Add new export (image) with a swap partition

Demo the new custom export capability with an new export type
'export-swappart-image' that uses a swap partition.  Note that it really
only makes sense if one tweaks stage2 to not include dphys-swapfile.

Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>

config-swappart.example

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+#!/bin/bash -e
+
+export IMG_NAME="swapport-test"
+export stage2_EXPORT_LIST="export-swappart-image export-image export-noobs"
+export stage4_EXPORT_LIST="export-swappart-image export-image export-noobs"
+export stage5_EXPORT_LIST="export-swappart-image export-image export-noobs"
+# 2GB Swap
+export SWAP_SIZE=$(( 2048 * 1024 * 1024))

export-swappart-image/00-allow-rerun

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+../export-image/00-allow-rerun

export-swappart-image/01-set-sources

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+../export-image/01-set-sources

export-swappart-image/02-network

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+../export-image/02-network

export-swappart-image/03-set-partuuid/00-run.sh

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+#!/bin/bash -e
+
+IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
+
+IMGID="$(dd if="${IMG_FILE}" skip=440 bs=1 count=4 2>/dev/null | xxd -e | cut -f 2 -d' ')"
+
+BOOT_PARTUUID="${IMGID}-01"
+SWAP_PARTUUID="${IMGID}-02"
+ROOT_PARTUUID="${IMGID}-03"
+
+install -m 0644 files/fstab "${ROOTFS_DIR}/etc/fstab"
+sed -i "s/BOOTDEV/PARTUUID=${BOOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+sed -i "s/SWAPDEV/PARTUUID=${SWAP_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/etc/fstab"
+
+sed -i "s/ROOTDEV/PARTUUID=${ROOT_PARTUUID}/" "${ROOTFS_DIR}/boot/cmdline.txt"

export-swappart-image/03-set-partuuid/files/fstab

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+proc            /proc           proc    defaults          0       0
+BOOTDEV  /boot           vfat    defaults          0       2
+ROOTDEV  /               ext4    defaults,noatime  0       1
+SWAPDEV  none            swap    sw                0       0

export-swappart-image/04-finalise

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+../export-image/04-finalise

export-swappart-image/prerun.sh

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+#!/bin/bash -e
+
+IMG_FILE="${STAGE_WORK_DIR}/${IMG_FILENAME}${IMG_SUFFIX}.img"
+
+unmount_image "${IMG_FILE}"
+
+rm -f "${IMG_FILE}"
+
+rm -rf "${ROOTFS_DIR}"
+mkdir -p "${ROOTFS_DIR}"
+
+BOOT_SIZE="$((256 * 1024 * 1024))"
+SWAP_SIZE="${SWAP_SIZE:-$((1024 * 1024 * 1024))}"
+ROOT_SIZE=$(du --apparent-size -s "${EXPORT_ROOTFS_DIR}" --exclude var/cache/apt/archives --exclude boot --block-size=1 | cut -f 1)
+
+# All partition sizes and starts will be aligned to this size
+ALIGN="$((4 * 1024 * 1024))"
+# Add this much space to the calculated file size. This allows for
+# some overhead (since actual space usage is usually rounded up to the
+# filesystem block size) and gives some free space on the resulting
+# image.
+ROOT_MARGIN=$((800*1024*1024))
+
+BOOT_PART_START=$((ALIGN))
+BOOT_PART_SIZE=$(((BOOT_SIZE + ALIGN - 1) / ALIGN * ALIGN))
+SWAP_PART_START=$((BOOT_PART_START + BOOT_PART_SIZE))
+SWAP_PART_SIZE=$(((SWAP_SIZE + ALIGN  - 1) / ALIGN * ALIGN))
+ROOT_PART_START=$((SWAP_PART_START + SWAP_PART_SIZE))
+ROOT_PART_SIZE=$(((ROOT_SIZE + ROOT_MARGIN + ALIGN  - 1) / ALIGN * ALIGN))
+IMG_SIZE=$((BOOT_PART_START + BOOT_PART_SIZE + SWAP_PART_SIZE + ROOT_PART_SIZE))
+
+truncate -s "${IMG_SIZE}" "${IMG_FILE}"
+
+parted --script "${IMG_FILE}" mklabel msdos
+parted --script "${IMG_FILE}" unit B mkpart primary fat32 "${BOOT_PART_START}" "$((BOOT_PART_START + BOOT_PART_SIZE - 1))"
+parted --script "${IMG_FILE}" unit B mkpart primary linux-swap "${SWAP_PART_START}" "$((SWAP_PART_START + SWAP_PART_SIZE - 1))"
+parted --script "${IMG_FILE}" unit B mkpart primary ext4 "${ROOT_PART_START}" "$((ROOT_PART_START + ROOT_PART_SIZE - 1))"
+
+PARTED_OUT=$(parted -sm "${IMG_FILE}" unit b print)
+BOOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 2 | tr -d B)
+BOOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^1:' | cut -d':' -f 4 | tr -d B)
+
+SWAP_OFFSET=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 2 | tr -d B)
+SWAP_LENGTH=$(echo "$PARTED_OUT" | grep -e '^2:' | cut -d':' -f 4 | tr -d B)
+
+ROOT_OFFSET=$(echo "$PARTED_OUT" | grep -e '^3:' | cut -d':' -f 2 | tr -d B)
+ROOT_LENGTH=$(echo "$PARTED_OUT" | grep -e '^3:' | cut -d':' -f 4 | tr -d B)
+
+BOOT_DEV=$(losetup --show -f -o "${BOOT_OFFSET}" --sizelimit "${BOOT_LENGTH}" "${IMG_FILE}")
+SWAP_DEV=$(losetup --show -f -o "${SWAP_OFFSET}" --sizelimit "${SWAP_LENGTH}" "${IMG_FILE}")
+ROOT_DEV=$(losetup --show -f -o "${ROOT_OFFSET}" --sizelimit "${ROOT_LENGTH}" "${IMG_FILE}")
+echo "/boot: offset $BOOT_OFFSET, length $BOOT_LENGTH"
+echo "swap:  offset $SWAP_OFFSET, length $SWAP_LENGTH"
+echo "/:     offset $ROOT_OFFSET, length $ROOT_LENGTH"
+
+ROOT_FEATURES="^huge_file"
+for FEATURE in metadata_csum 64bit; do
+	if grep -q "$FEATURE" /etc/mke2fs.conf; then
+	    ROOT_FEATURES="^$FEATURE,$ROOT_FEATURES"
+	fi
+done
+mkdosfs -n boot -F 32 -v "$BOOT_DEV" > /dev/null
+mkswap "$SWAP_DEV" >/dev/null
+mkfs.ext4 -L rootfs -O "$ROOT_FEATURES" "$ROOT_DEV" > /dev/null
+
+mount -v "$ROOT_DEV" "${ROOTFS_DIR}" -t ext4
+mkdir -p "${ROOTFS_DIR}/boot"
+mount -v "$BOOT_DEV" "${ROOTFS_DIR}/boot" -t vfat
+
+rsync -aHAXx --exclude /var/cache/apt/archives --exclude /boot "${EXPORT_ROOTFS_DIR}/" "${ROOTFS_DIR}/"
+rsync -rtx "${EXPORT_ROOTFS_DIR}/boot/" "${ROOTFS_DIR}/boot/"

stage2/EXPORT_SWAPPART_IMAGE

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+IMG_SUFFIX="-swap-lite"
+if [ "${USE_QEMU}" = "1" ]; then
+	export IMG_SUFFIX="${IMG_SUFFIX}-qemu"
+fi