diff --git a/tools/buildman/README b/tools/buildman/README
index c67a074cb5..0666bc7d56 100644
--- a/tools/buildman/README
+++ b/tools/buildman/README
@@ -128,10 +128,10 @@ Selecting which boards to build
 ===============================
 
 Buildman lets you build all boards, or a subset. Specify the subset by passing
-command-line arguments that list the desired board name, architecture name,
-SOC name, or anything else in the boards.cfg file. Multiple arguments are
-allowed. Each argument will be interpreted as a regular expression, so
-behaviour is a superset of exact or substring matching. Examples are:
+command-line arguments that list the desired build target, architecture,
+CPU, board name, vendor, SoC or options. Multiple arguments are allowed. Each
+argument will be interpreted as a regular expression, so behaviour is a superset
+of exact or substring matching. Examples are:
 
 * 'tegra20'      All boards with a Tegra20 SoC
 * 'tegra'        All boards with any Tegra Soc (Tegra20, Tegra30, Tegra114...)
@@ -1054,7 +1054,6 @@ between one commit and the next.
 For example:
 
 $ buildman -b squash brppt1 -sU
-boards.cfg is up to date. Nothing to do.
 Summary of 2 commits for 3 boards (3 threads, 3 jobs per thread)
 01: Migrate bootlimit to Kconfig
 02: Squashed commit of the following:
@@ -1309,6 +1308,18 @@ Some options you might like are:
         break anything. But note this does not check bisectability!
 
 
+Using boards.cfg
+================
+
+This file is no-longer needed by buildman but it is still generated in the
+working directory. This helps avoid a delay on every build, since scanning all
+the Kconfig files takes a few seconds. Use the -R flag to force regeneration
+of the file - in that case buildman exits after writing the file.
+
+You should use 'buildman -nv <criteria>' instead of greoing the boards.cfg file,
+since it may be dropped altogether in future.
+
+
 TODO
 ====
 
diff --git a/tools/buildman/boards.py b/tools/buildman/boards.py
index ec143f9e0f..c18914253e 100644
--- a/tools/buildman/boards.py
+++ b/tools/buildman/boards.py
@@ -1,12 +1,93 @@
 # SPDX-License-Identifier: GPL-2.0+
 # Copyright (c) 2012 The Chromium OS Authors.
+# Author: Simon Glass <sjg@chromium.org>
+# Author: Masahiro Yamada <yamada.m@jp.panasonic.com>
 
 """Maintains a list of boards and allows them to be selected"""
 
 from collections import OrderedDict
+import errno
+import fnmatch
+import glob
+import multiprocessing
+import os
 import re
+import sys
+import tempfile
+import time
 
 from buildman import board
+from buildman import kconfiglib
+
+
+### constant variables ###
+OUTPUT_FILE = 'boards.cfg'
+CONFIG_DIR = 'configs'
+SLEEP_TIME = 0.03
+COMMENT_BLOCK = '''#
+# List of boards
+#   Automatically generated by %s: don't edit
+#
+# Status, Arch, CPU, SoC, Vendor, Board, Target, Options, Maintainers
+
+''' % __file__
+
+
+def try_remove(f):
+    """Remove a file ignoring 'No such file or directory' error."""
+    try:
+        os.remove(f)
+    except OSError as exception:
+        # Ignore 'No such file or directory' error
+        if exception.errno != errno.ENOENT:
+            raise
+
+
+def output_is_new(output):
+    """Check if the output file is up to date.
+
+    Returns:
+      True if the given output file exists and is newer than any of
+      *_defconfig, MAINTAINERS and Kconfig*.  False otherwise.
+    """
+    try:
+        ctime = os.path.getctime(output)
+    except OSError as exception:
+        if exception.errno == errno.ENOENT:
+            # return False on 'No such file or directory' error
+            return False
+        else:
+            raise
+
+    for (dirpath, dirnames, filenames) in os.walk(CONFIG_DIR):
+        for filename in fnmatch.filter(filenames, '*_defconfig'):
+            if fnmatch.fnmatch(filename, '.*'):
+                continue
+            filepath = os.path.join(dirpath, filename)
+            if ctime < os.path.getctime(filepath):
+                return False
+
+    for (dirpath, dirnames, filenames) in os.walk('.'):
+        for filename in filenames:
+            if (fnmatch.fnmatch(filename, '*~') or
+                not fnmatch.fnmatch(filename, 'Kconfig*') and
+                not filename == 'MAINTAINERS'):
+                continue
+            filepath = os.path.join(dirpath, filename)
+            if ctime < os.path.getctime(filepath):
+                return False
+
+    # Detect a board that has been removed since the current board database
+    # was generated
+    with open(output, encoding="utf-8") as f:
+        for line in f:
+            if line[0] == '#' or line == '\n':
+                continue
+            defconfig = line.split()[6] + '_defconfig'
+            if not os.path.exists(os.path.join(CONFIG_DIR, defconfig)):
+                return False
+
+    return True
 
