An aport, the units, and everything a phone needs to come up with a working
sensor without a single command being run by hand. Verified on the dev phone
across two reboots: modules-load.d loads qcomtee, tmpfiles builds the SFS
root, the mount unit brings up persist, and the daemon is ready 51 seconds
into the boot, owning net.reactivated.Fprint with the enrolled finger
visible.
The packaging shape is the one imsd uses for 81voltd. A versioned
provides="fprintd=..." satisfies plasma-workspace -- its Users KCM is the
enrolment UI and speaks exactly this bus name -- and excludes the real
fprintd, which is not tidiness: fprintd is D-Bus-activatable, so a client
call would otherwise start it and fight us for the name. The cost is the
fprintd-* CLIs, which go with the package.
fprintd-pam is an install_if subpackage pinned to the exact fprintd version,
so the provides breaks its condition and apk purges it -- taking pam_fprintd,
which is the entire point of the daemon, with it. Depending on it explicitly
is what keeps it, and it has no dependency on fprintd itself.
Two things the packaging exposed in the daemon:
The transcript is for experiments, not for a shipped daemon. A file per start
in an unrotated directory, recording the time of every unlock, to say what
the journal already has. It is now opt-in behind --log-dir, which is what
deploy-dev.sh passes since fplearn.sh reads it.
Taking it off the daemon path also took away the setvbuf it was doing as a
side effect of dup2'ing fd 1, and under systemd stdout is a pipe, which means
full buffering: the daemon started, worked, answered D-Bus calls, and printed
nothing. A working daemon that looks hung. stdout is now line-buffered from
the first line of main.
The config ships as generated by fp6fpcfg.py --daemon --verbose, sha256
b205c756914a66f1, because that is the file every accuracy number was measured
on. The quieter variant is untested and switching is a measurement.
The trustlet is not here and never will be: focal64.mbn is a proprietary
OEM-signed blob, and the unit's ConditionPathExists is what keeps the package
inert without it -- as it does on a kernel with no CONFIG_QCOMTEE.
CONFIG=<path> copied the file to /tmp under its own basename, while the remote
half installed /tmp/fingerprintd.json. A config named anything else therefore
left the PREVIOUS deploy's fingerprintd.json in place and installed that, while
printing ">> config installed" either way.
It went unnoticed until the printed config hash did not move after a deliberate
change, which is the only reason the hashes are printed at all. An experiment had
already been deployed against the wrong config by then.
The file now crosses under a fixed name, and a deploy with no CONFIG removes any
stale one on the phone rather than leaving something for a later run to pick up
by accident.
A refused enrolment sample is one of two things: an image the algorithm saw and
turned down (rc=0, samples remaining unchanged) or an error the trustlet never
got past (a negative rc). The touch line printed the count and the fid but not
the rc, so a run of twenty-two refusals in a row said nothing about which it was.
It does now.
EXTRA=... on deploy-dev.sh appends daemon flags, so a diagnostic session can
come up with --ta-log without editing the script or the unit by hand.
Nothing is packaged yet, so the binary, the scripts, the module load, the
persist mount and the transient unit all live in places a reboot wipes. That is
deliberate -- a reboot leaves a stock phone rather than a half-installed daemon
-- but its cost was a list of manual steps in a journal handoff, and the second
reboot of the day showed what that costs. The list is now a script.
Two things it gets right that a first draft did not. The readiness check is
scoped to the current systemd invocation: the journal persists across restarts
and reboots, so grepping the whole unit history matches the previous run's ready
line and reports the daemon up while the session is still coming up on the
worker thread. And the binary is copied under a new name and swapped in with mv
after the unit stops, because a running executable cannot be overwritten and
scp reports that only as "dest open: Failure" -- which a retry loop turns into
six identical failures instead of one clear one.
Verified from a freshly rebooted phone and again over a running daemon.
