systemd-veritysetup-generator — Unit generator for verity protected block devices
/usr/lib/systemd/system-generators/systemd-veritysetup-generator
systemd-veritysetup-generator is a generator that translates kernel command line options configuring verity protected block devices into native systemd units early at boot and when configuration of the system manager is reloaded. This will create systemd-veritysetup@.service(8) units as necessary.
Currently, only two verity devices may be set up with this generator, backing the root and /usr file systems of the
OS.
systemd-veritysetup-generator implements systemd.generator(7).
systemd-veritysetup-generator understands the following kernel command line parameters:
systemd.verity=, rd.systemd.verity=¶Takes a boolean argument. Defaults to "yes". If
"no", disables the generator entirely. rd.systemd.verity= is
honored only in the initrd while systemd.verity= is honored by both the main
system and in the initrd.
veritytab=, rd.veritytab=¶Takes a boolean argument. Defaults to "yes". If
"no", causes the generator to ignore any devices configured in
/etc/veritytab. rd.veritytab= is honored only in the initrd
while veritytab= is honored by both the main system and in the initrd.
roothash=¶Takes a root hash value for the root file system. Expects a hash value formatted in hexadecimal
characters of the appropriate length (i.e. most likely 256 bit/64 characters, or longer). If not specified via
systemd.verity_root_data= and systemd.verity_root_hash=, the hash and
data devices to use are automatically derived from the specified hash value. Specifically, the data partition
device is looked for under a GPT partition UUID derived from the first 128-bit of the root hash, the hash
partition device is looked for under a GPT partition UUID derived from the last 128-bit of the root hash. Hence
it is usually sufficient to specify the root hash to boot from a verity protected root file system, as
device paths are automatically determined from it — as long as the partition table is properly set up.
systemd.verity_root_data=, systemd.verity_root_hash=¶These two settings take block device paths as arguments and may be used to explicitly
configure the data partition and hash partition to use for setting up the verity protection for the root file
system. If not specified, these paths are automatically derived from the roothash= argument
(see above).
systemd.verity_root_options=¶Takes a comma-separated list of dm-verity options. Expects the following options
superblock=,
BOOLEANformat=,
NUMBERdata-block-size=,
BYTEShash-block-size=,
BYTESdata-blocks=,
BLOCKShash-offset=,
BYTESsalt=, HEXuuid=,
UUIDignore-corruption, restart-on-corruption, ignore-zero-blocks,
check-at-most-once, panic-on-corruption,
hash=, HASHfec-device=,
PATHfec-offset=, BYTESfec-roots= and
NUMroot-hash-signature=. See
veritysetup(8) for more
details.PATH|base64:HEX
usrhash=, systemd.verity_usr_data=, systemd.verity_usr_hash=, systemd.verity_usr_options=¶Equivalent to their counterparts for the root file system as described above, but
apply to the /usr/ file system instead.