support/scripts/mkukimg: Add support for `EFI` Disk images

Begin by taking the setting up of the `EFI System Partition` layout
from `mkukefiiso` into a separate function `mkukefiesp`, since it
applies to any image involving an `EFI System Partition` with the
`Unikraft` `EFI` stub.

Next, create the usual disk image formatted with a `GPT` and a single
partition, that of the `EFI System Partition`, which has the same layout
as the `ISO` image.

Furthermore, clarify in the usage message that we now support disk
images for `ukefi` only and add the corresponding `OPTFORMAT` case.

To avoid ambiguity in the `OPTFORMAT` cases' messages, specify the
type of of bootloader that is not supported for the respective image
format.

Signed-off-by: Sergiu Moga <sergiu.moga@protonmail.com>
Reviewed-by: Stefan Jumarea <stefanjumarea02@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
Tested-by: Unikraft CI <monkey@unikraft.io>
GitHub-Closes: #910

diff --git a/support/scripts/mkukimg b/support/scripts/mkukimg
index 9f70598d13a32213443234fa25c41463997afe73..0177a529775b7ac1c050d13063848eecf3c0339f 100755 (executable)
--- a/support/scripts/mkukimg
+++ b/support/scripts/mkukimg
@@ -7,7 +7,7 @@ usage()
        echo "Creates bootable images from Unikraft kernel images."
        echo ""
        echo "  -h                         Display help and exit"
-       echo "  -f                         Output format (supported: iso)"
+       echo "  -f                         Output format: iso, disk (ukefi only)"
        echo "  -k                         Path to the Unikraft kernel image"
        echo "  -c                         Kernel command-line parameters file (optional)"
        echo "  -i                         Path to initrd cpio file (optional)"
@@ -69,40 +69,95 @@ EOF
        fi
 }
 
+# Helper function for mkukefi{iso,disk}
+# Given a directory, creates an EFI System Partition layout
+mkukefiesp()
+{
+       ESP=${1}
+       if [ -z "${ESP}" ]; then
+               echo "mkukefiesp() must receive the directory where the ESP is mounted"
+               exit 1
+       fi
+
+       sudo mkdir -p "${ESP}"/EFI/BOOT/
+
+       if [ -n "${OPTINITRD}" ]; then
+               sudo cp "${OPTINITRD}" "${ESP}/EFI/BOOT/"
+       fi
+
+       if [ -n "${OPTCMDLINE}" ]; then
+               sudo cp "${OPTCMDLINE}" "${ESP}/EFI/BOOT/"
+       fi
+
+       if [ -n "${OPTDTB}" ]; then
+               sudo cp "${OPTDTB}" "${ESP}/EFI/BOOT/"
+       fi
+
+       sudo cp "${OPTKERNELIMG}" "${ESP}/EFI/BOOT/BOOT${OPTARCH}.EFI"
+}
+
 mkukefiiso()
 {
        # create initial empty image we will format as FAT32
        # ESP must be at least 100MB
-       dd if=/dev/zero of=${BUILDDIR}/fs.img bs=1M count=100
+       dd if=/dev/zero of="${BUILDDIR}/fs.img" bs=1M count=100
 
-       mkfs.vfat -F 32 ${BUILDDIR}/fs.img
+       mkfs.vfat -F 32 "${BUILDDIR}/fs.img"
 
-       LOOPDEV=$(sudo losetup --find --show ${BUILDDIR}/fs.img)
-       mkdir ${BUILDDIR}/mnt
-       sudo mount ${LOOPDEV} ${BUILDDIR}/mnt
-       sudo mkdir -p ${BUILDDIR}/mnt/EFI/BOOT/
+       LOOPDEV=$(sudo losetup --find --show "${BUILDDIR}/fs.img")
+       mkdir "${BUILDDIR}/mnt"
+       sudo mount "${LOOPDEV}" "${BUILDDIR}/mnt"
 
