#!/bin/bash

# Create packages for the kernel(s) used on a specific platform.
# Inspiration taken from Slackware and ARMedslack.
# Written by Eric Hameleers <alien@slackware.com>, Eindhoven, The Netherlands


PLATFORM=${1:-tegra}
KVER=${KVER:-3.8.4}
BUILD=${BUILD:-1}


case "$PLATFORM" in
  generic*|huge*)
    ARCH=${ARCH:-x86_64}
    KARCH=${ARCH}
    HEADERS_ARCH=${x86}
    MODULES=${MODULES:-ext4}
    ;;
  tegra|beagleboard|exynos5)
    ARCH=${ARCH:-armv7hl}
    KARCH=arm
    HEADERS_ARCH=arm
    MODULES=${MODULES:-ext4}
    ;;
  *)
    ARCH=${ARCH:-arm}
    KARCH=arm
    HEADERS_ARCH=arm
    MODULES=${MODULES:-ext4}
    ;;
esac


KCONF=${KCONF:-oldconfig}
CWD=$(pwd)
TMP=${TMP:-/tmp}
TMPBUILD=$TMP/tmpbuild-$KVER-$PLATFORM
NUMJOBS=7

OUTPUT=/tmp/$ARCH
rm -rf $OUTPUT
mkdir -p $OUTPUT


# Only meant for the "prep" stage which can be run by a non-root user:
if [ $(/bin/id -u) -eq 0 ]; then
  SRC="/usr/src"
else
  SRC=$TMP
  mkdir -p $SRC
fi


# Determine patch level required & apply the patch (taken from armedslack):
function auto_apply_patch () {
  patchfile=$1

  # Decompress the patch if it's compressed with a known method:
  FTYPE=$( file $patchfile )
  case "$FTYPE" in
   *xz*compressed*)
     xz -dc $patchfile > $TMP/$(basename $patchfile).unpacked
     patchfile=$TMP/$(basename $patchfile).unpacked ;;
   *bzip2*compressed*)
     bzcat -f $patchfile > $TMP/$(basename $patchfile).unpacked
     patchfile=$TMP/$(basename $patchfile).unpacked ;;
   *gzip*compressed*)
     zcat -f $patchfile > $TMP/$(basename $patchfile).unpacked
     patchfile=$TMP/$(basename $patchfile).unpacked ;;
  esac

  # By now the patch is decompressed or wasn't compressed originally.

  # Most patches should not require more levels than this:
  success=0
  for (( pl=0 ; pl<=5 ; pl++ )) ; do
    echo "Patch : $patchfile , trying patch level $pl"
    patch -N --fuzz=20 -t --dry-run -p$pl < $patchfile > /dev/null 2>&1 && success=1 && break
  done
  if [ $success = 1 ]; then
    echo "Patch: $patchfile will apply at level $pl"
    patch -N --fuzz=20 --verbose --backup --suffix=.orig -p$pl < $patchfile
    return 0
  else
    echo "Patch: $patchfile failed to apply at levels 0-5"
    return 1
  fi
}


patch_kernel() {
  if [ -d $CWD/sources/patches/$PLATFORM/$KVER ]; then
    PATCHDIR=$CWD/sources/patches/$PLATFORM/$KVER
  elif [ -d $CWD/sources/patches/$PLATFORM ]; then
    PATCHDIR=$CWD/sources/patches/$PLATFORM
  elif [ -d $CWD/sources/patches/generic ]; then
    PATCHDIR=$CWD/sources/patches/generic
  else
    return 0
  fi
  ( cd $SRC/linux-${KVER}
    for PATCHFILE in $(find $PATCHDIR -type f); do
      auto_apply_patch $PATCHFILE || exit 1
    done
  ) || exit 1
}


echo "Extracting kernel source to $SRC/linux-${KVER} ..."
# This will delete your current source tree for this kernel!
rm -rf $SRC/linux-${KVER}
( cd $SRC
  for EXT in xz bz2 ; do
    if [ -f $CWD/sources/kernel/$PLATFORM/linux-${KVER}.tar.$EXT ]; then
      tar xf $CWD/sources/kernel/$PLATFORM/linux-${KVER}.tar.$EXT
      continue
    elif [ -f $CWD/sources/kernel/linux-${KVER}.tar.$EXT ]; then
      tar xf $CWD/sources/kernel/linux-${KVER}.tar.$EXT
      continue
    fi
  done
  if [ ! $? = 0 ]; then
    echo "FATAL: Error unpacking the kernel archive... aborting."
    exit 1
  elif [ ! -d linux-${KVER} ]; then
    echo "FATAL: Kernel directory was not found... aborting."
    exit 1
  else
    cd linux-${KVER}

