Overview
webstlink is a debugger front-end for the ST-Link/v2 debug probe written in Javascript.
Where the ST-Link handles low-level operations like reading and writing to core CPU registers and accessing RAM, debugger front-ends like webstlink handle high-level operations like halting/resuming the CPU or reprogramming the on-chip flash memory.
Features
webstlink can be used to implement common debugger features such as:
- Reading/writing CPU registers
- Reading/writing RAM
- Writing/erasing flash memory
- Halting/single-stepping/resetting the CPU
- Displaying semihosted log messages
webstlink has been tested with standalone ST-Link/v2 dongles and ST-Link/v2-1 debuggers embedded in ST Nucleo development boards.
Demo
I’ve put together a live demo page online that can be used to test basic debugger functionality.
Future Work
webstlink is still very much a work-in-progress. Some features I would like to add include:
- ELF support, so that the debugger can display the current line of code that the CPU is halted on.
- Breakpoint support
- Disassembly support
- SWO trace support
Acknowledgements
webstlink is not entirely my original creation - most of the core code to handle the proprietary ST-Link USB protocol and the STM32 flash algorithms is ported from the pystlink project. My contribution has been to port it to Javascript and adjust it to work with the asynchronous WebUSB API instead of the synchronous libusb API.