-       if [ ! -z ${OPTINITRD} ]; then
-               sudo cp ${OPTINITRD} ${BUILDDIR}/mnt/EFI/BOOT/
-       fi
+       mkukefiesp "${BUILDDIR}/mnt"
 
-       if [ ! -z ${OPTCMDLINE} ]; then
-               sudo cp ${OPTCMDLINE} ${BUILDDIR}/mnt/EFI/BOOT/
-       fi
+       sudo umount "${BUILDDIR}/mnt"
+       sudo losetup -d "${LOOPDEV}"
 
-       if [ ! -z ${OPTDTB} ]; then
-               sudo cp ${OPTDTB} ${BUILDDIR}/mnt/EFI/BOOT/
-       fi
+       mkdir "${BUILDDIR}/iso_dir"
+       cp "${BUILDDIR}/fs.img" "${BUILDDIR}/iso_dir"
+       echo "${OPTOUTPUT}"
+       xorriso -as mkisofs -R -f -e fs.img -no-emul-boot -o "${OPTOUTPUT}" "${BUILDDIR}/iso_dir"
+}
+
+mkukefidisk()
+{
+       # create initial empty image we will format as GPT
+       # ESP must be at least 100MB and must be FAT12/16/32, but leave some
+       # room for the GPT and the backup GPT as well as the PMBR (5MB is enough)
+       dd if=/dev/zero of="${OPTOUTPUT}" bs=1M count=105
+
+       # Create the partition table
+       #       g\n     Create new GPT
+       #       n\n     Create new partition
+       #       1\n     Select partition number as 1
+       #       \n      Default first sector
+       #       \n      Default last sector
+       #       t\n     Change type of partition (default partition 1)
+       #       1\n     Mark partition 1 as EFI System Partition
+       #       w\n     Write the changes to the disk image
+       echo -e "                                                               \
+               g\n                                                             \
+               n\n                                                             \
+               1\n                                                             \
+               \n                                                              \
+               \n                                                              \
+               t\n                                                             \
+               1\n                                                             \
+               w\n                                                             \
+               " | fdisk -W always "${OPTOUTPUT}"      # Wipe filesystem, RAID \
+                                                       # and partition-table signatures
 
-       sudo cp ${OPTKERNELIMG} ${BUILDDIR}/mnt/EFI/BOOT/BOOT${OPTARCH}.EFI
+       LOOPDEV=$(sudo losetup --find --show "${OPTOUTPUT}")
+       sudo partprobe "${LOOPDEV}"
+       sudo mkfs.vfat -F 32 "${LOOPDEV}p1"
 
-       sudo umount ${BUILDDIR}/mnt
-       sudo losetup -d ${LOOPDEV}
+       mkdir "${BUILDDIR}/mnt"
+       sudo mount "${LOOPDEV}p1" "${BUILDDIR}/mnt"     # We only have one partition
 
-       mkdir ${BUILDDIR}/iso_dir
-       cp ${BUILDDIR}/fs.img ${BUILDDIR}/iso_dir
-       echo ${OPTOUTPUT}
-       xorriso -as mkisofs -R -f -e fs.img -no-emul-boot -o ${OPTOUTPUT} ${BUILDDIR}/iso_dir
+       mkukefiesp "${BUILDDIR}/mnt"
+
+       sudo umount "${BUILDDIR}/mnt"
+       sudo losetup -d "${LOOPDEV}"
 }
 
 # process options
@@ -185,7 +240,18 @@ case "${OPTFORMAT}" in
                        mkukefiiso
                        ;;
                *)
-                       echo -e "\"${OPTBOOTLOADER}\" not a supported bootloader." 1>&2
+                       echo -e "\"${OPTBOOTLOADER}\" not a supported bootloader for ISO images." 1>&2
+                       usage
+                       ;;
+               esac
+               ;;
+       disk)
+               case "${OPTBOOTLOADER}" in
+               ukefi)
+                       mkukefidisk
+                       ;;
+               *)
+                       echo -e "\"${OPTBOOTLOADER}\" not a supported bootloader for DISK images." 1>&2
                        usage
                        ;;
                esac