kernel: Integrate initramfs into Guest kernel

Integrate initramfs into guest kernel as one binary,
which will be measured by the firmware together.

Fixes: #6674

Signed-off-by: Wang, Arron <arron.wang@intel.com>

tools/packaging/kernel/build-kernel.sh

@@ -31,6 +31,7 @@ readonly default_kernel_config_dir="${script_dir}/configs"
 # Default path to search for kernel config fragments
 readonly default_config_frags_dir="${script_dir}/configs/fragments"
 readonly default_config_whitelist="${script_dir}/configs/fragments/whitelist.conf"
+readonly default_initramfs="${script_dir}/initramfs.cpio.gz"
 # GPU vendor
 readonly GV_INTEL="intel"
 readonly GV_NVIDIA="nvidia"
@@ -64,6 +65,8 @@ kernel_url=""
 #Linux headers for GPU guest fs module building
 linux_headers=""
 
+MEASURED_ROOTFS=${MEASURED_ROOTFS:-no}
+
 packaging_scripts_dir="${script_dir}/../scripts"
 source "${packaging_scripts_dir}/lib.sh"
 
@@ -269,11 +272,19 @@ get_kernel_frag_path() {
 		fi
 	fi
 
-	if [[ "${conf_guest}" != "" ]];then
+	if [ "${MEASURED_ROOTFS}" == "yes" ]; then
 		info "Enabling config for confidential guest trust storage protection"
 		local cryptsetup_configs="$(ls ${common_path}/confidential_containers/cryptsetup.conf)"
 		all_configs="${all_configs} ${cryptsetup_configs}"
 
+		if [ -f "${default_initramfs}" ]; then
+			info "Enabling config for confidential guest measured boot"
+			local initramfs_configs="$(ls ${common_path}/confidential_containers/initramfs.conf)"
+			all_configs="${all_configs} ${initramfs_configs}"
+		fi
+	fi
+
+	if [[ "${conf_guest}" != "" ]];then
 		info "Enabling config for '${conf_guest}' confidential guest protection"
 		local conf_configs="$(ls ${arch_path}/${conf_guest}/*.conf)"
 		all_configs="${all_configs} ${conf_configs}"
@@ -422,6 +433,11 @@ setup_kernel() {
 	[ -n "${hypervisor_target}" ] || hypervisor_target="kvm"
 	[ -n "${kernel_config_path}" ] || kernel_config_path=$(get_default_kernel_config "${kernel_version}" "${hypervisor_target}" "${arch_target}" "${kernel_path}")
 
+	if [ "${MEASURED_ROOTFS}" == "yes" ] && [ -f "${default_initramfs}" ]; then
+		info "Copying initramfs from: ${default_initramfs}"
+		cp "${default_initramfs}" ./
+	fi
+
 	info "Copying config file from: ${kernel_config_path}"
 	cp "${kernel_config_path}" ./.config
 	make oldconfig

tools/packaging/kernel/configs/fragments/common/confidential_containers/initramfs.conf

@@ -0,0 +1 @@
+CONFIG_INITRAMFS_SOURCE="initramfs.cpio.gz"

tools/packaging/static-build/kernel/build.sh

@@ -25,6 +25,7 @@ sudo docker pull ${container_image} || \
 
 sudo docker run --rm -i -v "${repo_root_dir}:${repo_root_dir}" \
 	-w "${PWD}" \
+	--env MEASURED_ROOTFS="${MEASURED_ROOTFS:-}" \
 	"${container_image}" \
 	bash -c "${kernel_builder} $* setup"