The Micro:Bit is a very small ARM Cortex-M0 board designed by the BBC for computer education. It's fitted with a Nordic nRF51 Bluetooth enabled microcontroller and an embedded programmer. You can get it at:
How to setup the Ada development environment for the Micro:Bit
J-Link embedded programmer
In order to use gdb to program and debug the Micro:Bit, you have to replace the firmware of the embedded programmer. Go to this page: https://www.segger.com/bbc-micro-bit.html and follow the instructions toinstall the J-Link firmware on the Micro:Bit.
J-Link GDBServer
Now you need to download and install the "J-Link Software and Documentation Pack" for your development machine (Linux, Windows, MacOS) from this page: https://www.segger.com/downloads/jlink
You can now start the J-Link GDB server, for instance on Linux:
$ <JLINK_INSTALLATION_DIR>/JLinkGDBServer -device nrf51822
Note that JLinkGDBServer may require administrator/root access to talk to the board. To avoid running JLinkGDBServer as root on Linux, copy the UDev rule file "99-jlink.rules" from the J-Link installation to "/etc/udev" and reload the rules:
$ sudo cp <JLINK_INSTALLATION_DIR>/99-jlink.rules /etc/udev/rules.d
$ sudo udevadm control --reload-rules
Install the Ada ZFP run-time
Go to theMicro:Bit example directory and download or clone the run-time from Shawn Nock's GitHub repository: https://github.com/nocko/zfp-nrf51
$ cd da_Drivers_Library/examples/MicroBit/
$ git clone https://github.com/nocko/zfp-nrf51
Open the example project and build it
Start GNAT Programming studio (GPS) and open the Micro:Bit example project: "Ada_Drivers_Library/examples/MicroBit/microbit_example.gpr".
Press F4 and then press Enter to build the project.
program and debugthe board
In GPS, start a debug session with the top menu "Debug -> Initialize -> main". GPS will start gdb and connect it to the J-Link debugger.
In the gdb console, use the "load" command to program the board:
(gdb) load
Loading section .text, size 0xbd04 lma 0x0
Loading section .ARM.exidx, size 0x8 lma 0xbd04
[...]
Reset the board with this command
(gdb) monitor reset
And finally use the "continue" command to run the program:
(gdb) continue
You can interrupt the execution with the "CTRL+backslash" shortcut and then insert breakpoints, step through the application, inspect memory, etc.