poky/meta/classes-recipe/kernel-fitimage.bbclass

#
# Copyright OpenEmbedded Contributors
#
# SPDX-License-Identifier: MIT
#

inherit kernel-uboot kernel-artifact-names uboot-config

def get_fit_replacement_type(d):
    kerneltypes = d.getVar('KERNEL_IMAGETYPES') or ""
    replacementtype = ""
    if 'fitImage' in kerneltypes.split():
        uarch = d.getVar("UBOOT_ARCH")
        if uarch == "arm64":
            replacementtype = "Image"
        elif uarch == "riscv":
            replacementtype = "Image"
        elif uarch == "mips":
            replacementtype = "vmlinuz.bin"
        elif uarch == "x86":
            replacementtype = "bzImage"
        elif uarch == "microblaze":
            replacementtype = "linux.bin"
        else:
            replacementtype = "zImage"
    return replacementtype

KERNEL_IMAGETYPE_REPLACEMENT ?= "${@get_fit_replacement_type(d)}"
DEPENDS:append = " ${@'u-boot-tools-native dtc-native' if 'fitImage' in (d.getVar('KERNEL_IMAGETYPES') or '').split() else ''}"

python __anonymous () {
        # Override KERNEL_IMAGETYPE_FOR_MAKE variable, which is internal
        # to kernel.bbclass . We have to override it, since we pack zImage
        # (at least for now) into the fitImage .
        typeformake = d.getVar("KERNEL_IMAGETYPE_FOR_MAKE") or ""
        if 'fitImage' in typeformake.split():
            d.setVar('KERNEL_IMAGETYPE_FOR_MAKE', typeformake.replace('fitImage', d.getVar('KERNEL_IMAGETYPE_REPLACEMENT')))

        image = d.getVar('INITRAMFS_IMAGE')
        if image:
            d.appendVarFlag('do_assemble_fitimage_initramfs', 'depends', ' ${INITRAMFS_IMAGE}:do_image_complete')

        ubootenv = d.getVar('UBOOT_ENV')
        if ubootenv:
            d.appendVarFlag('do_assemble_fitimage', 'depends', ' virtual/bootloader:do_populate_sysroot')

        #check if there are any dtb providers
        providerdtb = d.getVar("PREFERRED_PROVIDER_virtual/dtb")
        if providerdtb:
            d.appendVarFlag('do_assemble_fitimage', 'depends', ' virtual/dtb:do_populate_sysroot')
            d.appendVarFlag('do_assemble_fitimage_initramfs', 'depends', ' virtual/dtb:do_populate_sysroot')
            d.setVar('EXTERNAL_KERNEL_DEVICETREE', "${RECIPE_SYSROOT}/boot/devicetree")
}


# Description string
FIT_DESC ?= "Kernel fitImage for ${DISTRO_NAME}/${PV}/${MACHINE}"

# Kernel fitImage Hash Algo
FIT_HASH_ALG ?= "sha256"

# Kernel fitImage Signature Algo
FIT_SIGN_ALG ?= "rsa2048"

# Kernel / U-Boot fitImage Padding Algo
FIT_PAD_ALG ?= "pkcs-1.5"

# Generate keys for signing Kernel fitImage
FIT_GENERATE_KEYS ?= "0"

# Size of private keys in number of bits
FIT_SIGN_NUMBITS ?= "2048"

# args to openssl genrsa (Default is just the public exponent)
FIT_KEY_GENRSA_ARGS ?= "-F4"

# args to openssl req (Default is -batch for non interactive mode and
# -new for new certificate)
FIT_KEY_REQ_ARGS ?= "-batch -new"

# Standard format for public key certificate
FIT_KEY_SIGN_PKCS ?= "-x509"

# Sign individual images as well
FIT_SIGN_INDIVIDUAL ?= "0"

FIT_CONF_PREFIX ?= "conf-"
FIT_CONF_PREFIX[doc] = "Prefix to use for FIT configuration node name"

FIT_SUPPORTED_INITRAMFS_FSTYPES ?= "cpio.lz4 cpio.lzo cpio.lzma cpio.xz cpio.zst cpio.gz ext2.gz cpio"

