| #!/bin/bash |
| |
| # Copyright (c) 2010 The Chromium OS Authors. All rights reserved. |
| # Use of this source code is governed by a BSD-style license that can be |
| # found in the LICENSE file. |
| |
| # Helper script that generates the signed kernel image |
| |
| . "$(dirname "$0")/common.sh" |
| |
| get_default_board |
| |
| # Flags. |
| DEFINE_string arch "x86" \ |
| "The boot architecture: arm or x86. (Default: x86)" |
| DEFINE_string to "/tmp/vmlinuz.image" \ |
| "The path to the kernel image to be created. (Default: /tmp/vmlinuz.image)" |
| DEFINE_string hd_vblock "/tmp/vmlinuz_hd.vblock" \ |
| "The path to the installed kernel's vblock (Default: /tmp/vmlinuz_hd.vblock)" |
| DEFINE_string vmlinuz "vmlinuz" \ |
| "The path to the kernel (Default: vmlinuz)" |
| DEFINE_string working_dir "/tmp/vmlinuz.working" \ |
| "Working directory for in-progress files. (Default: /tmp/vmlinuz.working)" |
| DEFINE_boolean keep_work ${FLAGS_FALSE} \ |
| "Keep temporary files (*.keyblock, *.vbpubk). (Default: false)" |
| DEFINE_string keys_dir "${SRC_ROOT}/platform/vboot_reference/tests/testkeys" \ |
| "Directory with the RSA signing keys. (Defaults to test keys)" |
| # Note, to enable verified boot, the caller would manually pass: |
| # --boot_args='dm="... /dev/sd%D%P /dev/sd%D%P ..." \ |
| # --root=/dev/dm-0 |
| DEFINE_string boot_args "noinitrd" \ |
| "Additional boot arguments to pass to the commandline (Default: noinitrd)" |
| DEFINE_string root "/dev/sd%D%P" \ |
| "Expected device root (Default: root=/dev/sd%D%P)" |
| |
| # If provided, will automatically add verified boot arguments. |
| DEFINE_string rootfs_image "" \ |
| "Optional path to the rootfs device or image.(Default: \"\")" |
| DEFINE_string rootfs_hash "" \ |
| "Optional path to output the rootfs hash to. (Default: \"\")" |
| DEFINE_integer verity_error_behavior 2 \ |
| "Verified boot error behavior [0: I/O errors, 1: reboot, 2: nothing] \ |
| (Default: 2)" |
| DEFINE_integer verity_tree_depth 1 \ |
| "Optional Verified boot hash tree depth. (Default: 1)" |
| DEFINE_integer verity_max_ios 1024 \ |
| "Optional number of outstanding I/O operations. (Default: 1024)" |
| DEFINE_string verity_hash_alg "sha1" \ |
| "Cryptographic hash algorithm used for dm-verity. (Default: sha1)" |
| |
| # Parse flags |
| FLAGS "$@" || exit 1 |
| eval set -- "${FLAGS_ARGV}" |
| |
| # Die on error |
| set -e |
| |
| verity_args= |
| # Even with a rootfs_image, root= is not changed unless specified. |
| if [[ -n "${FLAGS_rootfs_image}" && -n "${FLAGS_rootfs_hash}" ]]; then |
| # Gets the number of blocks. 4096 byte blocks _are_ expected. |
| root_fs_blocks=$(sudo dumpe2fs "${FLAGS_rootfs_image}" 2> /dev/null | |
| grep "Block count" | |
| tr -d ' ' | |
| cut -f2 -d:) |
| root_fs_block_sz=$(sudo dumpe2fs "${FLAGS_rootfs_image}" 2> /dev/null | |
| grep "Block size" | |
| tr -d ' ' | |
| cut -f2 -d:) |
| info "rootfs is ${root_fs_blocks} blocks of ${root_fs_block_sz} bytes" |
| if [[ ${root_fs_block_sz} -ne 4096 ]]; then |
| error "Root file system blocks are not 4k!" |
| fi |
| |
| info "Generating root fs hash tree." |
| # Runs as sudo in case the image is a block device. |
| table=$(sudo verity create ${FLAGS_verity_tree_depth} \ |
| ${FLAGS_verity_hash_alg} \ |
| ${FLAGS_rootfs_image} \ |
| ${root_fs_blocks} \ |
| ${FLAGS_rootfs_hash}) |
| if [[ -f "${FLAGS_rootfs_hash}" ]]; then |
| sudo chmod a+r "${FLAGS_rootfs_hash}" |
| fi |
| # Don't claim the root device unless the root= flag is pointed to |
| # the verified boot device. Doing so will claim /dev/sdDP out from |
| # under the system. |
| if [[ ${FLAGS_root} = "/dev/dm-0" ]]; then |
