9adc9ea326
FastRPC is a communication protocol used to communicate with some remote processors on Qualcomm SoC's. It might be needed to configure sensors and to prevent an ADSP crash on the Pixel 3a. The programs provided by Google and Linaro don't work out of the box to set up an ADSP listener (even with kernel patches), and is a bit too unpleasant to read for my tastes. Add a new FastRPC implementation that will hopefully be more readable for everyone.
2.1 KiB
This is a proof-of-concept for interacting with the Snapdragon Sensor Core using the reverse-engineered protocol buffers. It was made to try to initialize it, but the Pixel 3a is missing some sensors once the firmware is loaded.
A best effort is made to prefix all log messages with sensh: so it's clear
which lines were entered by the user.
Requirements
- gcc
- libqrtr
- make
- protobuf-c
- qmic (https://github.com/andersson/qmic)
Installation
There is a Makefile to compile this:
$ make
Usage
Sensh doesn't automatically track, probe, or look up sensors; that is for a full implementation. Instead, it expects you to look up the sensor and copy the ID with your terminal emulator:
lookup accel_cal
sensh: accel_cal sensor found: A1392FDF217B7D9EI6648AED8C04DDFB9
attr A1392FDF217B7D9EI6648AED8C04DDFB9
sensh: name: ASH_CAL
sensh: vendor: GOOGLE
sensh: type: accel_cal
sensh: version: 1
sensh: api: sns_cal.proto
sensh: rates: 10.000000
sensh: stream type: 1
sensh: physical sensor: 0
sensh: available: 1
You can send 3 messages: lookup, attr, and watch. The lookup command returns SUIDs for the passed data type. The attr command returns attributes for the sensor. Finally, the watch command tells the sensor core to send events from a sensor whenever the sensor's value changes. The watch command is only valid if the stream type is 1 or 2.
An EOF (normally Ctrl+D) is enough to exit the shell unless the sensor core died.
References
The following sources were used as reference: