docs: This README focuses on:

- Quick setup steps
- Essential project structure
- Key configuration points
- Basic debugging

Author: schkovich

README.md

@@ -0,0 +1,59 @@
+# Development Setup Guide
+
+This project uses arduino-pico core for debugging RP2040-based Arduino Pico programs with local modifications.
+
+## Prerequisites
+
+- [Arduino Pico](https://github.com/earlephilhower/arduino-pico) core
+- [PlatformIO](https://platformio.org/)
+- CMSIS-DAP compatible debug probe
+
+## Setup Process
+
+1. Clone those repositories:
+```bash
+git clone https://github.com/schkovich/arduino-pico.git 
+cd arduino-pico
+git checkout execute-sync@7c51742
+git submodule update --init
+cd ..
+git clone [email protected]:schkovich/pico-sdk-tests.git
+cd pico-sdk-tests
+```
+
+## Project Structure
+```plaintext
+
+├── arduino-pico # Forked arduino-pico core
+├── pico-sdk-tests
+│   ├── lib
+│   ├── .pio # PlatformIO build directory
+│   ├── scripts # Debug scripts
+│   └── src
+```
+
+## Project configuration
+The arduino-pico core is configured in [platformio.ini](https://docs.platformio.org/en/latest/projectconf/index.html#platformio-ini-project-configuration-file) via [platform_package](https://docs.platformio.org/en/latest/projectconf/sections/env/options/platform/platform_packages.html#platform-packages) option, pointing to the [local folder](https://docs.platformio.org/en/latest/core/userguide/pkg/cmd_install.html#local-folder) and “Symbolic Link” feature:
+```ini
+[env:debug]
+board = nanorp2040connect
+framework = arduino
+platform = https://github.com/maxgerhardt/platform-raspberrypi.git
+board_build.core = earlephilhower
+platform_packages =
+    framework-arduinopico@symlink://../arduino-pico
+```
+## Building Core Components
+The pico-sdk build process:
+
+1. Compiles core SDK libraries
+2. Generates boot stage 2 code for different flash chips
+3. Produces required build artifacts for both RP2040 and RP2350
+
+For detailed build steps, see [make-libpico.sh](https://github.com/schkovich/arduino-pico/blob/execute-sync%407c51742/tools/libpico/make-libpico.sh) in the arduino-pico core.
+
+### Development Workflow
+
+- Pico SDK and async_context are pre-built statically linked to the project
+- The project is built using [PlatformIO](https://docs.platformio.org/en/latest/core/index.html)
+- Debug using CMSIS-DAP probe