#!/bin/sh

### Modifiable variables
KERNEL_VARIANT="lts"
#KERNEL_VARIANT="virt"
MICROCODE="intel"
#MICROCODE="amd"
BOOT_PARTITION_SIZE="256M"

#==================================================#

# Add basic dependencies
apk update && apk add lsblk

#==================================================#

printf '\n'
printf '==============Warning==============\n'
printf '\n'
printf 'This script will format your entire disk!\n'
printf 'Make sure you know what you are doing!\n'
printf 'The system will be installed on the EXT4 partition.\n'
printf 'Unified Kernel Image (UKI) and Secure Boot\n'
printf 'will be automatically enabled (if enabled in UEFI).\n'
printf 'The default memory allocator will be set to mimalloc.\n'
printf 'You can open this script and edit the "Modifiable Variables" section.\n'
printf 'If you want to exit press Ctrl+C.\n'
printf '\n'
printf '==========Available disks==========\n'
printf '\n'

# Disk selector
lsblk -d | tail -n+2 | awk '{print $1" "$4}'
printf '\n'
read -p "Select the disk on which you want to install the system: " SELECTED_DRIVE

INSTALL_DRIVE=/dev/$SELECTED_DRIVE

printf 'Your installation disk is '$INSTALL_DRIVE'\n'

if [ "$INSTALL_DRIVE" = "/dev/sda" -o "$INSTALL_DRIVE" = "/dev/sdb" -o "$INSTALL_DRIVE" = "/dev/sdc" -o "$INSTALL_DRIVE" = "/dev/sdd" ]
then 
        BOOT_PART="$INSTALL_DRIVE"1
        ROOT_PART="$INSTALL_DRIVE"2
    printf 'Your BOOT partition is '$BOOT_PART'\n'
    printf 'Your ROOT partition is '$ROOT_PART'\n'
fi

if [ "$INSTALL_DRIVE" = "/dev/vda" -o "$INSTALL_DRIVE" = "/dev/vdb" -o "$INSTALL_DRIVE" = "/dev/vdc" -o "$INSTALL_DRIVE" = "/dev/vdd" ]
then 
        BOOT_PART="$INSTALL_DRIVE"1
        ROOT_PART="$INSTALL_DRIVE"2
    printf 'Your BOOT partition is '$BOOT_PART'\n'
    printf 'Your ROOT partition is '$ROOT_PART'\n'
fi

if [ "$INSTALL_DRIVE" = "/dev/nvme0n1" -o "$INSTALL_DRIVE" = "/dev/nvme0n2" -o "$INSTALL_DRIVE" = "/dev/nvme0n3" -o "$INSTALL_DRIVE" = "/dev/nvme0n4" ]
then 
        BOOT_PART="$INSTALL_DRIVE"p1
        ROOT_PART="$INSTALL_DRIVE"p2
    printf 'Your BOOT partition is '$BOOT_PART'\n'
    printf 'Your ROOT partition is '$ROOT_PART'\n'
fi

printf '\n'

#==================================================#

# Modify installation script
sed -i '7i BOOTLOADER="none"' /usr/sbin/setup-disk

#==================================================#

# Add repos
rm /etc/apk/repositories
printf 'http://ftp.icm.edu.pl/pub/Linux/distributions/alpine/edge/main\n' >> /etc/apk/repositories
printf 'http://ftp.icm.edu.pl/pub/Linux/distributions/alpine/edge/community\n' >> /etc/apk/repositories
printf 'http://ftp.icm.edu.pl/pub/Linux/distributions/alpine/edge/testing\n' >> /etc/apk/repositories

#==================================================#

# Add disk packages
apk update && apk add dosfstools e2fsprogs efibootmgr

#==================================================#

# Cleaning disk
dd if=/dev/zero of=$INSTALL_DRIVE bs=4096 count=1
sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | fdisk $INSTALL_DRIVE
  d # delete partition
  1 # delete partition 1
  d # delete partition
  2 # delete partition 2
  d # delete partition
  3 # delete partition 3
  d # delete partition
  4 # delete partition 4
  d # delete partition
  5 # delete partition 5
  p # print the in-memory partition table
  w # write the partition table
  q # and we're done
EOF

#==================================================#

# Make partition table
sed -e 's/\s*\([\+0-9a-zA-Z]*\).*/\1/' << EOF | fdisk $INSTALL_DRIVE
  g # set gpt table
  n # new partition
  p # primary partition
  1 # partition number 1
    # default - start at beginning of disk 
  +$BOOT_PARTITION_SIZE # EFI parttion
  t # change partition type step 1
  ef # change partition type step 2
  n # new partition
  p # primary partition
  2 # partion number 2
    # default, start immediately after preceding partition
    # default, extend partition to end of disk
  a # make a partition bootable
  1 # bootable partition is partition 1 -- /dev/sda1
  p # print the in-memory partition table
  w # write the partition table
  q # and we're done
EOF

#==================================================#

# Format partitions
mkfs.vfat -F 32 $BOOT_PART && fatlabel $BOOT_PART ESP && mkfs.ext4 -F -L "Alpine Linux" $ROOT_PART

#==================================================#

# Mount partitions
mount -t ext4 $ROOT_PART /mnt && mkdir -p /mnt/boot && mount -t vfat $BOOT_PART /mnt/boot && rm -rf /mnt/lost+found

#==================================================#

# Base install
setup-disk -m sys /mnt

#==================================================#

# Create UKI dirs
mkdir -p /mnt/etc/kernel && mkdir -p /mnt/etc/kernel-hooks.d

#==================================================#

# Create cmdline
blkid $ROOT_PART | awk '{print $4}' | sed 's/"//g' $1 >> root_uuid.txt
ROOT_UUID=$(cat root_uuid.txt)
rm root_uuid.txt
printf 'root='$ROOT_UUID' modules=sd-mod,usb-storage,ext4 rootfstype=ext4 rw '$MICROCODE'_iommu=on sysrq_always_enabled=1 audit=0 quiet loglevel=3 bgrt_disable\n' >> /mnt/etc/kernel/cmdline

#==================================================#

# Create UKI update script
printf '#!/bin/sh\n' >> /mnt/etc/kernel-hooks.d/99-zz_uki.sh
printf 'uki=/boot/alpine.efi\n' >> /mnt/etc/kernel-hooks.d/99-zz_uki.sh
printf 'ukify build --linux /boot/'vmlinuz-$KERNEL_VARIANT' --initrd /boot/'$MICROCODE-ucode.img' --initrd /boot/'initramfs-$KERNEL_VARIANT' --cmdline @/etc/kernel/cmdline --os-release @/usr/lib/os-release --output $uki\n' >> /mnt/etc/kernel-hooks.d/99-zz_uki.sh
printf 'sbctl sign $uki\n' >> /mnt/etc/kernel-hooks.d/99-zz_uki.sh
chmod a+x /mnt/etc/kernel-hooks.d/99-zz_uki.sh

#==================================================#

# Stuff in chroot
cat << EOF | chroot /mnt
apk add ukify sbctl systemd-efistub mimalloc2
sbctl create-keys && sbctl enroll-keys -m ; apk add $MICROCODE-ucode kernel-hooks
sed  -i '3i LD_PRELOAD=/usr/lib/libmimalloc.so.2' /etc/profile
sed  -i '4i' /etc/profile
EOF

#==================================================#

# Add bootable UEFI entry
efibootmgr -c -d $INSTALL_DRIVE -L "Alpine Linux" -l '\alpine.efi' -u

#==================================================#

# Unmount partitions and reboot
umount $BOOT_PART ; umount $ROOT_PART ; reboot

#==================================================#