# Allow user to select the default DTB for FIT image when multiple dtb's exists.
FIT_CONF_DEFAULT_DTB ?= ""

# length of address in number of <u32> cells
# ex: 1 32bits address, 2 64bits address
FIT_ADDRESS_CELLS ?= "1"

# Keys used to sign individually image nodes.
# The keys to sign image nodes must be different from those used to sign
# configuration nodes, otherwise the "required" property, from
# UBOOT_DTB_BINARY, will be set to "conf", because "conf" prevails on "image".
# Then the images signature checking will not be mandatory and no error will be
# raised in case of failure.
# UBOOT_SIGN_IMG_KEYNAME = "dev2" # keys name in keydir (eg. "dev2.crt", "dev2.key")

#
# Emit the fitImage ITS header
#
# $1 ... .its filename
fitimage_emit_fit_header() {
	cat << EOF >> $1
/dts-v1/;

/ {
        description = "${FIT_DESC}";
        #address-cells = <${FIT_ADDRESS_CELLS}>;
EOF
}

#
# Emit the fitImage section bits
#
# $1 ... .its filename
# $2 ... Section bit type: imagestart - image section start
#                          confstart  - configuration section start
#                          sectend    - section end
#                          fitend     - fitimage end
#
fitimage_emit_section_maint() {
	case $2 in
	imagestart)
		cat << EOF >> $1

        images {
EOF
	;;
	confstart)
		cat << EOF >> $1

        configurations {
EOF
	;;
	sectend)
		cat << EOF >> $1
	};
EOF
	;;
	fitend)
		cat << EOF >> $1
};
EOF
	;;
	esac
}

#
# Emit the fitImage ITS kernel section
#
# $1 ... .its filename
# $2 ... Image counter
# $3 ... Path to kernel image
# $4 ... Compression type
fitimage_emit_section_kernel() {

	kernel_csum="${FIT_HASH_ALG}"
	kernel_sign_algo="${FIT_SIGN_ALG}"
	kernel_sign_keyname="${UBOOT_SIGN_IMG_KEYNAME}"

	ENTRYPOINT="${UBOOT_ENTRYPOINT}"
	if [ -n "${UBOOT_ENTRYSYMBOL}" ]; then
		ENTRYPOINT=`${HOST_PREFIX}nm vmlinux | \
			awk '$3=="${UBOOT_ENTRYSYMBOL}" {print "0x"$1;exit}'`
	fi

	cat << EOF >> $1
                kernel-$2 {
                        description = "Linux kernel";
                        data = /incbin/("$3");
                        type = "${UBOOT_MKIMAGE_KERNEL_TYPE}";
                        arch = "${UBOOT_ARCH}";
                        os = "linux";
                        compression = "$4";
                        load = <${UBOOT_LOADADDRESS}>;
                        entry = <$ENTRYPOINT>;
                        hash-1 {
                                algo = "$kernel_csum";
                        };
                };
EOF

	if [ "${UBOOT_SIGN_ENABLE}" = "1" -a "${FIT_SIGN_INDIVIDUAL}" = "1" -a -n "$kernel_sign_keyname" ] ; then
		sed -i '$ d' $1
		cat << EOF >> $1
                        signature-1 {
                                algo = "$kernel_csum,$kernel_sign_algo";
                                key-name-hint = "$kernel_sign_keyname";
                        };
                };
EOF
	fi
}

#
# Emit the fitImage ITS DTB section
#
# $1 ... .its filename
# $2 ... Image counter
# $3 ... Path to DTB image
fitimage_emit_section_dtb() {

	dtb_csum="${FIT_HASH_ALG}"
	dtb_sign_algo="${FIT_SIGN_ALG}"
	dtb_sign_keyname="${UBOOT_SIGN_IMG_KEYNAME}"

	dtb_loadline=""
	dtb_ext=${DTB##*.}
	if [ "${dtb_ext}" = "dtbo" ]; then
		if [ -n "${UBOOT_DTBO_LOADADDRESS}" ]; then
			dtb_loadline="load = <${UBOOT_DTBO_LOADADDRESS}>;"
		fi
	elif [ -n "${UBOOT_DTB_LOADADDRESS}" ]; then
		dtb_loadline="load = <${UBOOT_DTB_LOADADDRESS}>;"
	fi
	cat << EOF >> $1
                fdt-$2 {
                        description = "Flattened Device Tree blob";
                        data = /incbin/("$3");
                        type = "flat_dt";
                        arch = "${UBOOT_ARCH}";
                        compression = "none";
                        $dtb_loadline
                        hash-1 {
                                algo = "$dtb_csum";
                        };
                };
EOF

