Glossary

The following is a non-exhaustive glossary of weird terms used around cros development.

• GSC - the Google "Security" Chip, marked as H1B2/H1D2 on the board. Handles the SuzyQ bridge and a bunch of other misc stuff. Firmware is signed and not easily modifiable.
• Cr50, Ti50 - firmware portion of the GSC. Cr50 runs on the B2, Ti50 runs on the D2.
• SuzyQ - a Closed-Case Debug (CCD) solution. Generally, it's a special USB-C cable which gives you superpowers, exposing three debug serial ports (EC, AP, Cr50). It replaced the older Servo debug bridges, at least for most usecases.
• Servo - Can either refer to google's proprieteary 50pin debug connector, or a debug board of their design. Documentation is scarce, and in most cases it's easier to just use a SuzyQable.
• AP - Application Processor, google's name for your actual computer. This is what you run your system / applications on.
• EC, cros_ec - a microcontroller, the metaphorical glue holding everything together - it connects most of the HID (keyboard, TrackPoint, touchpad...), handles power (including charging the battery), controls the fans, etc. In terms of hardware, it's a Generic ARM, manufactured by one of Nuvoton, ITE, MEC or STM32 (list possibly non-exhaustive)
• FPMCU - apparently stands for FingerPrint MCU; On my board it's an STM32. I didn't do much research on that, as it seemingly doesn't touch anything I care about.
• board and baseboard - A baseboard can be thought of as a reference design that's later modified, creating specific boards (usually one per model). For instance, there are many boards basing on Zork baseboard, but they're all similar in specs.