#!/bin/sh

set -e

gen_efi_boot_img(){
	local platform="$1"
	local efi_name="$2"
	local netboot_prefix="$3"
	local outdir="grub-efi-temp-${platform}"
	"${LIVE_BUILD_PATH}/efi-image" "/$outdir" "$platform" "$efi_name" "$netboot_prefix"
	mkdir -p /grub-efi-temp/EFI/boot
	mcopy -m -n -i /$outdir/efi.img '::efi/boot/boot*.efi' /grub-efi-temp/EFI/boot
	cp -a ""/$outdir/* "/grub-efi-temp/"

	# Secure Boot support:
	# - create the EFI directory in the ESP with uppercase letters to make
	#   certain firmwares (eg: TianoCore) happy
	# - use shim as the boot<arch>.efi that gets loaded first by the firmware
	# - drop a grub.cfg (same reason as below) in the cfg directory as configured
	#   by the signed grub efi binary creation. This is set dynamically when grub2 is
	#   built with the ouput of dpkg-vendor, and can be overridden by the builder, so
	#   we do the same here in live-build.
	# - the source paths are taken from shim-signed:
	#    https://packages.debian.org/sid/amd64/shim-signed/filelist
	#   and grub-efi-amd64-signed, currently in Ubuntu:
	#    https://packages.ubuntu.com/xenial/amd64/grub-efi-amd64-signed/filelist
	#    https://packages.ubuntu.com/bionic/arm64/grub-efi-arm64-signed/filelist
	#   E.g., gcdx64.efi.signed is the boot loader for removable device, like CD or
	#   USB flash drive, while grubx64.efi.signed is for hard drive.
	#   Therefore here gcdx64.efi.signed is used for amd64 and gcdaa64.efi.signed is
	#   for arm64.
	if [ -r /usr/lib/grub/$platform-signed/gcd$efi_name.efi.signed -a 			-r /usr/lib/shim/shim$efi_name.efi.signed -a 			"enable" != "disable" ]; then
		cp -a /usr/lib/grub/$platform-signed/gcd$efi_name.efi.signed 			/grub-efi-temp/EFI/boot/grub$efi_name.efi
		cp -a /usr/lib/shim/shim$efi_name.efi.signed 			/grub-efi-temp/EFI/boot/boot$efi_name.efi
	fi
}

PRE_EFI_IMAGE_PATH="/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
if [ ! -e "" ] ; then
	LIVE_BUILD_PATH="/usr/lib/live/build"
else
	LIVE_BUILD_PATH="/scripts/build"
fi

PATH="/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/working_dir/tmp/amd64/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:${LIVE_BUILD_PATH}" # Make sure grub-cpmodules is used as if it was installed in the system

case "amd64" in
	amd64|i386)
		gen_efi_boot_img "x86_64-efi" "x64" "debian-live/amd64"
		gen_efi_boot_img "i386-efi" "ia32" "debian-live/i386"
		PATH="${PRE_EFI_IMAGE_PATH}"
		;;
	arm64)
		gen_efi_boot_img "arm64-efi" "aa64" "debian-live/arm64"
		PATH="${PRE_EFI_IMAGE_PATH}"
		;;
	armhf)
		gen_efi_boot_img "arm-efi" "arm" "debian-live/arm"
		PATH="${PRE_EFI_IMAGE_PATH}"
		;;
esac


# On some platforms the EFI grub image will be loaded, so grub's root
# variable will be set to the EFI partition. This means that grub will
# look in that partition for a grub.cfg file, and even if it finds it
# it will not be able to find the vmlinuz and initrd.
# Drop a minimal grub.cfg in the EFI partition that sets the root and prefix
# to whatever partition holds the /.disk/info file, and load the grub
# config from that same partition.
mkdir -p /grub-efi-temp-cfg
cat >/grub-efi-temp-cfg/grub.cfg <<EOF
search --set=root --file /.disk/info
set prefix=(\$root)/boot/grub
configfile (\$root)/boot/grub/grub.cfg
EOF
# Set the timestamp within the efi.img file
touch /grub-efi-temp-cfg/grub.cfg -d@1676720481

# The code below is adapted from tools/boot/jessie/boot-x86
# in debian-cd

# Stuff the EFI boot files into a FAT filesystem, making it as
# small as possible.  24KiB headroom seems to be enough;
# (x+31)/32*32 rounds up to multiple of 32.
# This is the same as in efi-image, but we need to redo it here in
# the case of a multi-arch amd64/i386 image

size=0
for file in /grub-efi-temp/EFI/boot/*.efi 		/grub-efi-temp-cfg/grub.cfg; do
	size=$(($size + $(stat -c %s "$file")))
done

# directories: EFI EFI/boot boot boot/grub
size=$(($size + 4096 * 4))

blocks=$((($size / 1024 + 55) / 32 * 32 ))

rm -f /grub-efi-temp/boot/grub/efi.img
# The VOLID must be (truncated to) a 32bit hexadecimal number
mkfs.msdos -C "/grub-efi-temp/boot/grub/efi.img" $blocks -i 63f0b961 >/dev/null
mmd -i "/grub-efi-temp/boot/grub/efi.img" ::EFI
mmd -i "/grub-efi-temp/boot/grub/efi.img" ::EFI/boot
mcopy -m -o -i "/grub-efi-temp/boot/grub/efi.img" /grub-efi-temp/EFI/boot/*.efi 	"::EFI/boot"

mmd -i "/grub-efi-temp/boot/grub/efi.img" ::boot
mmd -i "/grub-efi-temp/boot/grub/efi.img" ::boot/grub
mcopy -m -o -i "/grub-efi-temp/boot/grub/efi.img" /grub-efi-temp-cfg/grub.cfg 	"::boot/grub"