Linux

Here are the installation commands for a few Linux distributions.

Ubuntu 20.04 or newer / Debian 10 or newer

NOTE gdb-multiarch is the GDB command you'll use to debug your ARM Cortex-M programs.

$ sudo apt install gdb-multiarch minicom libunwind-dev

Fedora 32 or newer

NOTE gdb is the GDB command you'll use to debug your ARM Cortex-M programs.

$ sudo dnf install gdb minicom libunwind-devel

Arch Linux

NOTE arm-none-eabi-gdb is the GDB command you'll use to debug your ARM Cortex-M programs.

$ sudo pacman -S arm-none-eabi-gdb minicom libunwind-dev

Other distros

NOTE arm-none-eabi-gdb is the GDB command you'll use to debug your ARM Cortex-M programs.

For distros that don't have packages for ARM's pre-built toolchain, download the "Linux 64-bit" file and put its bin directory on your path. Here's one way to do it:

$ mkdir -p ~/local
$ cd ~/local
$ tar xjf /path/to/downloaded/XXX.tar.bz2

Then, use your editor of choice to append to your PATH in the appropriate shell init file (e.g. ~/.zshrc or ~/.bashrc):

PATH=$PATH:$HOME/local/XXX/bin

udev rules

These rules let you use USB devices like the micro:bit without root privilege, i.e. sudo.

Create this file in /etc/udev/rules.d with the content shown below.

$ cat /etc/udev/rules.d/69-microbit.rules

# CMSIS-DAP for microbit
ACTION!="add|change", GOTO="microbit_rules_end"
SUBSYSTEM=="usb", ATTR{idVendor}=="0d28", ATTR{idProduct}=="0204", TAG+="uaccess"
LABEL="microbit_rules_end"

Then reload the udev rules with:

$ sudo udevadm control --reload

If you had any board plugged to your computer, unplug them and then plug them in again, or run the following command.

$ sudo udevadm trigger

Verify permissions

Connect the micro:bit to your computer using a USB cable.

The micro:bit should now appear as a USB device (file) in /dev/bus/usb. Let's find out how it got enumerated:

$ lsusb | grep -i "NXP ARM mbed"
Bus 001 Device 065: ID 0d28:0204 NXP ARM mbed
$ # ^^^        ^^^

In my case, the micro:bit got connected to the bus #1 and got enumerated as the device #65. This means the file /dev/bus/usb/001/065 is the micro:bit. Let's check the file permissions:

$ ls -l /dev/bus/usb/001/065
crw-rw-r--+ 1 nobody nobody 189, 64 Sep  5 14:27 /dev/bus/usb/001/065

The permissions should be crw-rw-r--+, note the + at the end, then see your access rights by running the following command.

$ getfacl /dev/bus/usb/001/065
getfacl: Removing leadin '/' from absolute path names
# file: dev/bus/usb/001/065
# owner: nobody
# group: nobody
user::rw-
user:<YOUR-USER-NAME>:rw-
group::rw-
mask::rw-
other::r-

You should see your username in the list above with the rw- permissions, if not ... then check your udev rules and try re-loading them with:

$ sudo udevadm control --reload
$ sudo udevadm trigger

Now, go to the next section.