	if [ "${UBOOT_SIGN_ENABLE}" = "1" -a "${FIT_SIGN_INDIVIDUAL}" = "1" -a -n "$dtb_sign_keyname" ] ; then
		sed -i '$ d' $1
		cat << EOF >> $1
                        signature-1 {
                                algo = "$dtb_csum,$dtb_sign_algo";
                                key-name-hint = "$dtb_sign_keyname";
                        };
                };
EOF
	fi
}

#
# Emit the fitImage ITS u-boot script section
#
# $1 ... .its filename
# $2 ... Image counter
# $3 ... Path to boot script image
fitimage_emit_section_boot_script() {

	bootscr_csum="${FIT_HASH_ALG}"
	bootscr_sign_algo="${FIT_SIGN_ALG}"
	bootscr_sign_keyname="${UBOOT_SIGN_IMG_KEYNAME}"

        cat << EOF >> $1
                bootscr-$2 {
                        description = "U-boot script";
                        data = /incbin/("$3");
                        type = "script";
                        arch = "${UBOOT_ARCH}";
                        compression = "none";
                        hash-1 {
                                algo = "$bootscr_csum";
                        };
                };
EOF

	if [ "${UBOOT_SIGN_ENABLE}" = "1" -a "${FIT_SIGN_INDIVIDUAL}" = "1" -a -n "$bootscr_sign_keyname" ] ; then
		sed -i '$ d' $1
		cat << EOF >> $1
                        signature-1 {
                                algo = "$bootscr_csum,$bootscr_sign_algo";
                                key-name-hint = "$bootscr_sign_keyname";
                        };
                };
EOF
	fi
}

#
# Emit the fitImage ITS setup section
#
# $1 ... .its filename
# $2 ... Image counter
# $3 ... Path to setup image
fitimage_emit_section_setup() {

	setup_csum="${FIT_HASH_ALG}"

	cat << EOF >> $1
                setup-$2 {
                        description = "Linux setup.bin";
                        data = /incbin/("$3");
                        type = "x86_setup";
                        arch = "${UBOOT_ARCH}";
                        os = "linux";
                        compression = "none";
                        load = <0x00090000>;
                        entry = <0x00090000>;
                        hash-1 {
                                algo = "$setup_csum";
                        };
                };
EOF
}

#
# Emit the fitImage ITS ramdisk section
#
# $1 ... .its filename
# $2 ... Image counter
# $3 ... Path to ramdisk image
fitimage_emit_section_ramdisk() {

	ramdisk_csum="${FIT_HASH_ALG}"
	ramdisk_sign_algo="${FIT_SIGN_ALG}"
	ramdisk_sign_keyname="${UBOOT_SIGN_IMG_KEYNAME}"
	ramdisk_loadline=""
	ramdisk_entryline=""

	if [ -n "${UBOOT_RD_LOADADDRESS}" ]; then
		ramdisk_loadline="load = <${UBOOT_RD_LOADADDRESS}>;"
	fi
	if [ -n "${UBOOT_RD_ENTRYPOINT}" ]; then
		ramdisk_entryline="entry = <${UBOOT_RD_ENTRYPOINT}>;"
	fi

	cat << EOF >> $1
                ramdisk-$2 {
                        description = "${INITRAMFS_IMAGE}";
                        data = /incbin/("$3");
                        type = "ramdisk";
                        arch = "${UBOOT_ARCH}";
                        os = "linux";
                        compression = "none";
                        $ramdisk_loadline
                        $ramdisk_entryline
                        hash-1 {
                                algo = "$ramdisk_csum";
                        };
                };
EOF

	if [ "${UBOOT_SIGN_ENABLE}" = "1" -a "${FIT_SIGN_INDIVIDUAL}" = "1" -a -n "$ramdisk_sign_keyname" ] ; then
		sed -i '$ d' $1
		cat << EOF >> $1
                        signature-1 {
                                algo = "$ramdisk_csum,$ramdisk_sign_algo";
                                key-name-hint = "$ramdisk_sign_keyname";
                        };
                };
EOF
	fi
}

