#!/bin/bash
# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*-
# ex: ts=8 sw=4 sts=4 et filetype=sh
#
# Author: Todor Minchev <todor.minchev@linux.intel.com>
# Modified-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
#
# Copyright © 2014 Intel Corporation
#
# Kernel installer script - installs kernel, initrd, kernel config 
# and system map and creates a bootloader entry for the new kernel
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# Arguments:
#   $1 - kernel version
#   $2 - kernel image file
#   $3 - kernel map file
#   $4 - default install path (blank if root directory)

KERNEL_VER=$1
KERNEL_IMAGE=$2
KERNEL_MAP=$3
INSTALL_PATH=${4%/}

BOOTLOADER=""
BOOT_MOUNTED=0

declare -a BOOT_OPTIONS

ret=0

validate_install_path ()
{
    if [ -n "$1" ]; then
        if [ ! -d "$1" ]; then
            echo -e "\n *** Invalid installation path *** : $1\n"    	1>&2
            exit 1
        fi
    fi
}

validate_kernel_version ()
{
    if [ -z "$1" ]; then
        echo -e "\n *** Kernel version not found *** \n"    		1>&2
        exit 1
    fi
}

validate_kernel_image ()
{
    if [ ! -f "$1" ]; then
        echo -e "\n *** Kernel image not found *** \n"    		1>&2
        echo -e "\n *** Please compile your kernel and modules *** \n" 	1>&2
        exit 1
    fi
}

validate_system_map ()
{
    if [ ! -f "$1" ]; then
        echo -e "\n *** Kernel map file not found *** \n"    		1>&2
        echo -e "\n *** Please compile your kernel *** \n"    		1>&2
        exit 1
    fi
}

validate_modules_install ()
{
    if [ ! -d "$1" ]; then
        echo -e "\n *** Kernel modules not found *** : $1\n"    	1>&2
        echo -e "\n *** Please run 'make modules_install' first*** \n"  1>&2
        exit 1
    fi
}

setup_install ()
{

    if [[ -f /etc/os-release ]]; then
        . /etc/os-release
    elif [[ -f /usr/lib/os-release ]]; then
        . /usr/lib/os-release
    fi

    if ! [[ $PRETTY_NAME ]]; then
        PRETTY_NAME="Linux $KERNEL_VERSION"
    fi

    if [[ -f /etc/kernel/cmdline ]]; then
        read -r -d '' -a BOOT_OPTIONS < /etc/kernel/cmdline
    fi

    if ! [[ ${BOOT_OPTIONS[*]} ]]; then
        read -r -d '' -a line < /proc/cmdline
        for i in "${line[@]}"; do
            [[ "${i#initrd=*}" != "$i" ]] && continue
            [[ "${i#BOOT_IMAGE=*}" != "$i" ]] && continue
            BOOT_OPTIONS+=("$i")
        done
    fi

    if ! [[ ${BOOT_OPTIONS[*]} ]]; then
        echo "Could not determine the kernel command line parameters." >&2
        echo "Please specify the kernel command line in /etc/kernel/cmdline!" >&2
        exit 1
    fi

    cp "$KERNEL_IMAGE" "${INSTALL_PATH}/vmlinuz-${KERNEL_VER}" &&
       chown root:root "${INSTALL_PATH}/vmlinuz-${KERNEL_VER}" &&
       chmod 0644 "${INSTALL_PATH}/vmlinuz-${KERNEL_VER}" || {
        echo "Could not copy '$KERNEL_IMAGE to '${INSTALL_PATH}/vmlinuz-${KERNEL_VER}'." >&2
        exit 1
    }

}

install_efi_kernel () {

    LOADER_ENTRY="${INSTALL_PATH}/loader/entries/linux-${KERNEL_VER}.conf"
    LOADER_CONF="${INSTALL_PATH}/loader/loader.conf"

    setup_install

    mkdir -p "${LOADER_ENTRY%/*}" || {
        echo "Could not create loader entry directory '${LOADER_ENTRY%/*}'." >&2
        exit 1
    }

    {
        echo "title      $PRETTY_NAME"
        echo "version    ${KERNEL_VER}"
        echo "options    ${BOOT_OPTIONS[*]}"
        echo "linux      /vmlinuz-${KERNEL_VER}"
    } > "$LOADER_ENTRY" || {
        echo "Could not create loader entry '$LOADER_ENTRY'." >&2
        exit 1
    }

    # Add timeout to boot menu if needed
    grep -q timeout ${LOADER_CONF} || echo "timeout 15" >> ${LOADER_CONF}

}

install_syslinux_kernel () {
    LOADER_CONF="${INSTALL_PATH}/syslinux.cfg"

    setup_install

    {
        echo "#"
        echo "# Installed from sources"
        echo "LABEL linux-${KERNEL_VER}"
        echo "  LINUX  vmlinuz-${KERNEL_VER}"
        echo "  APPEND ${BOOT_OPTIONS[*]}"
        echo "#"
    } >> "${LOADER_CONF}" || {
        echo "Cound not create loader entry " >&2
        exit 1
    }

    # Add timeout to boot menu if needed
    grep -q -i TIMEOUT ${LOADER_CONF}  || echo "TIMEOUT 150" >> ${LOADER_CONF}
    grep -q -i "PROMPT" ${LOADER_CONF} || echo "PROMPT 1" >> ${LOADER_CONF}

}

################  main  ################

validate_kernel_version ${KERNEL_VER}
validate_kernel_image ${KERNEL_IMAGE}
validate_system_map ${KERNEL_MAP}
validate_install_path ${INSTALL_PATH}

KERNEL_MODULES=${INSTALL_PATH%/*}/usr/lib/modules/${KERNEL_VER}
validate_modules_install ${KERNEL_MODULES}

if [ -d ${INSTALL_PATH}/loader ] ; then
    BOOTLOADER="systemd"
fi
if [ -f ${INSTALL_PATH}/syslinux.cfg ] ; then
    BOOTLOADER="syslinux"
fi

if [ -z "${BOOTLOADER}" ] ; then
    # Mount /boot partition
    systemctl start boot.mount
    ((ret+=$?))
    if [ ${ret} -eq 0 ] ; then
        BOOT_MOUNTED=1
    fi
    if [ -d ${INSTALL_PATH}/loader ] ; then
        BOOTLOADER="systemd"
    fi
    if [ -f ${INSTALL_PATH}/syslinux.cfg ] ; then
        BOOTLOADER="syslinux"
    fi
    if [ -z "${BOOTLOADER}" ] ; then
        echo "Cound not find boot loader" >&2
        exit 1
    fi
fi

if [ "${BOOTLOADER}" == "systemd" ] ; then
    # Based on systemd kernel-install plugin script
    install_efi_kernel
    ((ret+=$?))
else
    install_syslinux_kernel
    ((ret+=$?))
fi

if [ ${BOOT_MOUNTED} -eq 1 ] ; then
    # Unmount /boot partition
    systemctl stop  boot.mount
    ((ret+=$?))
fi

exit $ret