Pure Go library for the Serial Wire Debug (SWD) protocol

Serial Wire Debug (SWD) is a 2-pin (SWDIO/SWCLK) electrical alternative JTAG interface that has the JTAG protocol on top. It was developed by ARM® and is widely used for programming/debugging microcontrollers, PMICs, and other embedded devices. More information on SWD can be found in the ARM Debug Interface v5 Architecture Specification.

This library aims to implement the SWD protocol in pure Go. It was started to program the flash of STM32 MCUs.

Structure

The library is split into distinct parts that can be used independently.

Low-level IO

The io package provides the low-level SWD interface that can be implemented by different transport implementations. The library provides bitbang implementations for generic Linux sysfs GPIOs as well as Raspberry Pi GPIOs.

Hardware accelerated transports may implement the io.Accessor interface directly.

SWD protocol

The swd package contains the SWD protocol implementation for accessing debug and access port registers such as CSW, TAR or DRW.

Core Debug

The Core Debug layer is a higher-level interface that allows to access the debug registers or memory of a Cortex-M MCU. It is implemented in the core-debug package.

For more information on the Core Debug interface, refer to the Cortex-M3 Technical Reference Manual r1p1.

STM32

This layer provides convenience functions for interacting with STM32 MCUs such as reading, writing and erasing flash memory. It is implemented in the stm32 package.

Examples

Please refer to the examples directory for simple examples that read the IDCODE of a STM32 MCU or program the flash memory.

Contributing

Contributions are welcome as this project was started with a small scope but aims for more functionality and device support. Please open pull requests to extend it.

License

This library is licensed under the MIT license. See the LICENSE file for more information.