kernel: Use the debian infrastructure to construct kernel config files

src/scripts/build_kernel.sh

 #! /bin/sh
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script contains the set of commands to build a kernel package.
 #
 # If successful, a new linux-image-*.deb file will appear in the specified
 # output directory.
 #
 # The user-provided kernel config file is parsed to obtain information about
 # the desired kernel version and target platform. Here are the requirements:
 # 1) Kernel version string in the header, e.g. "Linux kernel version: 2.6.30"
 # 2) Target architecture variables set up, e.g. CONFIG_X86, CONFIG_ARM, etc.
 # 3) LOCALVERSION set to describe target platform (e.g. intel-menlow). This is
 #    used for package naming.
 SRC_ROOT=$(dirname $(readlink -f $(dirname "$0")))
 . "${SRC_ROOT}/third_party/shflags/files/src/shflags"
 
 KERNEL_DIR="$SRC_ROOT/third_party/kernel"
-DEFAULT_KCONFIG="${KERNEL_DIR}/files/chromeos/config/chromeos-intel-menlow"
+DEFAULT_KFLAVOUR="chromeos-intel-menlow"
 
 # Flags
 DEFAULT_BUILD_ROOT=${BUILD_ROOT:-"${SRC_ROOT}/build"}
-DEFINE_string config "${DEFAULT_KCONFIG}"                              \
-  "The kernel configuration file to use."
+DEFINE_string flavour "${DEFAULT_KFLAVOUR}"                              \
+  "The kernel flavour to use."
 DEFINE_integer revision 002                                            \
   "The package revision to use"
 DEFINE_string output_root "${DEFAULT_BUILD_ROOT}/x86/local_packages"   \
   "Directory in which to place the resulting .deb package"
 DEFINE_string build_root "$DEFAULT_BUILD_ROOT"                         \
   "Root of build output"
 FLAGS_HELP="Usage: $0 [flags]"
 
 # Parse command line
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
 # Die on any errors.
 set -e
 
 # TODO: We detect the ARCH below. We can sed the FLAGS_output_root to replace
 # an ARCH placeholder with the proper architecture rather than assuming x86.
 mkdir -p "$FLAGS_output_root"
 
 # Get kernel package configuration from repo.
 # TODO: Find a workaround for needing sudo for this. Maybe create a symlink
 # to /tmp/kernel-pkg.conf when setting up the chroot env?
 sudo cp "$KERNEL_DIR"/package/kernel-pkg.conf /etc/kernel-pkg.conf
 
+#
+# Generate the flavour config file.
+#
+flavour=$FLAGS_flavour
+(cd ${KERNEL_DIR}/files; debian/rules prepare-${flavour})
+
 # Parse kernel config file for target architecture information. This is needed
 # to determine the full package name and also to setup the environment for
 # kernel build scripts which use "uname -m" to autodetect architecture.
-KCONFIG="$FLAGS_config"
+KCONFIG="${KERNEL_DIR}/files/debian/build/build-${flavour}/.config"
 if [ ! -f "$KCONFIG" ]; then
-    KCONFIG="$KERNEL_DIR"/files/chromeos/config/"$KCONFIG"
+    echo Major bummer. Could not find kernel config.
+    exit 1
 fi
 if [ -n $(grep 'CONFIG_X86=y' "$KCONFIG") ]
 then
     ARCH="i386"
 elif [ -n $(grep 'CONFIG_X86_64=y' "$KCONFIG") ]
 then
     ARCH="x86_64"
 elif [ -n $(grep 'CONFIG_ARM=y' "$KCONFIG") ]
 then
     ARCH="arm"
@@ skipping 75 matching lines @@
 
 # make-kpkg dumps the newly created package in the parent directory
 if [ -e "../${PACKAGE}" ]
 then
     mv "../${PACKAGE}" "${FLAGS_output_root}"
     echo "Kernel build successful, check ${FLAGS_output_root}/${PACKAGE}"
 else
     echo "Kernel build failed"
     exit 1
 fi