Adding SPI programming on a Raspberry Pi (from the IDE)

I've been working on a [stand-alone AVR programming solution](https://learn.sparkfun.com/tutorials/raspberry-pi-stand-alone-programmer) for SparkFun over the past couple years. Currently, we use Python (watching a GPIO) to engage a bash file that calls avrdude. We have found that the SPI hardware built into the raspberry pi is very reliable and it would be awesome to be able to also develop within the arduino IDE (on a raspi), and upload via SPI.

Would this be possible? Is it a crazy request?

No source file, test, or entry point is identified in the issue. Begin by tracing the Arduino IDE upload path on a Raspberry Pi and comparing it with the described Python/GPIO-to-bash avrdude workflow; done means a defined SPI upload flow is implemented and verified from the IDE.

Written by the indexing model from the issue text.