[dpdk-dev] scripts: add script for generating customised build config

diff --git a/scripts/dpdk_config.py b/scripts/dpdk_config.py
new file mode 100755
index 0000000..01236d8
--- /dev/null
+++ b/scripts/dpdk_config.py
@@ -0,0 +1,198 @@ 
+#! /usr/bin/env python
+#
+#   BSD LICENSE
+#
+#   Copyright(c) 2016 Intel Corporation. All rights reserved.
+#   All rights reserved.
+#
+#   Redistribution and use in source and binary forms, with or without
+#   modification, are permitted provided that the following conditions
+#   are met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+#     * Neither the name of Intel Corporation nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+#   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+#   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+#   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+#   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+#   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+#   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+#   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+#   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+#   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+#   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+from __future__ import print_function
+import sys
+import os.path
+import getopt
+import subprocess
+
+out = "build"
+base = None
+machine = None
+
+
+def print_usage(cmd, f):
+    print("""Usage: %s -b <base_config> [-o <output_dir>] [options...] """
+          % os.path.basename(cmd), file=f)
+
+
+def print_help(cmd):
+    print_usage(cmd, sys.stdout)
+    print("""
+Generates a new DPDK build time configuration in the given output directory,
+using as a starting point the provided base configuration. Once completed
+successfully, DPDK can then be built using that configuration by running the
+command "make -C <output_dir>".
+
+-b, --base-config=CONFIG
+    Use the configuration given by CONFIG as the starting point for the
+    build configuration. CONFIG must be a valid DPDK default configuration
+    provided by a file "defconfig_CONFIG" in the top level "config"
+    directory.
+    Example: "-b x86_64-native-linuxapp-gcc"
+
+-o, --output-dir=DIR
+    Use DIR as the resulting output directory. If unspecified the default
+    value of "build" is used.
+
+-m, --machine-type=TYPE
+    Override the machine-type value given in the default configuration by
+    setting it to TYPE. Using regular options, regular y/n values can be
+    changed, but not string options, so this explicit override for machine
+    type exists to allow changing it.
+
+-h, --help
+    Print this help text and then exit
+
+Other options passed after these on the commandline should be in the format of
+"name=y|n" and are overrides to be applied to the configuration to toggle the
+y|n settings in the file.
+
+Matches are applied on partial values, so for example "DEBUG=y" will turn on
+all options ending in "DEBUG". This means that a full option need not always be
+specified, for example, "CONFIG_RTE_LIBRTE_" prefixes can generally be omitted.
+
+Examples:
+
+To generate a configuration for DPDK
+- based off x86_64-native-linuxapp-gcc,
+- changing the machine type to "default",
+- turning on the pcap PMD,
+- disabling the KNI and igb_uio kernel modules, and
+- placing the output in a suitably named folder
+use:
+
+    %s -o x86_64-default-linuxapp-gcc -b x86_64-native-linuxapp-gcc \\
+        -m default PMD_PCAP=y IGB_UIO=n KNI_KMOD=n
+
+""" % os.path.basename(cmd))
+
+
+def parse_opts(argv):
+    global out, base, machine
+    long_opts = ["output-dir", "base-config", "machine-type", "help"]
+    try:
+        opts, args = getopt.getopt(argv[1:], "o:b:m:h", long_opts)
+    except getopt.GetoptError as err:
+        print(str(err))
+        print_usage(argv[0], sys.stderr)
+        sys.exit(1)
+
+    for o, a in opts:
+        if o in ["-o", "--output-dir"]:
+            out = a
+        elif o in ["-b", "--base-config"]:
+            base = a
+        elif o in ["-m", "--machine-type"]:
+            machine = a
+        elif o in ["-h", "--help"]:
+            print_help(argv[0])
+            sys.exit()
+        else:
+            print("Error: Unhandled option '%s'\n" % o,
+                  file=sys.stderr)
+            sys.exit(1)
+
+    if base is None:
+        print_usage(argv[0], sys.stderr)
+        sys.exit(1)
+    if not os.path.exists("config/defconfig_%s" % base):
+        print("Error, invalid base configuration specified: %s" % base)
+        sys.exit(1)
+
+    enable_args = [a[:-2] for a in args if a[-2:] == "=y"]
+    disable_args = [a[:-2] for a in args if a[-2:] == "=n"]
+    invalid = [a for a in args if a[-2:] not in ("=y", "=n")]
+    if len(invalid) > 0:
+        print("Error, options not ending in '=y' or '=n': %s"
+              % str(invalid))
+        sys.exit(1)
+    return (enable_args, disable_args)
+
+
+def run_make_config():
+    try:
+        # the flush parameter is not always implemented so provide fallback
+        print("Running 'make config'...", end=' ', flush=True)
+    except Exception:
+        print("Running 'make config'...")
+
+    cmd = "make config T=%s O=%s" % (base, out)
+    if sys.platform.startswith("freebsd"):
+        cmd = cmd.replace("make", "gmake", 1)
+    if subprocess.call(cmd.split()) != 0:
+        print("make config called failed")
+        sys.exit(1)
+
+
+def load_file(fn):
+    fd = open(fn)
+    contents = [line.strip() for line in fd.readlines()]
+    fd.close()
+    return contents
+
+
+def write_file(fn, config):
+    fd = open(fn, "w")
+    fd.writelines(["%s\n" % line for line in config])
+    fd.close()
+
+
+def change_settings(enable, disable):
+    config = load_file("%s/.config" % out)
+    print("Enabling settings %s" % str(enable))
+    for entry in enable:
+        config = [line.replace("%s=n" % entry, "%s=y" % entry)
+                  for line in config]
+    print("Disabling settings %s" % str(disable))
+    for entry in disable:
+        config = [line.replace("%s=y" % entry, "%s=n" % entry)
+                  for line in config]
+
+    if machine is not None:
+        print("Setting machine to '%s'" % machine)
+        config.append("CONFIG_RTE_MACHINE=\"%s\"" % machine)
+    write_file("%s/.config" % out, config)
+
+
+def main():
+    enable, disable = parse_opts(sys.argv)
+    run_make_config()
+    change_settings(enable, disable)
+    print("Done")
+
+
+if __name__ == "__main__":
+    main()