hwinfo_get_reset_cause() reads a latched register. It was read inline in
main_companion.cpp and cleared there, so the repeater, room server and
observer never read it and never cleared it: their flags carried into the next
boot, and whichever role read first defined what any later reader would see.
helpers/boot_info.c reads it once in a SYS_INIT at POST_KERNEL, logs it,
stores it and clears the register. That runs before main() on every role.
zephcore_boot_reset_cause() hands out the stored copy and reports false where
the platform has no support, which a caller can distinguish from a cause of 0.
The clear's return is discarded deliberately: ESP32 has no
hwinfo_clear_reset_cause() implementation, so the weak stub returns -ENOSYS.
The capture is still correct there; only the next boot's reading is not.
Logging in boot_info_init() rather than only in the consuming role matters
because the clear now happens everywhere. Without it a repeater that rebooted
on WATCHDOG or LOCKUP would have the evidence cleared and recorded nowhere,
where before it survived in the register for whoever read it over SWD.
main_companion.cpp reads the stored copy and renders through a table with one
row per RESET_* bit, so a cause with no label is no longer logged as bare hex.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