 
 class Expr:
@@ -76,6 +157,190 @@ class Term:
         return True
 
 
+class KconfigScanner:
+
+    """Kconfig scanner."""
+
+    ### constant variable only used in this class ###
+    _SYMBOL_TABLE = {
+        'arch' : 'SYS_ARCH',
+        'cpu' : 'SYS_CPU',
+        'soc' : 'SYS_SOC',
+        'vendor' : 'SYS_VENDOR',
+        'board' : 'SYS_BOARD',
+        'config' : 'SYS_CONFIG_NAME',
+        'options' : 'SYS_EXTRA_OPTIONS'
+    }
+
+    def __init__(self):
+        """Scan all the Kconfig files and create a Kconfig object."""
+        # Define environment variables referenced from Kconfig
+        os.environ['srctree'] = os.getcwd()
+        os.environ['UBOOTVERSION'] = 'dummy'
+        os.environ['KCONFIG_OBJDIR'] = ''
+        self._conf = kconfiglib.Kconfig(warn=False)
+
+    def __del__(self):
+        """Delete a leftover temporary file before exit.
+
+        The scan() method of this class creates a temporay file and deletes
+        it on success.  If scan() method throws an exception on the way,
+        the temporary file might be left over.  In that case, it should be
+        deleted in this destructor.
+        """
+        if hasattr(self, '_tmpfile') and self._tmpfile:
+            try_remove(self._tmpfile)
+
+    def scan(self, defconfig):
+        """Load a defconfig file to obtain board parameters.
+
+        Arguments:
+          defconfig: path to the defconfig file to be processed
+
+        Returns:
+          A dictionary of board parameters.  It has a form of:
+          {
+              'arch': <arch_name>,
+              'cpu': <cpu_name>,
+              'soc': <soc_name>,
+              'vendor': <vendor_name>,
+              'board': <board_name>,
+              'target': <target_name>,
+              'config': <config_header_name>,
+              'options': <extra_options>
+          }
+        """
+        # strip special prefixes and save it in a temporary file
+        fd, self._tmpfile = tempfile.mkstemp()
+        with os.fdopen(fd, 'w') as f:
+            for line in open(defconfig):
+                colon = line.find(':CONFIG_')
+                if colon == -1:
+                    f.write(line)
+                else:
+                    f.write(line[colon + 1:])
+
+        self._conf.load_config(self._tmpfile)
+        try_remove(self._tmpfile)
+        self._tmpfile = None
+
+        params = {}
+
+        # Get the value of CONFIG_SYS_ARCH, CONFIG_SYS_CPU, ... etc.
+        # Set '-' if the value is empty.
+        for key, symbol in list(self._SYMBOL_TABLE.items()):
+            value = self._conf.syms.get(symbol).str_value
+            if value:
+                params[key] = value
+            else:
+                params[key] = '-'
+
+        defconfig = os.path.basename(defconfig)
+        params['target'], match, rear = defconfig.partition('_defconfig')
+        assert match and not rear, '%s : invalid defconfig' % defconfig
+
+        # fix-up for aarch64
+        if params['arch'] == 'arm' and params['cpu'] == 'armv8':
+            params['arch'] = 'aarch64'
+
+        # fix-up options field. It should have the form:
+        # <config name>[:comma separated config options]
+        if params['options'] != '-':
+            params['options'] = params['config'] + ':' + \
+                                params['options'].replace(r'\"', '"')
+        elif params['config'] != params['target']:
+            params['options'] = params['config']
+
+        return params
+
+
+class MaintainersDatabase:
+
+    """The database of board status and maintainers."""
+
+    def __init__(self):
+        """Create an empty database."""
+        self.database = {}
+
+    def get_status(self, target):
+        """Return the status of the given board.
+
+        The board status is generally either 'Active' or 'Orphan'.
+        Display a warning message and return '-' if status information
+        is not found.
+
+        Returns:
+          'Active', 'Orphan' or '-'.
+        """
+        if not target in self.database:
+            print("WARNING: no status info for '%s'" % target, file=sys.stderr)
+            return '-'
+
+        tmp = self.database[target][0]
+        if tmp.startswith('Maintained'):
+            return 'Active'
+        elif tmp.startswith('Supported'):
+            return 'Active'
+        elif tmp.startswith('Orphan'):
+            return 'Orphan'
+        else:
+            print(("WARNING: %s: unknown status for '%s'" %
+                                  (tmp, target)), file=sys.stderr)
+            return '-'
+
+    def get_maintainers(self, target):
+        """Return the maintainers of the given board.
+
+        Returns:
+          Maintainers of the board.  If the board has two or more maintainers,
+          they are separated with colons.
+        """
+        if not target in self.database:
+            print("WARNING: no maintainers for '%s'" % target, file=sys.stderr)
+            return ''
+
+        return ':'.join(self.database[target][1])
+
+    def parse_file(self, file):
+        """Parse a MAINTAINERS file.
+
+        Parse a MAINTAINERS file and accumulates board status and
+        maintainers information.
+
+        Arguments:
+          file: MAINTAINERS file to be parsed
+        """
+        targets = []
+        maintainers = []
+        status = '-'
+        for line in open(file, encoding="utf-8"):
+            # Check also commented maintainers
+            if line[:3] == '#M:':
+                line = line[1:]
+            tag, rest = line[:2], line[2:].strip()
+            if tag == 'M:':
+                maintainers.append(rest)
+            elif tag == 'F:':
+                # expand wildcard and filter by 'configs/*_defconfig'
+                for f in glob.glob(rest):
+                    front, match, rear = f.partition('configs/')
+                    if not front and match:
+                        front, match, rear = rear.rpartition('_defconfig')
+                        if match and not rear:
+                            targets.append(front)
+            elif tag == 'S:':
+                status = rest
+            elif line == '\n':
+                for target in targets:
+                    self.database[target] = (status, maintainers)
+                targets = []
+                maintainers = []
+                status = '-'
+        if targets:
+            for target in targets:
+                self.database[target] = (status, maintainers)
+
+
 class Boards:
     """Manage a list of boards."""
     def __init__(self):
@@ -288,3 +553,140 @@ class Boards:
                 warnings.append(f"Boards not found: {', '.join(remaining)}\n")
 
