$ fastboot flash boot boot.img
< waiting for device >
看看devices
$ fastboot devices
no permissions fastboot
唔……
$ sudo chown root:root /bin/fastboot
$ sudo chmod +s /bin/fastboot
$ fastboot devices
7D89BCD6 fastboot
$ fastboot flash boot boot.img
target reported max download size of 465031168 bytes
sending 'boot' (9409 KB)...
OKAY [ 0.665s]
writing 'boot'...
OKAY [ 0.961s]
finished. total time: 1.666s
好了