Servo
From chromebook hackers wiki

Depending on the context, Servo may refer to one of the following:
- Servo v2/Micro/v4/v4.1, google's debug probes. Not available to the general public, neither are the schematics. Most info about them comes from this chromium.googlesource.com page.
- Yoshi Flex Cable, an adapter to connect the Servo v2 to a Servo Debug Port
- Servo Debug port - a proprietary port, exposing several UARTs, SPI, power/reset buttons and several others.