#
# echoes symlink destination if it points below directory
#
# $1 ... file that's a potential symlink
# $2 ... expected parent directory
symlink_points_below() {
	file="$2/$1"
	dir=$2

	if ! [ -L "$file" ]; then
		return
	fi

	realpath="$(realpath --relative-to=$dir $file)"
	if [ -z "${realpath%%../*}" ]; then
		return
	fi

	echo "$realpath"
}

#
# Emit the fitImage ITS configuration section
#
# $1 ... .its filename
# $2 ... Linux kernel ID
# $3 ... DTB image name
# $4 ... ramdisk ID
# $5 ... u-boot script ID
# $6 ... config ID
# $7 ... default flag
# $8 ... default DTB image name
fitimage_emit_section_config() {

	conf_csum="${FIT_HASH_ALG}"
	conf_sign_algo="${FIT_SIGN_ALG}"
	conf_padding_algo="${FIT_PAD_ALG}"
	if [ "${UBOOT_SIGN_ENABLE}" = "1" ] ; then
		conf_sign_keyname="${UBOOT_SIGN_KEYNAME}"
	fi

	its_file="$1"
	kernel_id="$2"
	dtb_image="$3"
	ramdisk_id="$4"
	bootscr_id="$5"
	config_id="$6"
	default_flag="$7"
	default_dtb_image="$8"

	# Test if we have any DTBs at all
	sep=""
	conf_desc=""
	conf_node="${FIT_CONF_PREFIX}"
	kernel_line=""
	fdt_line=""
	ramdisk_line=""
	bootscr_line=""
	setup_line=""
	default_line=""
	compatible_line=""

	dtb_image_sect=$(symlink_points_below $dtb_image "${EXTERNAL_KERNEL_DEVICETREE}")
	if [ -z "$dtb_image_sect" ]; then
		dtb_image_sect=$dtb_image
	fi

	dtb_path="${EXTERNAL_KERNEL_DEVICETREE}/${dtb_image_sect}"
	if [ -e "$dtb_path" ]; then
		compat=$(fdtget -t s "$dtb_path" / compatible | sed 's/ /", "/g')
		if [ -n "$compat" ]; then
			compatible_line="compatible = \"$compat\";"
		fi
	fi

	dtb_image=$(echo $dtb_image | tr '/' '_')
	dtb_image_sect=$(echo "${dtb_image_sect}" | tr '/' '_')

	# conf node name is selected based on dtb ID if it is present,
	# otherwise its selected based on kernel ID
	if [ -n "$dtb_image" ]; then
		conf_node=$conf_node$dtb_image
	else
		conf_node=$conf_node$kernel_id
	fi

	if [ -n "$kernel_id" ]; then
		conf_desc="Linux kernel"
		sep=", "
		kernel_line="kernel = \"kernel-$kernel_id\";"
	fi

	if [ -n "$dtb_image" ]; then
		conf_desc="$conf_desc${sep}FDT blob"
		sep=", "
		fdt_line="fdt = \"fdt-$dtb_image_sect\";"
	fi

	if [ -n "$ramdisk_id" ]; then
		conf_desc="$conf_desc${sep}ramdisk"
		sep=", "
		ramdisk_line="ramdisk = \"ramdisk-$ramdisk_id\";"
	fi

	if [ -n "$bootscr_id" ]; then
		conf_desc="$conf_desc${sep}u-boot script"
		sep=", "
		bootscr_line="bootscr = \"bootscr-$bootscr_id\";"
	fi

	if [ -n "$config_id" ]; then
		conf_desc="$conf_desc${sep}setup"
		setup_line="setup = \"setup-$config_id\";"
	fi

	if [ "$default_flag" = "1" ]; then
		# default node is selected based on dtb ID if it is present,
		# otherwise its selected based on kernel ID
		if [ -n "$dtb_image" ]; then
		        # Select default node as user specified dtb when
		        # multiple dtb exists.
		        if [ -n "$default_dtb_image" ]; then
			        default_line="default = \"${FIT_CONF_PREFIX}$default_dtb_image\";"
		        else
			        default_line="default = \"${FIT_CONF_PREFIX}$dtb_image\";"
		        fi
		else
			default_line="default = \"${FIT_CONF_PREFIX}$kernel_id\";"
		fi
	fi