    # Apply patches to the kernel source:
    patch_kernel || exit 1

    # Add firmware files:
    find $CWD/sources/firmware/$PLATFORM -type f \
      -exec tar -C $SRC/linux-${KVER}/firmware -xvf {} \;

    case "$PLATFORM" in
    tegra)
      # Build fix for compiling Tegra USB support as modules:
      sed -i '/obj-$(CONFIG_USB_COMMON).*+= phy\// a\obj-$(CONFIG_USB_EHCI_TEGRA)   += phy\/' drivers/usb/Makefile || exit 1
      ;;
    esac

    chown -R root:root .
    echo "Fixing permissions... takes a long time in a VM or on ARM..."
    find . -perm 666 -exec chmod 644 {} \;
    find . -perm 664 -exec chmod 644 {} \;
    find . -perm 600 -exec chmod 644 {} \;
    find . -perm 444 -exec chmod 644 {} \;
    find . -perm 400 -exec chmod 644 {} \;
    find . -perm 440 -exec chmod 644 {} \;
    find . -perm 777 -exec chmod 755 {} \;
    find . -perm 775 -exec chmod 755 {} \;
    find . -perm 511 -exec chmod 755 {} \;
    find . -perm 711 -exec chmod 755 {} \;
    find . -perm 555 -exec chmod 755 {} \;
  fi
)


# Patched kernel source is ready to configure now:
if [ -f $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER} ]; then
  if ! grep -q "CONFIG_LOCALVERSION=\"-$PLATFORM\"" $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER} ; then
    echo "*******************************************************************"
    echo "WARNING:"
    echo "CONFIG_LOCALVERSION not set to '-$PLATFORM'"
    echo "in $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER}"
    echo "Are you certain you want to continue? Else press Ctrl-C now!"
    echo "*******************************************************************"
    read JUNK
  fi

  echo "Using $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER} ..."
  install -m0644 $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER} \
     $SRC/linux-${KVER}/.config
fi

# Add our patches to the kernel source directory:
unset PATCHDIR
if [ -d $CWD/sources/patches/$PLATFORM/$KVER ]; then
  PATCHDIR=$CWD/sources/patches/$PLATFORM/$KVER
elif [ -d $CWD/sources/patches/$KVER ]; then
  PATCHDIR=$CWD/sources/patches/$KVER
elif [ -d $CWD/sources/patches/generic ]; then
  PATCHDIR=$CWD/sources/patches/generic
fi
if [ -n "$PATCHDIR" ]; then
  for file in $(find $PATCHDIR -type f) ; do
    install -m0644 $file $SRC/linux-${KVER}/$(basename $file)
  done
fi

# End of preparations
if echo "$*" | grep -qw -- --prep ; then
  exit 0
fi


# Everything below this line must be executed by root user (SRC no longer used):


# Prepare the kernel source for packaging:
( cd /usr/src/linux-${KVER}
  # This is where you optionally create a new kernel configuration:
  ARCH=$KARCH make $KCONF
  ARCH=$KARCH make oldconfig 1>/dev/null 2>&1
  # Run a test build, and clean up after:
  ARCH=$KARCH make -j ${NUMJOBS} || exit 1
  ARCH=$KARCH make clean
  # This makes sure that bounds.h is included:
  ARCH=$KARCH make prepare
  find . -name ".*tmp*" -exec rm "{}" \;
  find . -name *zImage -exec rm "{}" \;
  find . -name *.o -exec rm "{}" \;
  #find . -name modules.builtin -exec rm "{}" \;
  #find . -name modules.order -exec rm "{}" \;
  rm -f .config.old
  rm .version
)


# Make kernel-source package:
mkdir -p $OUTPUT/package-kernel-source/usr/src
( cd $OUTPUT/package-kernel-source/usr/src
  mv /usr/src/linux-${KVER} .
  ln -sf linux-${KVER} linux
  cd $OUTPUT/package-kernel-source
  mkdir -p install
  cat $CWD/slack-desc/slack-desc.kernel-source > install/slack-desc
  /sbin/makepkg -l y -c n ../kernel-source-$(echo ${KVER}-${PLATFORM} | tr - _)-noarch-$BUILD.txz
  rm -rf $OUTPUT/package-kernel-source
)
mkdir -p $OUTPUT/packages/linux-${KVER}
mv $OUTPUT/kernel-source*txz $OUTPUT/packages/linux-${KVER}

# Install the kernel-source package we just created:
rm -rf /usr/src/linux-$KVER
installpkg $OUTPUT/packages/linux-${KVER}/kernel-source-$(echo ${KVER}-${PLATFORM} | tr - _)-noarch-$BUILD.txz

