build

#!/usr/bin/env sh

output="BOOTX64.EFI"
if [ $# -gt 0 ]; then
  output="$1"
fi

dir="."
if [ -d "$1" ]; then
  dir="$1"
  output="$output.efi"
fi

echo "Using $dir/grub.cfg for $output"
echo "Grub modules dir: ${ENV_GRUB_MODULES_DIR:=/usr/lib/grub/x86_64-efi/}"
echo "Compression: ${ENV_GRUB_COMPRESS_COMMAND:=xz -9}"
# xz -9
# gzip -9
# zstd does not seem to work
# compressing each file individually, xz seems to perform best

export MODULES="$ENV_GRUB_MODULES_BASE $ENV_GRUB_MODULES_FS $ENV_GRUB_MODULES_CRYPTO $ENV_GRUB_MODULES_LUKS"

(cd "$dir" \
  && rm -rf memdisk \
  && mkdir -p memdisk/boot/grub/x86_64-efi \
  && cd memdisk \
  && envsubst '$ENV_GRUB_CRYPTODISK_UUID $ENV_GRUB_FS_UUID $ENV_GRUB_HINT $ENV_GRUB_CHAINLOAD_PREFIX $ENV_GRUB_CHAINLOAD_EFI $ENV_GRUB_LOG_LEVEL $ENV_GRUB_RETRY_TIMEOUT $MODULES' \
    < ../grub.cfg.template | $ENV_GRUB_COMPRESS_COMMAND > boot/grub/grub.cfg \
  && for mod in $MODULES; do cat $ENV_GRUB_MODULES_DIR$mod.mod > boot/grub/x86_64-efi/$mod.mod; done \
  && for mod in normal fshelp extcmd net priority_queue bufio datetime boot terminal gettext echo sleep test configfile part_gpt fat search_label search_fs_file efinet diskfilter procfs afsplitter pbkdf2; do cat $ENV_GRUB_MODULES_DIR$mod.mod > boot/grub/x86_64-efi/$mod.mod; done \
  && (cd boot/grub && tar -c x86_64-efi | $ENV_GRUB_COMPRESS_COMMAND > ../x86_64-efi.tar.xz && rm -rf x86_64-efi) \
  && tar -cf ../memdisk.tar boot)

## create a efi grub boot image
## the config gets embedded and should decrypt the disk and chainload the grub residing there
## loaded modules should only be necessary for what's happening in the embedded script
## todo maybe some eyecandy --> distinguishable for me that everything works as it should ;D
grub-mkimage --config "initial.cfg" --compression auto --output "$output" \
  --format x86_64-efi --memdisk="$dir/memdisk.tar" \
    memdisk tar \
    loopback \
    `#gzio` \
    xzio \
    `#zstd`

## about the mods used
## ===================
# | mod            | description
# |----------------|--------------------
# | fat            | support read fat fs
# | part_gpt       | support gpt partitions
# | test           | command to test expressions
# | search         | to search for the root device
# | search_fs_uuid | to allow uuids for the search
# | cryptodisk     | encryption
# | luks           | luks encryption
# | lvm            | lvm support
# | xfs            | xfs support
# | ext2           | ext2 support (+ ext3/ext4)
# | configfile     | read the "chainloaded" configfile
# | gcry_sha256    | sha256 for encryption
# | gcry_sha512    | sha512
# | gcry_rijndael  | for encryption (AES)
# |----------------|--------------------
# | other interesting mods |
# |----------------|-------------------
# | gfmenu         | eyecandy?
# | hashsum        | check hashsums: to check external sources like images
# | jpeg           | eyecandy?
# | keystatus      | show a caps-lock warning ?
# | normal         | normal mode ?
# | png            | eyecandy?
# | probe          | easier info?
# | progress       | eyecandy?
# | verify         | check file signatures
# | gcry_rsa       | rsa signatures?