NEXUS7 second generation upgrade Android L

Toss for a while, and finally found very simple ...

1. Install Windows GDB and bootloader Drive, note open USB debug, and enter Bootloader is on the power button and the volume reduction key, as to unlock this presumably I also said more

2. Download the android L image (NEXUS5 and NEXUS7 are different, be careful to distinguish the download, otherwise there will be Flash bootloader signature inconsistent)

3. When running Flash-all, pay attention to enter the relevant directory, otherwise there will be no error such as printing,

4. By the way, FastBoot and GdB's gadgets are really good, and you can simply brush the machine by knocking on the line.