	cat << EOF >> $its_file
                $default_line
                $conf_node {
                        description = "$default_flag $conf_desc";
                        $compatible_line
                        $kernel_line
                        $fdt_line
                        $ramdisk_line
                        $bootscr_line
                        $setup_line
                        hash-1 {
                                algo = "$conf_csum";
                        };
EOF

	if [ -n "$conf_sign_keyname" ] ; then

		sign_line="sign-images = "
		sep=""

		if [ -n "$kernel_id" ]; then
			sign_line="$sign_line${sep}\"kernel\""
			sep=", "
		fi

		if [ -n "$dtb_image" ]; then
			sign_line="$sign_line${sep}\"fdt\""
			sep=", "
		fi

		if [ -n "$ramdisk_id" ]; then
			sign_line="$sign_line${sep}\"ramdisk\""
			sep=", "
		fi

		if [ -n "$bootscr_id" ]; then
			sign_line="$sign_line${sep}\"bootscr\""
			sep=", "
		fi

		if [ -n "$config_id" ]; then
			sign_line="$sign_line${sep}\"setup\""
		fi

		sign_line="$sign_line;"

		cat << EOF >> $its_file
                        signature-1 {
                                algo = "$conf_csum,$conf_sign_algo";
                                key-name-hint = "$conf_sign_keyname";
                                padding = "$conf_padding_algo";
                                $sign_line
                        };
EOF
	fi

	cat << EOF >> $its_file
                };
EOF
}

#
# Assemble fitImage
#
# $1 ... .its filename
# $2 ... fitImage name
# $3 ... include ramdisk
fitimage_assemble() {
	kernelcount=1
	dtbcount=""
	DTBS=""
	ramdiskcount=$3
	setupcount=""
	bootscr_id=""
	default_dtb_image=""
	rm -f $1 arch/${ARCH}/boot/$2

	if [ -n "${UBOOT_SIGN_IMG_KEYNAME}" -a "${UBOOT_SIGN_KEYNAME}" = "${UBOOT_SIGN_IMG_KEYNAME}" ]; then
		bbfatal "Keys used to sign images and configuration nodes must be different."
	fi

	fitimage_emit_fit_header $1

	#
	# Step 1: Prepare a kernel image section.
	#
	fitimage_emit_section_maint $1 imagestart

	uboot_prep_kimage
	fitimage_emit_section_kernel $1 $kernelcount linux.bin "$linux_comp"

	#
	# Step 2: Prepare a DTB image section
	#

	if [ -n "${KERNEL_DEVICETREE}" ]; then
		dtbcount=1
		for DTB in ${KERNEL_DEVICETREE}; do
			if echo $DTB | grep -q '/dts/'; then
				bbwarn "$DTB contains the full path to the the dts file, but only the dtb name should be used."
				DTB=`basename $DTB | sed 's,\.dts$,.dtb,g'`
			fi

			# Skip ${DTB} if it's also provided in ${EXTERNAL_KERNEL_DEVICETREE}
			if [ -n "${EXTERNAL_KERNEL_DEVICETREE}" ] && [ -s ${EXTERNAL_KERNEL_DEVICETREE}/${DTB} ]; then
				continue
			fi

			DTB_PATH="${KERNEL_OUTPUT_DIR}/dts/$DTB"
			if [ ! -e "$DTB_PATH" ]; then
				DTB_PATH="${KERNEL_OUTPUT_DIR}/$DTB"
			fi

		        # Strip off the path component from the filename
			if "${@'false' if oe.types.boolean(d.getVar('KERNEL_DTBVENDORED')) else 'true'}"; then
			    DTB=`basename $DTB`
			fi

			# Set the default dtb image if it exists in the devicetree.
			if [ ${FIT_CONF_DEFAULT_DTB} = $DTB ];then
				default_dtb_image=$(echo "$DTB" | tr '/' '_')
			fi

			DTB=$(echo "$DTB" | tr '/' '_')

