OpenIPC/firmware dropped BR2_PACKAGE_JSONFILTER from every one of its
defconfigs in #2304, once the WebUI stopped calling it. builder's defconfigs are
its own files, so 97 of them kept selecting it. jsonfilter selects JSON_C and
LIBUBOX, and on a device that enables neither uqmi-openipc nor wifibroadcast-ng
nothing else selects libubox, so it and jsonfilter shipped for nothing.
That is what has had three devices over their rootfs cap:
hi3518ev200_lite_switcam-hs303 rootfs 5124KB/5120KB -4KB
ssc333_lite_babysense-see-hd-ip206 rootfs 5124KB/5120KB -4KB
ssc333_lite_meari-speed-6s rootfs 5128KB/5120KB -8KB
all three red on the nightly, meari since 2026-08-24. Bisecting meari across
firmware revisions lands on #2301, which added 408 bytes to the comment-stripped
sysupgrade script -- these images had no headroom left at all, and 408 bytes of
a genuine bug fix was enough to push one over a 4KB padding step. The fix is to
give them headroom, not to give back the bug fix.
Measured on ssc333_lite_meari-speed-6s, built the way builder.sh builds it --
devices/<item>/ copied over a firmware checkout at master, clean tree both times:
before rootfs.squashfs 5128KB/5120KB size exceeded by: 8KB
after rootfs.squashfs 5096KB/5120KB 24KB spare
-32KB, from /usr/bin/jsonfilter (18068 raw) and /usr/lib/libubox.so (30404 raw).
json-c does NOT go: majestic lists it in MAJESTIC_DEPENDENCIES, so buildroot
builds and installs it whether or not BR2_PACKAGE_JSON_C is set. Only the two
files above leave the image.
Two consumers genuinely need jsonfilter and both keep it:
* devices/apfpv's own etc/init.d/S99msposd reads majestic's config.json
through it, and ssc338q_apfpv and ssc378qe_apfpv do not enable
wifibroadcast-ng. Those two keep the symbol, with the reason written above
the line -- the same undeclared-runtime-dependency trap firmware #2305 had
to fix, and the reason this is 95 defconfigs and not 97.
* every other FPV device enables wifibroadcast-ng, whose Config.in selects
BR2_PACKAGE_JSONFILTER (added by #2305) for the same script. They keep it
without saying so.
LTE devices keep libubox through uqmi-openipc, which selects it independently.
Nothing else in this repository calls jsonfilter: grepping devices/ and
package/ finds only that one S99msposd line, and firmware's own tree has no
caller left outside wifibroadcast-ng.
piotr
