the idea is for all zig code to use C LVGL only via this
new module lvgl.zig, all display and input driver/devices is handled
by drv.zig.
this makes C/zig nicely compartmentalized in just a handful places.
the nd/ngui protocol is a simple TLV: message tag, length and
a json-encoded payload. the issue is with the (tag, length) header which
was written/read by using raw memory pointers, such as
Writer.writeStruct. in addition, tag ordinal values were auto-generated
by the compiler.
all those deficiencies may potentially lead to bugs hard to find or
serious data leaks.
serializing and deserializing the (tag, length) header manually
makes it more robust and eliminates the footgun.
10min looks quite excessive but based on conversations in
https://github.com/bitcoin/bitcoin/commit/7fb7acfc, better safe than
sorry. same for lnd. in any case, 30sec was indeed far too short to
begin with, especially for bitcoind.
services are now stopped in parallel, though. so, the poweroff sequence
goes faster.
16px looks easier to read but IPv6 addresses don't fit in the wifi
settings panel anymore. need to find a better way how to display them or
change font.
alex