			# Skip DTB if we've picked it up previously
			echo "$DTBS" | tr ' ' '\n' | grep -xq "$DTB" && continue

			DTBS="$DTBS $DTB"
			DTB=$(echo $DTB | tr '/' '_')
			fitimage_emit_section_dtb $1 $DTB $DTB_PATH
		done
	fi

	if [ -n "${EXTERNAL_KERNEL_DEVICETREE}" ]; then
		dtbcount=1
		for DTB in $(find "${EXTERNAL_KERNEL_DEVICETREE}" -name '*.dtb' -printf '%P\n' | sort) \
		$(find "${EXTERNAL_KERNEL_DEVICETREE}" -name '*.dtbo' -printf '%P\n' | sort); do
			# Set the default dtb image if it exists in the devicetree.
			if [ ${FIT_CONF_DEFAULT_DTB} = $DTB ];then
				default_dtb_image=$(echo "$DTB" | tr '/' '_')
			fi

			DTB=$(echo "$DTB" | tr '/' '_')

			# Skip DTB/DTBO if we've picked it up previously
			echo "$DTBS" | tr ' ' '\n' | grep -xq "$DTB" && continue

			DTBS="$DTBS $DTB"

			# Also skip if a symlink. We'll later have each config section point at it
			[ $(symlink_points_below $DTB "${EXTERNAL_KERNEL_DEVICETREE}") ] && continue

			DTB=$(echo $DTB | tr '/' '_')
			fitimage_emit_section_dtb $1 $DTB "${EXTERNAL_KERNEL_DEVICETREE}/$DTB"
		done
	fi

	if [ -n "${FIT_CONF_DEFAULT_DTB}" ] && [ -z $default_dtb_image ]; then 
		bbwarn "${FIT_CONF_DEFAULT_DTB} is not available in the list of device trees."
	fi

	#
	# Step 3: Prepare a u-boot script section
	#

	if [ -n "${UBOOT_ENV}" ] && [ -d "${STAGING_DIR_HOST}/boot" ]; then
		if [ -e "${STAGING_DIR_HOST}/boot/${UBOOT_ENV_BINARY}" ]; then
			cp ${STAGING_DIR_HOST}/boot/${UBOOT_ENV_BINARY} ${B}
			bootscr_id="${UBOOT_ENV_BINARY}"
			fitimage_emit_section_boot_script $1 "$bootscr_id" ${UBOOT_ENV_BINARY}
		else
			bbwarn "${STAGING_DIR_HOST}/boot/${UBOOT_ENV_BINARY} not found."
		fi
	fi

	#
	# Step 4: Prepare a setup section. (For x86)
	#
	if [ -e ${KERNEL_OUTPUT_DIR}/setup.bin ]; then
		setupcount=1
		fitimage_emit_section_setup $1 $setupcount ${KERNEL_OUTPUT_DIR}/setup.bin
	fi

	#
	# Step 5: Prepare a ramdisk section.
	#
	if [ "x${ramdiskcount}" = "x1" ] && [ "${INITRAMFS_IMAGE_BUNDLE}" != "1" ]; then
		# Find and use the first initramfs image archive type we find
		found=
		for img in ${FIT_SUPPORTED_INITRAMFS_FSTYPES}; do
			initramfs_path="${DEPLOY_DIR_IMAGE}/${INITRAMFS_IMAGE_NAME}.$img"
			if [ -e "$initramfs_path" ]; then
				bbnote "Found initramfs image: $initramfs_path"
				found=true
				fitimage_emit_section_ramdisk $1 "$ramdiskcount" "$initramfs_path"
				break
			else
				bbnote "Did not find initramfs image: $initramfs_path"
			fi
		done

		if [ -z "$found" ]; then
			bbfatal "Could not find a valid initramfs type for ${INITRAMFS_IMAGE_NAME}, the supported types are: ${FIT_SUPPORTED_INITRAMFS_FSTYPES}"
		fi
	fi

