openwrt

The 360V6 has A/B dual-partition flash: two complete rootfs copies and a bootloader slot flag that selects one at boot. Updates write the inactive partition and leave the running one alone. If a write fails or is interrupted, the router can still boot the old system.

OpenWrt's sysupgrade ignored the layout and wrote the running partition in place. A power loss or bad image mid-write left the device unbootable, recoverable only over TTL. I added proper A/B support upstream, and it has merged.