| table=${table//HASH_DEV//dev/sd%D%P} |
| table=${table//ROOT_DEV//dev/sd%D%P} |
| fi |
| verity_args="dm=\"vroot none ro,${table}\"" |
| info "dm-verity configuration: ${verity_args}" |
| fi |
| |
| mkdir -p "${FLAGS_working_dir}" |
| cat <<EOF > "${FLAGS_working_dir}/boot.config" |
| root=${FLAGS_root} |
| dm_verity.error_behavior=${FLAGS_verity_error_behavior} |
| dm_verity.max_bios=${FLAGS_verity_max_ios} |
| ${verity_args} |
| ${FLAGS_boot_args} |
| EOF |
| |
| WORK="${WORK} ${FLAGS_working_dir}/boot.config" |
| info "Emitted cross-platform boot params to ${FLAGS_working_dir}/boot.config" |
| |
| # FIXME: At the moment, we're working on signed images for x86 only. ARM will |
| # support this before shipping, but at the moment they don't. |
| if [[ "${FLAGS_arch}" = "x86" ]]; then |
| |
| # Legacy BIOS will use the kernel in the rootfs (via syslinux), as will |
| # standard EFI BIOS (via grub, from the EFI System Partition). Chrome OS |
| # BIOS will use a separate signed kernel partition, which we'll create now. |
| # FIXME: remove serial output, debugging messages. |
| mkdir -p ${FLAGS_working_dir} |
| cat <<EOF | cat - "${FLAGS_working_dir}/boot.config" \ |
| > "${FLAGS_working_dir}/config.txt" |
| earlyprintk=serial,ttyS0,115200 |
| console=ttyS0,115200 |
| init=/sbin/init |
| add_efi_memmap |
| boot=local |
| rootwait |
| ro |
| noresume |
| noswap |
| i915.modeset=1 |
| loglevel=7 |
| cros_secure |
| kern_guid=%U |
| EOF |
| WORK="${WORK} ${FLAGS_working_dir}/config.txt" |
| |
| # We sign the image with the recovery_key, because this is what goes onto the |
| # USB key. We can only boot from the USB drive in recovery mode. |
| |
| # Create and sign the kernel blob |
| vbutil_kernel \ |
| --pack "${FLAGS_to}" \ |
| --keyblock "${FLAGS_keys_dir}/recovery_kernel.keyblock" \ |
| --signprivate "${FLAGS_keys_dir}/recovery_kernel_data_key.vbprivk" \ |
| --version 1 \ |
| --config "${FLAGS_working_dir}/config.txt" \ |
| --bootloader /lib64/bootstub/bootstub.efi \ |
| --vmlinuz "${FLAGS_vmlinuz}" |
| |
| # And verify it. |
| vbutil_kernel \ |
| --verify "${FLAGS_to}" \ |
| --signpubkey "${FLAGS_keys_dir}/recovery_key.vbpubk" |
| |
| |
| # Now we re-sign the same image using the normal keys. This is the kernel |
| # image that is put on the hard disk by the installer. Note: To save space on |
| # the USB image, we're only emitting the new verfication block, and the |
| # installer just replaces that part of the hard disk's kernel partition. |
| vbutil_kernel \ |
| --repack "${FLAGS_hd_vblock}" \ |
| --vblockonly \ |
| --keyblock "${FLAGS_keys_dir}/kernel.keyblock" \ |
| --signprivate "${FLAGS_keys_dir}/kernel_data_key.vbprivk" \ |
| --oldblob "${FLAGS_to}" |
| |
| |
| # To verify it, we have to replace the vblock from the original image. |
| tempfile=$(mktemp) |
| trap "rm -f $tempfile" EXIT |
| cat "${FLAGS_hd_vblock}" > $tempfile |
| dd if="${FLAGS_to}" bs=65536 skip=1 >> $tempfile |
| |
| vbutil_kernel \ |
| --verify $tempfile \ |
| --signpubkey "${FLAGS_keys_dir}/kernel_subkey.vbpubk" |
| |
| rm -f $tempfile |
| trap - EXIT |
| |
| elif [[ "${FLAGS_arch}" = "arm" ]]; then |
| # FIXME: For now, ARM just uses the unsigned kernel by itself. |
| cp -f "${FLAGS_vmlinuz}" "${FLAGS_to}" |
| else |
| error "Unknown arch: ${FLAGS_arch}" |
| fi |
| |
| set +e # cleanup failure is a-ok |
| |
| if [[ ${FLAGS_keep_work} -eq ${FLAGS_FALSE} ]]; then |
| info "Cleaning up temporary files: ${WORK}" |
| rm ${WORK} |
| rmdir ${FLAGS_working_dir} |
| fi |
| |
| info "Kernel partition image emitted: ${FLAGS_to}" |
| |
| if [[ -f ${FLAGS_rootfs_hash} ]]; then |
| info "Root filesystem hash emitted: ${FLAGS_rootfs_hash}" |
| fi |