	fitimage_emit_section_maint $1 sectend

	# Force the first Kernel and DTB in the default config
	kernelcount=1
	if [ -n "$dtbcount" ]; then
		dtbcount=1
	fi

	#
	# Step 6: Prepare a configurations section
	#
	fitimage_emit_section_maint $1 confstart

	# kernel-fitimage.bbclass currently only supports a single kernel (no less or
	# more) to be added to the FIT image along with 0 or more device trees and
	# 0 or 1 ramdisk.
        # It is also possible to include an initramfs bundle (kernel and rootfs in one binary)
        # When the initramfs bundle is used ramdisk is disabled.
	# If a device tree is to be part of the FIT image, then select
	# the default configuration to be used is based on the dtbcount. If there is
	# no dtb present than select the default configuation to be based on
	# the kernelcount.
	if [ -n "$DTBS" ]; then
		i=1
		for DTB in ${DTBS}; do
			dtb_ext=${DTB##*.}
			if [ "$dtb_ext" = "dtbo" ]; then
				fitimage_emit_section_config $1 "" "$DTB" "" "$bootscr_id" "" "`expr $i = $dtbcount`" "$default_dtb_image"
			else
				fitimage_emit_section_config $1 $kernelcount "$DTB" "$ramdiskcount" "$bootscr_id" "$setupcount" "`expr $i = $dtbcount`" "$default_dtb_image"
			fi
			i=`expr $i + 1`
		done
	else
		defaultconfigcount=1
		fitimage_emit_section_config $1 $kernelcount "" "$ramdiskcount" "$bootscr_id"  "$setupcount" $defaultconfigcount "$default_dtb_image"
	fi

	fitimage_emit_section_maint $1 sectend

	fitimage_emit_section_maint $1 fitend

	#
	# Step 7: Assemble the image
	#
	${UBOOT_MKIMAGE} \
		${@'-D "${UBOOT_MKIMAGE_DTCOPTS}"' if len('${UBOOT_MKIMAGE_DTCOPTS}') else ''} \
		-f $1 \
		${KERNEL_OUTPUT_DIR}/$2

	#
	# Step 8: Sign the image
	#
	if [ "x${UBOOT_SIGN_ENABLE}" = "x1" ] ; then
		${UBOOT_MKIMAGE_SIGN} \
			${@'-D "${UBOOT_MKIMAGE_DTCOPTS}"' if len('${UBOOT_MKIMAGE_DTCOPTS}') else ''} \
			-F -k "${UBOOT_SIGN_KEYDIR}" \
			-r ${KERNEL_OUTPUT_DIR}/$2 \
			${UBOOT_MKIMAGE_SIGN_ARGS}
	fi
}

do_assemble_fitimage() {
	if echo ${KERNEL_IMAGETYPES} | grep -wq "fitImage"; then
		cd ${B}
		fitimage_assemble fit-image.its fitImage-none ""
		if [ "${INITRAMFS_IMAGE_BUNDLE}" != "1" ]; then
			ln -sf fitImage-none ${B}/${KERNEL_OUTPUT_DIR}/fitImage
		fi
	fi
}

addtask assemble_fitimage before do_install after do_compile

SYSROOT_DIRS:append = " /sysroot-only"
do_install:append() {
	if echo ${KERNEL_IMAGETYPES} | grep -wq "fitImage" && \
		[ "${UBOOT_SIGN_ENABLE}" = "1" ]; then
		install -D ${B}/${KERNEL_OUTPUT_DIR}/fitImage-none ${D}/sysroot-only/fitImage
	fi
}

do_assemble_fitimage_initramfs() {
	if echo ${KERNEL_IMAGETYPES} | grep -wq "fitImage" && \
		test -n "${INITRAMFS_IMAGE}" ; then
		cd ${B}
		if [ "${INITRAMFS_IMAGE_BUNDLE}" = "1" ]; then
			fitimage_assemble fit-image-${INITRAMFS_IMAGE}.its fitImage-bundle ""
			ln -sf fitImage-bundle ${B}/${KERNEL_OUTPUT_DIR}/fitImage
		else
			fitimage_assemble fit-image-${INITRAMFS_IMAGE}.its fitImage-${INITRAMFS_IMAGE} 1
		fi
	fi
}

addtask assemble_fitimage_initramfs before do_deploy after do_bundle_initramfs

do_kernel_generate_rsa_keys() {
	if [ "${UBOOT_SIGN_ENABLE}" = "0" ] && [ "${FIT_GENERATE_KEYS}" = "1" ]; then
		bbwarn "FIT_GENERATE_KEYS is set to 1 even though UBOOT_SIGN_ENABLE is set to 0. The keys will not be generated as they won't be used."
	fi

	if [ "${UBOOT_SIGN_ENABLE}" = "1" ] && [ "${FIT_GENERATE_KEYS}" = "1" ]; then

		# Generate keys to sign configuration nodes, only if they don't already exist
		if [ ! -f "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_KEYNAME}".key ] || \
			[ ! -f "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_KEYNAME}".crt ]; then