         return result, warnings
+
+    def scan_defconfigs_for_multiprocess(self, queue, defconfigs):
+        """Scan defconfig files and queue their board parameters
+
+        This function is intended to be passed to
+        multiprocessing.Process() constructor.
+
+        Arguments:
+        queue: An instance of multiprocessing.Queue().
+                The resulting board parameters are written into it.
+        defconfigs: A sequence of defconfig files to be scanned.
+        """
+        kconf_scanner = KconfigScanner()
+        for defconfig in defconfigs:
+            queue.put(kconf_scanner.scan(defconfig))
+
+    def read_queues(self, queues, params_list):
+        """Read the queues and append the data to the paramers list"""
+        for q in queues:
+            while not q.empty():
+                params_list.append(q.get())
+
+    def scan_defconfigs(self, jobs=1):
+        """Collect board parameters for all defconfig files.
+
+        This function invokes multiple processes for faster processing.
+
+        Arguments:
+        jobs: The number of jobs to run simultaneously
+        """
+        all_defconfigs = []
+        for (dirpath, dirnames, filenames) in os.walk(CONFIG_DIR):
+            for filename in fnmatch.filter(filenames, '*_defconfig'):
+                if fnmatch.fnmatch(filename, '.*'):
+                    continue
+                all_defconfigs.append(os.path.join(dirpath, filename))
+
+        total_boards = len(all_defconfigs)
+        processes = []
+        queues = []
+        for i in range(jobs):
+            defconfigs = all_defconfigs[total_boards * i // jobs :
+                                        total_boards * (i + 1) // jobs]
+            q = multiprocessing.Queue(maxsize=-1)
+            p = multiprocessing.Process(
+                target=self.scan_defconfigs_for_multiprocess,
+                args=(q, defconfigs))
+            p.start()
+            processes.append(p)
+            queues.append(q)
+
+        # The resulting data should be accumulated to this list
+        params_list = []
+
+        # Data in the queues should be retrieved preriodically.
+        # Otherwise, the queues would become full and subprocesses would get stuck.
+        while any([p.is_alive() for p in processes]):
+            self.read_queues(queues, params_list)
+            # sleep for a while until the queues are filled
+            time.sleep(SLEEP_TIME)
+
+        # Joining subprocesses just in case
+        # (All subprocesses should already have been finished)
+        for p in processes:
+            p.join()
+
+        # retrieve leftover data
+        self.read_queues(queues, params_list)
+
+        return params_list
+
+    def insert_maintainers_info(self, params_list):
+        """Add Status and Maintainers information to the board parameters list.
+
+        Arguments:
+        params_list: A list of the board parameters
+        """
+        database = MaintainersDatabase()
+        for (dirpath, dirnames, filenames) in os.walk('.'):
+            if 'MAINTAINERS' in filenames:
+                database.parse_file(os.path.join(dirpath, 'MAINTAINERS'))
+
+        for i, params in enumerate(params_list):
+            target = params['target']
+            params['status'] = database.get_status(target)
+            params['maintainers'] = database.get_maintainers(target)
+            params_list[i] = params
+
+    def format_and_output(self, params_list, output):
+        """Write board parameters into a file.
+
+        Columnate the board parameters, sort lines alphabetically,
+        and then write them to a file.
+
+        Arguments:
+        params_list: The list of board parameters
+        output: The path to the output file
+        """