# If we did just create a new .config file, secure it:
if [ ! -e $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER} ]; then
  install -m0644 /usr/src/linux-${KVER}/.config $CWD/configs-${ARCH}/config-${PLATFORM}-${KVER}
fi

# Copy the config file to the source directory as well:
mkdir -p $OUTPUT/source/linux-${KVER}
cp -a /usr/src/linux-${KVER}/.config $OUTPUT/source/linux-${KVER}/config-${PLATFORM}-${KVER}


# Create the kernel-headers package:
rm -rf $OUTPUT/package-kernel-headers
mkdir -p $OUTPUT/package-kernel-headers/usr
( cd /usr/src/linux-${KVER}
  make headers_install ARCH=${HEADERS_ARCH} INSTALL_HDR_PATH=$OUTPUT/package-kernel-headers/usr
  cd $OUTPUT/package-kernel-headers/usr/include || exit 1
  # Remove the kernel-headers version of /usr/include/scsi/scsi.h
  # - we use the file included with glibc.
  rm -f scsi/scsi.h
  mv asm asm-${HEADERS_ARCH}
  ln -sf asm-${HEADERS_ARCH} asm
  find . -name ".??*" -exec rm -f {} \;
  cd $OUTPUT/package-kernel-headers
  mkdir -p install
  cat $CWD/slack-desc/slack-desc.kernel-headers > install/slack-desc
  makepkg -l y -c n ../kernel-headers-$(echo ${KVER}-${PLATFORM} | tr - _)-$HEADERS_ARCH-$BUILD.txz
)
rm -rf $OUTPUT/package-kernel-headers
mv $OUTPUT/kernel-headers*txz $OUTPUT/packages/linux-${KVER}


echo "Compiling the kernel..."
# Next step, compile the kernel:
( cd /usr/src/linux-${KVER}
  ARCH=$KARCH make -j ${NUMJOBS} || exit 1
  case "$HEADERS_ARCH" in
  arm)
    #ARCH=$KARCH make zImage || exit 1
    # Build the U-Boot image:
    ARCH=$KARCH make uImage || exit 1

    case "$PLATFORM" in
    exynos5)
      # Create .dtb files
      ARCH=$KARCH make dtbs
      # Create FIT image for nv-U-boot:
      cp $CWD/its/${PLATFORM}.its arch/${HEADERS_ARCH}/boot/kernel.its
      cd arch/${HEADERS_ARCH}/boot
      mkimage -f kernel.its zImage
      cp -v zImage zImage.uimg
      ;;
    esac

    mkdir -p $OUTPUT/kernels/$PLATFORM
    cp -a /usr/src/linux-${KVER}/System.map $OUTPUT/kernels/$PLATFORM/System.map
    gzip -9 $OUTPUT/kernels/$PLATFORM/System.map
    cp -a /usr/src/linux-${KVER}/.config $OUTPUT/kernels/$PLATFORM/config
    # One or more of these kernel images may not exist for your platform:
    cp -a /usr/src/linux-${KVER}/arch/${HEADERS_ARCH}/boot/zImage $OUTPUT/kernels/$PLATFORM/zImage 
    cp -a /usr/src/linux-${KVER}/arch/${HEADERS_ARCH}/boot/zImage.uimg $OUTPUT/kernels/$PLATFORM/zImage.uimg
    cp -a /usr/src/linux-${KVER}/arch/${HEADERS_ARCH}/boot/uImage $OUTPUT/kernels/$PLATFORM/uImage
    ;;
  *)
    ARCH=$KARCH make bzImage || exit 1
    mkdir -p $OUTPUT/kernels/$PLATFORM
    cp -a /usr/src/linux-${KVER}/System.map $OUTPUT/kernels/$PLATFORM/System.map
    gzip -9 $OUTPUT/kernels/$PLATFORM/System.map
    cp -a /usr/src/linux-${KVER}/.config $OUTPUT/kernels/$PLATFORM/config
    cp -a /usr/src/linux-${KVER}/arch/${HEADERS_ARCH}/boot/bzImage $OUTPUT/kernels/$PLATFORM/bzImage
    ;;
  esac
) || exit 1


# We will package the kernel later.


# At this point, we need to check the actual kernel release. It may be different
# than the version of the source tarball (3.4 -> 3.4.0 for instance):
# The value $KREL will be used in module directory etc.
KREL=$(cat /usr/src/linux-${KVER}/include/config/kernel.release)


echo "Building modules for ${KREL}..."
# Note: this deletes your existing module directory!
rm -rf /lib/modules/${KREL}
( cd /usr/src/linux-${KVER}
  ARCH=$KARCH make -j ${NUMJOBS} modules || exit 1
  echo "Installing kernel modules..."
  ARCH=$KARCH make modules_install || exit 1
) || exit 1