			# make directory if it does not already exist
			mkdir -p "${UBOOT_SIGN_KEYDIR}"

			bbnote "Generating RSA private key for signing fitImage"
			openssl genrsa ${FIT_KEY_GENRSA_ARGS} -out \
				"${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_KEYNAME}".key \
			"${FIT_SIGN_NUMBITS}"

			bbnote "Generating certificate for signing fitImage"
			openssl req ${FIT_KEY_REQ_ARGS} "${FIT_KEY_SIGN_PKCS}" \
				-key "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_KEYNAME}".key \
				-out "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_KEYNAME}".crt
		fi

		# Generate keys to sign image nodes, only if they don't already exist
		if [ ! -f "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_IMG_KEYNAME}".key ] || \
			[ ! -f "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_IMG_KEYNAME}".crt ]; then

			# make directory if it does not already exist
			mkdir -p "${UBOOT_SIGN_KEYDIR}"

			bbnote "Generating RSA private key for signing fitImage"
			openssl genrsa ${FIT_KEY_GENRSA_ARGS} -out \
				"${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_IMG_KEYNAME}".key \
			"${FIT_SIGN_NUMBITS}"

			bbnote "Generating certificate for signing fitImage"
			openssl req ${FIT_KEY_REQ_ARGS} "${FIT_KEY_SIGN_PKCS}" \
				-key "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_IMG_KEYNAME}".key \
				-out "${UBOOT_SIGN_KEYDIR}/${UBOOT_SIGN_IMG_KEYNAME}".crt
		fi
	fi
}

addtask kernel_generate_rsa_keys before do_assemble_fitimage after do_compile

kernel_do_deploy[vardepsexclude] = "DATETIME"
kernel_do_deploy:append() {
	# Update deploy directory
	if echo ${KERNEL_IMAGETYPES} | grep -wq "fitImage"; then

		if [ "${INITRAMFS_IMAGE_BUNDLE}" != "1" ]; then
			bbnote "Copying fit-image.its source file..."
			install -m 0644 ${B}/fit-image.its "$deployDir/fitImage-its-${KERNEL_FIT_NAME}.its"
			if [ -n "${KERNEL_FIT_LINK_NAME}" ] ; then
				ln -snf fitImage-its-${KERNEL_FIT_NAME}.its "$deployDir/fitImage-its-${KERNEL_FIT_LINK_NAME}"
			fi

			bbnote "Copying linux.bin file..."
			install -m 0644 ${B}/linux.bin $deployDir/fitImage-linux.bin-${KERNEL_FIT_NAME}${KERNEL_FIT_BIN_EXT}
			if [ -n "${KERNEL_FIT_LINK_NAME}" ] ; then
				ln -snf fitImage-linux.bin-${KERNEL_FIT_NAME}${KERNEL_FIT_BIN_EXT} "$deployDir/fitImage-linux.bin-${KERNEL_FIT_LINK_NAME}"
			fi
		fi

		if [ -n "${INITRAMFS_IMAGE}" ]; then
			bbnote "Copying fit-image-${INITRAMFS_IMAGE}.its source file..."
			install -m 0644 ${B}/fit-image-${INITRAMFS_IMAGE}.its "$deployDir/fitImage-its-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_NAME}.its"
			if [ -n "${KERNEL_FIT_LINK_NAME}" ] ; then
				ln -snf fitImage-its-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_NAME}.its "$deployDir/fitImage-its-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_LINK_NAME}"
			fi

			if [ "${INITRAMFS_IMAGE_BUNDLE}" != "1" ]; then
				bbnote "Copying fitImage-${INITRAMFS_IMAGE} file..."
				install -m 0644 ${B}/${KERNEL_OUTPUT_DIR}/fitImage-${INITRAMFS_IMAGE} "$deployDir/fitImage-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_NAME}${KERNEL_FIT_BIN_EXT}"
				if [ -n "${KERNEL_FIT_LINK_NAME}" ] ; then
					ln -snf fitImage-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_NAME}${KERNEL_FIT_BIN_EXT} "$deployDir/fitImage-${INITRAMFS_IMAGE_NAME}-${KERNEL_FIT_LINK_NAME}"
				fi
			fi
		fi
	fi
}