I’ve installed the following bootloader, kernel, and rootfs:
- dragonboard410c_bootloader_emmc_linux-72.zip
- linaro-jessie-developer-qcom-snapdragon-arm64-20161006-144.img.gz
- boot-linaro-jessie-qcom-snapdragon-arm64-20161006-144.img.gz
I’ve also installed the following packages:
gpsd-clients gnss-gpsd
I’ve also started the DSP:
sudo systemctl start qdsp-start.service
After this, I am able to use xgps to monitor the GPS status.
However, I am looking for ways to control the GPS beyond the default configuration that is applied.
I’ve also briefly looked at the IPC driver here:
https://git.linaro.org/landing-teams/working/qualcomm/kernel.git/tree/net/qrtr
I am still looking for the userspace code that uses this driver
I’m guessing its the source for this package: gnss-gpsd ← I cannot seem to locate this
If I understand correctly userspace and GPS communication works like so:
[xgps] <—> [gnss-gpsd] <—> [qrtr] <-IPC-> [dsp code] <-SSBI-> [WGR7640]
Also, I’ve identified this manual:
The doc makes reference to ‘singlewire serial bus interface (SSBI) for efficient initialization, status, and control’. However, it doesn’t go into further detail on how this communication works (I’m assuming it’s proprietary and currently done using the DSP)
Is there any documentation, DSP code, kernel or userspace code, that may give better insight into how the GPS is currently configured and what additional configuration may be available?
Ultimately, I would like to turn off the WGR7640 chip completely or turn off as much of the internal circuitry as possible.
I appreciate all the hard work that has been done thus far from the 96 boards and the community as a whole. Also, thanks in advance for reviewing this.