The upgrade turns a board's ST-LINK interface into a fully functional J-Link, which can then be employed to debug the board's application processor. By upgrading to the J-Link firmware, developers will subsequently be able to set an unlimited number of breakpoints in Flash memory and debug their applications considerably faster.
The J-Link firmware offers compatibility with all major tool chains, including those using GDB (GNU Debugger), on all major host platforms (Windows, Mac, Linux), while also attaining elevated operational benchmarks, including the fastest download speed into RAM and Flash memory. The tool needed to upgrade the firmware of the on-board ST-LINKs can be downloaded free of charge from Segger's website. If it ever becomes necessary to do so, the exchange process is completely reversible, restoring the original ST-LINK functionality.
With J-Link firmware installed, users of STM32 Nucleo and STM32 Discovery evaluation boards can use tools such as Segger RTT and SystemView for real-time analysis purposes.
“The availability of J-Link firmware for ST-LINK provides a professional debug solution across the complete range of ST evaluation boards at all price points... it showcases the high flash programming speed of the ST boards and enables even more tool chains to use our STM32 Nucleo and STM32 Discovery boards.