15:58:12.641 B7C c4: uartlog PID 12268 -> logs/uart/b7c4-20261002-185812.log; waiting for fastboot <EMMC_SERIAL> (power off >= 90 s, then RESET held + battery -> USB)
15:58:12.646 board already in fastboot - waiting for it to disappear (power-off) first
15:59:03.129 fastboot device gone (power removed)
16:02:21.582 fastboot device present
Sending 'boot.img' (20792 KB)                      OKAY [  0.656s]
Booting                                            OKAY [  0.498s]
Finished. Total time: 1.178s
rc=0
16:05:21.921 ABORT: NCM not up after ~180 s - nothing touched, collect UART only
