This document describes the process of adding support for a new ESP32 device (what retro-go calls a target).
You will need a working installation of esp-idf. Versions 4.3 to 5.2 are supported.
Before using your own patch of retro-go, make a clean build of retro go using bare configurations
./rg_tool.py build-img launcher --target esp32s3-devkit-c
Since we aren't using other setups, like ODROID-GO, we will be building .img files, not .fw. Use ./rg_tool.py build-img to build imgs.
Make sure a basic setup is working before continuing to patch the code for your setup
If it doesn't, refer to BUILDING.md. Also check your esp-idf installation and make sure you have it set up in your environment (run idf.py --version to check)
./rg_tool.py build-img launcher --target esp32s3-devkit-c
Retro-Go uses reusable hardware components, so it is easy to set it up for your own hardware.
You will find the targets (configs for each device) in components/retro-go/targets
To make a base one, copy esp32s3-devkit-c and rename it.
config.h has the bulk of your configurations.
First, change RG_TARGET_NAME to match the name of your target folder.
Most of it, you will need to figure out the correct parameters for (eg. Storage and Audio)
Display
If you aren't using the ILI9341 screen driver, you will need to change the SCREEN_DRIVER parameter. (Otherwise, just change the following settings and continue).
(You will find more display configuration in the SPI Display section below)
For now, only the ILI9341 is included. Increment the number. Then in components/retro-go/rg_display.c, find this part
#if RG_SCREEN_DRIVER == 0 /* ILI9341 */
#include "drivers/display/ili9341.h"
#elif RG_SCREEN_DRIVER == 99
#include "drivers/display/sdl2.h"
#else
#include "drivers/display/dummy.h"
#endif
Add a #elif for your SCREEN_DRIVER. In the body, use #include "drivers/display/(YOUR DISPLAY DRIVER).h" (eg. st7789.h).
You will need to create that file for your display. Unfortunately, there is no one-for-all way to make this. It will need the same template as the other display drivers there, but it will differ for each display. To start, check the Retro-Go issues on GitHub and try searching on Google.
Make this driver in components/retro-go/drivers/display
Input
Back in config.h, you will see the configuration for an I2C gamepad. If you aren't using that, you can make your own parameters based on the existing input forms in components/retro-go/rg_input.c
You can also write your own input driver for unique input forms. Just look at the existing code in rg_input.c and match that
sdkconfig is used by ESP-IDF to build the code for the ESP32 itself. It is hard to manually write it all out, so you can use menuconfig
For this, go back to your root folder. Build the launcher for your target (this will make sure you have the correct ESP32 board selected).
./rg_tool.py clean
./rg_tool.py build launcher --target (YOUR TARGET)
Then cd into launcher and run idf.py menuconfig. Navigate to Serial Flasher Config and adjust it all to your board. Make sure to save the changes and exit.
Use this generated sdkconfig in your target with
cd ..
mv -f launcher/sdkconfig components/retro-go/targets/retrotoids/sdkconfig
This will configure ESP-IDF to run on your board
Change the target board in env.py to match yours
After completing all these steps, you should be able to build your apps with rg_tool. See BUILDING.md for more info about this and flashing. Make sure to use the steps for .img, NOT .fw