+        FIELDS = ('status', 'arch', 'cpu', 'soc', 'vendor', 'board', 'target',
+                'options', 'maintainers')
+
+        # First, decide the width of each column
+        max_length = dict([ (f, 0) for f in FIELDS])
+        for params in params_list:
+            for f in FIELDS:
+                max_length[f] = max(max_length[f], len(params[f]))
+
+        output_lines = []
+        for params in params_list:
+            line = ''
+            for f in FIELDS:
+                # insert two spaces between fields like column -t would
+                line += '  ' + params[f].ljust(max_length[f])
+            output_lines.append(line.strip())
+
+        # ignore case when sorting
+        output_lines.sort(key=str.lower)
+
+        with open(output, 'w', encoding="utf-8") as f:
+            f.write(COMMENT_BLOCK + '\n'.join(output_lines) + '\n')
+
+    def ensure_board_list(self, output, jobs=1, force=False, quiet=False):
+        """Generate a board database file if needed.
+
+        Arguments:
+        output: The name of the output file
+        jobs: The number of jobs to run simultaneously
+        force: Force to generate the output even if it is new
+        quiet: True to avoid printing a message if nothing needs doing
+        """
+        if not force and output_is_new(output):
+            if not quiet:
+                print("%s is up to date. Nothing to do." % output)
+            return
+        params_list = self.scan_defconfigs(jobs)
+        self.insert_maintainers_info(params_list)
+        self.format_and_output(params_list, output)
diff --git a/tools/buildman/cmdline.py b/tools/buildman/cmdline.py
index cef2068c98..b29c1eb5ee 100644
--- a/tools/buildman/cmdline.py
+++ b/tools/buildman/cmdline.py
@@ -89,6 +89,8 @@ def ParseArgs():
           default=False, help="Use full toolchain path in CROSS_COMPILE")
     parser.add_option('-P', '--per-board-out-dir', action='store_true',
           default=False, help="Use an O= (output) directory per board rather than per thread")
+    parser.add_option('-R', '--regen-board-list', action='store_true',
+          help='Force regeneration of the list of boards, like the old boards.cfg file')
     parser.add_option('-s', '--summary', action='store_true',
           default=False, help='Show a build summary')
     parser.add_option('-S', '--show-sizes', action='store_true',
diff --git a/tools/buildman/control.py b/tools/buildman/control.py
index 8d3e781d51..79ce2f6978 100644
--- a/tools/buildman/control.py
+++ b/tools/buildman/control.py
@@ -186,18 +186,14 @@ def DoBuildman(options, args, toolchains=None, make_func=None, brds=None,
         if not os.path.exists(options.output_dir):
             os.makedirs(options.output_dir)
         board_file = os.path.join(options.output_dir, 'boards.cfg')
-        our_path = os.path.dirname(os.path.realpath(__file__))
-        genboardscfg = os.path.join(our_path, '../genboardscfg.py')
-        if not os.path.exists(genboardscfg):
-            genboardscfg = os.path.join(options.git, 'tools/genboardscfg.py')
-        status = subprocess.call([genboardscfg, '-q', '-o', board_file])
-        if status != 0:
-            # Older versions don't support -q
-            status = subprocess.call([genboardscfg, '-o', board_file])
-            if status != 0:
-                sys.exit("Failed to generate boards.cfg")
 
         brds = boards.Boards()
+        brds.ensure_board_list(board_file,
+                               options.threads or multiprocessing.cpu_count(),
+                               force=options.regen_board_list,
+                               quiet=not options.verbose)
+        if options.regen_board_list:
+            return 0
         brds.read_boards(board_file)
 
     exclude = []