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.
Rationale:
End users might not know exactly what hardware they have, they just want to find RubyFPV firmware options, so in the release page, in the list of released firmware packages, it makes sense to have all RubyFPV related configs in a single place in the list (so all start with the same RubyFPV prefix).
