Add dual boot script (for use with Pop)

scripts/dual-boot.sh

+#!/usr/bin/env bash
+
+set -e
+
+if [ -n "$1" ]
+then
+    DISK="$1"
+else
+    DISK=/dev/disk/by-partlabel/REDOX_INSTALL
+fi
+
+if [ ! -b "${DISK}" ]
+then
+    echo "$0: '${DISK}' is not a block device" >&2
+    exit 1
+fi
+
+if [ -z "${ARCH}" ]
+then
+    export ARCH=x86_64
+fi
+
+if [ -z "${CONFIG_NAME}" ]
+then
+    export CONFIG_NAME=demo
+fi
+
+IMAGE="build/${ARCH}/${CONFIG_NAME}/harddrive.img"
+set -x
+make "${IMAGE}"
+sudo popsicle "${IMAGE}" "${DISK}"
+set +x
+
+ESP="$(bootctl --print-esp-path)"
+if [ -z "${ESP}" ]
+then
+    echo "$0: no ESP found" >&2
+    exit 1
+fi
+
+BOOTLOADER="cookbook/recipes/bootloader/target/${ARCH}-unknown-redox/stage/boot/bootloader.efi"
+set -x
+sudo mkdir -pv "${ESP}/EFI" "${ESP}/loader/entries"
+sudo cp -v "${BOOTLOADER}" "${ESP}/EFI/redox.efi"
+sudo tee "${ESP}/loader/entries/redox.conf" <<EOF
+title Redox OS
+efi /EFI/redox.efi
+EOF
+set +x
+
+sync