# Calculate module dependencies now, so that we can run mkinitrd later:
echo "Calculating module dependencies for $KREL..."
rm -f /lib/modules/$KREL/modules.*
/sbin/depmod -a -e -b / -F /usr/src/linux-${KVER}/System.map $KREL


echo "Building the kernel-modules package..."
mkdir -p $OUTPUT/package-kernel-modules-$PLATFORM
( cd $OUTPUT/package-kernel-modules-$PLATFORM
  mkdir -p lib/modules
  cp -a /lib/modules/${KREL} lib/modules/
  mkdir -p etc/rc.d
  cat $CWD/sources/modules/rc.modules.new > etc/rc.d/rc.modules-${KREL}.new
  chmod 755 etc/rc.d/rc.modules-${KREL}.new

  mkdir -p install
  cat $CWD/slack-desc/slack-desc.kernel-modules > install/slack-desc

  makepkg -l y -c n ../kernel-modules-$PLATFORM-$(echo ${KVER}-${PLATFORM} | tr - _)-$ARCH-$BUILD.txz
)
rm -rf $OUTPUT/package-kernel-modules-$PLATFORM
mkdir -p $OUTPUT/packages/linux-${KVER}
mv $OUTPUT/kernel-modules-$PLATFORM*txz $OUTPUT/packages/linux-${KVER}
installpkg $OUTPUT/packages/linux-${KVER}/kernel-modules-$PLATFORM-$(echo ${KVER}-${PLATFORM} | tr - _)-${ARCH}-${BUILD}.txz


# For the arm kernels, we use a U-Boot "generic" kernel plus initrd:
# Generic requirements:
# Filesystems:
INITRDFS="vfat:jbd:jbd2:nls:exportfs:binfmt_misc:md:dm-mod:mbcache:ext2:ext3:ext4:reiserfs:jfs:xfs:fscache"
# Generic SCSI drivers & low-level drivers for discs/media:
INITRDSCSI="sg:scsi_mod:sd_mod:cdrom:sr_mod:scsi_tgt:mmc_block"
# Network filesystems:
INITRDNETFS="nfs:lockd:nfs_common"
# USB hubs & support mods, including interface devices (USB keyboards etc)
# followed by some specific device drivers.
INITRDUSB="ehci-hcd:uhci_hcd:usbhid:ohci_hcd:hid:usbcore:usb-storage:ums-cypress:ums-usbat:ums-freecom:ums-isd200:ums-sddr09:ums-sddr55:ums-alauda:ums-jumpshot:ums-onetouch"
# For SDHC cards:
INITRDCARDS="mvsdio"
# Additional stuff such as Netconsole (useful for debugging on machines without a serial cable)
# Note: ':' at the beginning is on purpose!
# INITRDADDITIONS=":netconsole"

case "$PLATFORM" in
  tegra)
    # Network interface card:
    # This one needs a binary blob, which we patch into the kernel.
    INITRDNETDEV="r8169"
    # SATA support:
    # The Trimslice's SATA is on an internal USB host.
    INITRDSATA="libata"
    # Console video:
    # The Trimslice uses the Tegra module,
    # which we need to compile into the Kernel.
    #INITRDVIDEO="xgifb" 
    # Subsystems for System on Chip - SoC:
    # (Some of these may not be required)
    INITRDSOC="i2c-tegra:rtc-em3027:spi-tegra"

    # Wait 6 seconds for the USB discs to spin up.  
    mkinitrd \
      -R \
      -L \
      -u \
      -w 6 \
      -k $KREL \
      -s $TMPBUILD/initrd-tree \
      -m $INITRDSOC:$INITRDSCSI:$INITRDSATA:$INITRDUSB:$INITRDFS:$INITRDNETDEV:$INITRDNETFS:$INITRDCARDS${INITRDADDITIONS} \
      -o /initrd-$PLATFORM.gz
      #-o $OUTPUT/kernels/$PLATFORM/initrd-$PLATFORM.gz
      # Creating it in / avoids an ugly bit of output at boot that contains
      # the path where it was built.  It just looks nicer this way :-)
      mkdir -p $OUTPUT/kernels/$PLATFORM
      mv -fv /initrd-$PLATFORM.gz  $OUTPUT/kernels/$PLATFORM/

