log.section('Kernel + FDT + Ramdisk load + Loadables'):
            params['loadables_config'] = 'loadables = "kernel@2", "ramdisk@2";'
            params['loadables1_load'] = ('load = <%#x>;' %
                                         params['loadables1_addr'])
            params['loadables2_load'] = ('load = <%#x>;' %
                                         params['loadables2_addr'])
            fit = make_fit(mkimage, params)
            cons.restart_uboot()
            output = cons.run_command_list(cmd.splitlines())
            check_equal(loadables1, loadables1_out,
                        'Loadables1 (kernel) not loaded')
            check_equal(loadables2, loadables2_out,
                        'Loadables2 (ramdisk) not loaded')

    cons = u_boot_console
    try:
        # We need to use our own device tree file. Remember to restore it
        # afterwards.
        old_dtb = cons.config.dtb
        mkimage = cons.config.build_dir + '/tools/mkimage'
        run_fit_test(mkimage)
    finally:
        # Go back to the original U-Boot with the correct dtb.
        cons.config.dtb = old_dtb
        cons.restart_uboot()