Keira DynApp Demo

This is an example dynamically-loaded application (.so) for KeiraOS.

It demonstrates:

• Drawing shapes (circles, lines, rectangles, triangles)
• Animating objects (bouncing ball with trail, spinning hexagon)
• Reading controller input (D-pad, A/B buttons)
• Playing buzzer sounds
• Using the frame buffer (double-buffered rendering via keira_queue_draw)

Building

Prerequisites

You need the Xtensa ESP32-S3 GCC toolchain. If you have PlatformIO installed, it's already available at:

~/.platformio/packages/toolchain-xtensa-esp32s3/bin/

Shows section layout, symbol table, and total size.

Compilation

cmake . && make

This produces build/demo.so.

If your toolchain is in a custom location, set the XTENSA_TOOLCHAIN_PATH environment variable:

XTENSA_TOOLCHAIN_PATH=/path/to/xtensa-toolchain/bin \
    cmake -DCMAKE_TOOLCHAIN_FILE=../xtensa-esp32s3.cmake ..
make

The toolchain file (xtensa-esp32s3.cmake) searches in this order:

1. XTENSA_TOOLCHAIN_PATH environment variable
2. PlatformIO default path (~/.platformio/packages/toolchain-xtensa-esp32s3/bin/)
3. System PATH

Running

1. Copy demo.so to the SD card on your Lilka device
2. Open the File Manager in KeiraOS
3. Navigate to and select demo.so
4. The app will start automatically

Controls

Button	Action
D-Pad	Move the ball
A	Speed boost
B	Exit the app

Writing Your Own DynApp

1. Create a new .c file with #include "keira_api.h"
2. Implement int app_main(int argc, char *argv[]) as the entry point
3. Use keira_* functions for display, controller, timing, and buzzer
4. Build with the same flags (see Makefile or CMakeLists.txt)
5. Copy the .so to the SD card and open it from the file manager

Important Notes

• No standard library is available (printf, malloc, etc. are provided by Keira's symbol table)
• The app runs in the same address space as Keira — crashes will reset the device
• argv[0] contains the path to the .so file on the SD card
• Call keira_queue_draw() after finishing each frame to display it
• Return from app_main or press B to exit gracefully

Available API

See keira_api.h for the complete API reference with documentation.