#!/bin/bash

# package name
PNAME="memtest86+"

# binary image
BNAME="memtest86+"

# ELF image
ELFNAME="elf-$BNAME"

# executable image to be installed
ENAME="$ELFNAME"

# GRUB 2 template
G2TEMPL="20_memtest86+"

# GRUB 2 environment file
CONF_FILE="/etc/memtest86+.conf"

# GRUB legacy configuration file
GRUBCONF="/boot/grub/grub.conf"

# GRUB2 configuration file
GRUB2CFG="/boot/grub2/grub.cfg"

# GRUB2 environment variable to control image type
CONF_VAR="INSTALL_ELF"

# whether to install ELF image
ELF=1

if [ "$1" = "--help" -o "$1" = "-h" ]; then
    cat <<:EOF
usage: memtest-setup [OPTIONS]

This utility installs Memtest86+ into your GRUB boot loader menu.
It supports both GRUB 2 and GRUB Legacy (i.e. GRUB 0.9x).
In case of GRUB 2 it installs GRUB 2 template into /etc/grub.d and GRUB 2
config needs to be regenerated manually by running:

grub2-mkconfig -o $GRUB2CFG

This is not done automatically because it could  overwrite any custom changes
in /boot/grub2/grub.cfg.

OPTIONS:
  -e , --elf     installs ELF image (the default)
  -b , --bin     installs binary image (non-ELF)
  -h , --help    show this help

:EOF
    exit 0
fi

[ "$1" = "-b" -o "$1" = "--bin" ] && ELF=0
[ "$1" = "-e" -o "$1" = "--elf" ] && ELF=1

if [ "$ELF" = 1 ]; then
  # BANNER_SUFFIX needs to be simultaneously changed also in grub2 template
  BANNER_SUFFIX=
  ENAME="$ELFNAME"
else
  ELF=0
  BANNER_SUFIX="(non-ELF)"
  ENAME="$BNAME"
fi

if [ -d /sys/firmware/efi ]; then
    echo "ERROR: memtest86+ does not support EFI platforms."
    exit 254
fi

if [ ! -r "$GRUBCONF" -a ! -r "$GRUB2CFG" ]; then
   echo "ERROR: unable to read grub configuration file. Do you have enough permissions?"
   echo "Try to run as root."
   exit 249
fi

if [ -f "$GRUB2CFG" ]; then
    echo "GRUB 2 detected, installing template..."
    if [ ! -d /etc/grub.d ]; then
        echo "ERROR: unable to find /etc/grub.d"
        exit 253
    fi
    if [ ! -r /usr/share/memtest86+/$G2TEMPL ]; then
        echo "ERROR: unable to find GRUB 2 template."
        exit 251
    fi
    if ! cp /usr/share/memtest86+/$G2TEMPL /etc/grub.d; then
        echo "ERROR: unable to copy GRUB 2 template, do you have write permission to"
        echo "/etc/grub.d?"
        # EX_IOERR
        exit 74
    fi
    if [ ! -w "$CONF_FILE" ]
    then
        echo "ERROR: file '$CONF_FILE' is not writable."
        exit 250
    fi
    chmod a+x /etc/grub.d/$G2TEMPL
    echo "GRUB 2 template installed."
    echo "Do not forget to regenerate your grub.cfg by:"
    echo "  # grub2-mkconfig -o $GRUB2CFG"
else
    MTVERSION=`rpm -q --qf '%{version}' $PNAME`
    MTPATH="/boot/$ENAME-$MTVERSION"

    if [ ! -r "$GRUBCONF" ]; then
        echo "ERROR: $GRUBCONF not found or not readable."
        exit 252
    fi

    MENT=`cat /boot/grub/grub.conf | grep "$ENAME-$MTVERSION"` &> /dev/null
    if [ "$MENT" != "" ]; then
        echo "$MTPATH is already configured. Exiting..."
        exit 0
    fi

    if [ ! -f $MTPATH ]; then
        echo "ERROR: $MTPATH does not exist."
        exit 255
    fi

    /sbin/new-memtest-pkg --install $MTVERSION --banner="Memtest86+${BANNER_SUFFIX}" --kernel-name="$ENAME"
    RETVAL="$?"

    if [ "$RETVAL" != "0" ]; then
        echo "ERROR: grubby failed to configure your bootloader for $MTPATH."
        exit $RETVAL
    else
        [ "$ELF" = 1 ] && sed -i -e"s,kernel \(/boot\)\?/$ENAME,kernel --type=netbsd \1/$ENAME," /boot/grub/grub.conf
        sed -i -e"s,/$ENAME-$MTVERSION.*,/$ENAME-$MTVERSION," /boot/grub/grub.conf
    fi
fi

# update/add configuration variable to the configuration file
if grep -q "^\s*$CONF_VAR\s*=" "$CONF_FILE"
then
    sed -i "/^\s*$CONF_VAR\s*=/ s/\(\s*$CONF_VAR\s*=[\"']\?\)[^\"']*\([\"']\?\s*\)/\1${ELF}\2/g" "$CONF_FILE"
else
    echo "$CONF_VAR=\"$ELF\"" >> "$CONF_FILE"
fi

echo "Setup complete."