#!/bin/sh

BOOT_EFI_DIST="/boot/zfsbootmenu-recovery-x86_64-v3.1.0-linux6.18.EFI"

ROOT_DATASET="zpool1/ROOT"
BOOT_KERNEL="vmlinuz-linux-custom"
BOOT_CMDLINE="rw delayacct audit=0 init_on_alloc=0 init_on_free=0 kvm-intel.nested=1 page_alloc.shuffle=1 intel_iommu=igfx_off iommu=pt msr.allow_writes=on retbleed=stuff"

# rd.debug rd.log=all printk.devkmsg=on
# crashkernel=512M

# efibootmgr -c -b 0000 -d /dev/nvme0n1 -p 1 -L "ZBM" -l '\EFI\BOOT\BOOTX64.EFI'
# efibootmgr -c -b 0001 -d /dev/nvme0n1 -p 1 -L "ZBM Backup" -l '\EFI\BOOT\BOOT2X64.EFI'
# efibootmgr -o 0000,0001,0003

# https://docs.zfsbootmenu.org/en/v3.1.x/general/uefi-booting.html
# https://github.com/rhboot/efibootmgr

#### Nothing to change below here

ESP_MOUNT="/boot/efi"
BOOT_EFI="$ESP_MOUNT/EFI/BOOT/BOOTX64.EFI"
BOOT2_EFI="$ESP_MOUNT/EFI/BOOT/BOOT2X64.EFI"

# Mount ESP
if ! mountpoint -q "$ESP_MOUNT"; then
	echo "*** Mounting ESP"
	mount "$ESP_MOUNT" || exit 1
	if ! mountpoint -q "$ESP_MOUNT"; then
		echo "ESP problem, not a mountpoint"
		exit 1
	fi
else
    echo "Warning: ESP already mounted"
fi

# Check that all necessary files exist
for file in "$BOOT_EFI" "$BOOT_EFI_DIST" /etc/hostid /proc/uptime; do
    if [ ! -f "$file" ]; then
        echo "File $BOOT_EFI missing." >&2
        exit 1
    fi
done

# EFI bundle backup
if [ ! -e "$BOOT2_EFI" ]; then
    echo "*** Initial backup BOOT2X64.EFI"
    cp -avf "$BOOT_EFI" "$BOOT2_EFI"
else
    current_time=$(date +%s)
    uptime_seconds=$(awk '{print int($1)}' /proc/uptime)
    boot_time=$((current_time - uptime_seconds))
    file_mtime=$(stat -c %Y "$BOOT2_EFI")
    if [ "$file_mtime" -lt "$boot_time" ]; then
        echo "*** Backup BOOT2X64.EFI"
        cp -v "$BOOT_EFI" "$BOOT2_EFI"
    else
        echo "*** Backup BOOT2X64.EFI skipped, too recent"
    fi
fi

echo "*** Boot dataset settings"
zfs set org.zfsbootmenu:commandline="$BOOT_CMDLINE" "$ROOT_DATASET"
zfs set org.zfsbootmenu:kernel="$BOOT_KERNEL" "$ROOT_DATASET"
zfs get all -s local "$ROOT_DATASET" | grep zfsbootmenu | awk '{ $1=$1; print }'

echo "*** Writing BOOTX64.EFI"
HOSTID=$(od -An -tx4 /etc/hostid | tr -d " ")
/boot/zbm-kcl -r zbm.timeout -a zbm.timeout=5 -a spl.spl_hostid=0x"$HOSTID" -o "$BOOT_EFI" "$BOOT_EFI_DIST"
/boot/zbm-kcl "$BOOT_EFI"

echo "*** Unmounting ESP"
umount "$ESP_MOUNT"
exit 0