    # Create a uInitrd for U-boot:
    cd $TMPBUILD
    mkimage \
      -A arm \
      -O linux \
      -T ramdisk \
      -C gzip \
      -n "Slackware ARM-$PLATFORM Initial RAM disk" \
      -d $OUTPUT/kernels/$PLATFORM/initrd-$PLATFORM.gz \
      $OUTPUT/kernels/$PLATFORM/uinitrd-$PLATFORM
    ;;
  exynos5)
    # Network interface card:
    #INITRDNETDEV=""
    # SATA support:
    #INITRDSATA=""
    # Console video:
    #INITRDVIDEO="" 
    # Subsystems for System on Chip - SoC:
    # (Some of these may not be required)
    INITRDSOC="i2c-tegra:rtc-em3027:spi-tegra"

    mkinitrd \
      -R \
      -L \
      -u \
      -k $KREL \
      -s $TMPBUILD/initrd-tree \
      -m $INITRDSOC:$INITRDSCSI:$INITRDSATA:$INITRDUSB:$INITRDFS:$INITRDNETDEV:$INITRDNETFS:$INITRDCARDS${INITRDADDITIONS} \
      -o /initrd-$PLATFORM.gz
      #-o $OUTPUT/kernels/$PLATFORM/initrd-$PLATFORM.gz
      # Creating it in / avoids an ugly bit of output at boot that contains
      # the path where it was built.  It just looks nicer this way :-)
      mkdir -p $OUTPUT/kernels/$PLATFORM
      mv -fv /initrd-$PLATFORM.gz  $OUTPUT/kernels/$PLATFORM/

    # Create a uInitrd for U-boot:
    cd $TMPBUILD
    mkimage \
      -A arm \
      -O linux \
      -T ramdisk \
      -C gzip \
      -n "Slackware ARM-$PLATFORM Initial RAM disk" \
      -d $OUTPUT/kernels/$PLATFORM/initrd-$PLATFORM.gz \
      $OUTPUT/kernels/$PLATFORM/uinitrd-$PLATFORM
    ;;
  *)
    ;;
esac


# Make kernel package:
echo "Building the kernel-$PLATFORM package..."
mkdir -p $OUTPUT/package-kernel-$PLATFORM
( cd $OUTPUT/package-kernel-$PLATFORM

  if [ -f $OUTPUT/kernels/$PLATFORM/uImage  ]; then
    KERNEL=$OUTPUT/kernels/$PLATFORM/uImage
  elif [ -f $OUTPUT/kernels/$PLATFORM/zImage  ]; then
    KERNEL=$OUTPUT/kernels/$PLATFORM/zImage
  else
    KERNEL=$OUTPUT/kernels/$PLATFORM/bzImage
  fi

  mkdir -p boot
  cp $KERNEL boot/uImage-$PLATFORM-${KVER}
  ( cd boot ; ln -sf uImage-$PLATFORM-${KVER} uImage-$PLATFORM )
  gunzip -cd $OUTPUT/kernels/$PLATFORM/System.map.gz > boot/System.map-$PLATFORM-${KVER}
  ( cd boot ; ln -sf System.map-$PLATFORM-${KVER} System.map-$PLATFORM )
  cp $OUTPUT/kernels/$PLATFORM/config boot/config-$PLATFORM-${KVER}
  ( cd boot ; ln -sf config-$PLATFORM-${KVER} config-$PLATFORM )

  # Put a copy of the initial RAM disk into the $PKG's /boot
  # This allows devices whose boot loader can read the partition where
  # /boot resides can have a generic initrd to boot into after installation.
  # This 'uinitrd' is for devices using the 'Das U-Boot' Linux loader.
  install -pm644 $OUTPUT/kernels/$PLATFORM/uinitrd-$PLATFORM boot/uinitrd-$PLATFORM-$KVER
  ( cd boot ; ln -sf uinitrd-$PLATFORM-$KVER uinitrd-$PLATFORM )

  mkdir -p install
  cat $CWD/slack-desc/slack-desc.kernel-$PLATFORM > install/slack-desc

  /sbin/makepkg -l y -c n ../kernel-$PLATFORM-$(echo ${KVER}-${PLATFORM} | tr - _)-$ARCH-$BUILD.txz
)

rm -rf $OUTPUT/package-kernel-$PLATFORM
mkdir -p $OUTPUT/packages/linux-${KVER}
mv $OUTPUT/kernel-$PLATFORM*txz $OUTPUT/packages/linux-${KVER}
installpkg $OUTPUT/packages/linux-${KVER}/kernel-$PLATFORM-$(echo ${KVER}-${PLATFORM} | tr - _)-${ARCH}-${BUILD}.txz

# The end.