This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

Flash & Debug Host Tools

This guide describes the software tools you can run on your host workstation to flash and debug Zephyr applications.

Zephyr’s west tool has built-in support for all of these in its flash, debug, debugserver, and attach commands, provided your board hardware supports them and your Zephyr board directory’s board.cmake file declares that support properly. See Building, Flashing and Debugging for more information on these commands.

SAM Boot Assistant (SAM-BA)

Atmel SAM Boot Assistant (Atmel SAM-BA) allows In-System Programming (ISP) from USB or UART host without any external programming interface. Zephyr allows users to develop and program boards with SAM-BA support using west. Zephyr supports devices with/without ROM bootloader and both extensions from Arduino and Adafruit. Full support was introduced in Zephyr SDK 0.12.0.

The typical command to flash the board is:

west flash [ -r bossac ] [ -p /dev/ttyX ]

Flash configuration for devices:

These devices don’t need any special configuration. After building your application, just run west flash to flash the board.

Note

The CONFIG_BOOTLOADER_BOSSA_LEGACY Kconfig option should be used as last resource. Try configure first with Devices without ROM bootloader.

Typical flash layout and configuration

For bootloaders that reside on flash, the devicetree partition layout is mandatory. For devices that have a ROM bootloader, they are mandatory when the application uses a storage or other non-application partition. In this special case, the boot partition should be omitted and code_partition should start from offset 0. It is necessary to define the partitions with sizes that avoid overlaps, always.

A typical flash layout for devices without a ROM bootloader is:

/ {
        chosen {
                zephyr,code-partition = &code_partition;
        };
};

&flash0 {
        partitions {
                compatible = "fixed-partitions";
                #address-cells = <1>;
                #size-cells = <1>;

                boot_partition: partition@0 {
                        label = "sam-ba";
                        reg = <0x00000000 0x2000>;
                        read-only;
                };

                code_partition: partition@2000 {
                        label = "code";
                        reg = <0x2000 0x3a000>;
                        read-only;
                };

                /*
                * The final 16 KiB is reserved for the application.
                * Storage partition will be used by FCB/LittleFS/NVS
                * if enabled.
                */
                storage_partition: partition@3c000 {
                        label = "storage";
                        reg = <0x0003c000 0x00004000>;
                };
        };
};

A typical flash layout for devices with a ROM bootloader and storage partition is:

/ {
        chosen {
                zephyr,code-partition = &code_partition;
        };
};

&flash0 {
        partitions {
                compatible = "fixed-partitions";
                #address-cells = <1>;
                #size-cells = <1>;

                code_partition: partition@0 {
                        label = "code";
                        reg = <0x0 0xF0000>;
                        read-only;
                };

                /*
                * The final 64 KiB is reserved for the application.
                * Storage partition will be used by FCB/LittleFS/NVS
                * if enabled.
                */
                storage_partition: partition@F0000 {
                        label = "storage";
                        reg = <0x000F0000 0x00100000>;
                };
        };
};

Enabling SAM-BA runner

In order to instruct Zephyr west tool to use the SAM-BA bootloader the board.cmake file must have include(${ZEPHYR_BASE}/boards/common/bossac.board.cmake) entry. Note that Zephyr tool accept more entries to define multiple runners. By default, the first one will be selected when using west flash command. The remaining options are available passing the runner option, for instance west flash -r bossac.

More implementation details can be found in the Supported Boards documentation. As a quick reference, see these three board documentation pages:

OpenOCD Debug Host Tools

OpenOCD is a community open source project that provides GDB remote debugging and flash programming support for a wide range of SoCs. A fork that adds Zephyr RTOS-awareness is included in the Zephyr SDK; otherwise see Getting OpenOCD for options to download OpenOCD from official repositories.

These debug host tools are compatible with the following debug probes:

Check if your SoC is listed in OpenOCD Supported Devices.

Note

On Linux, openocd is available though the Zephyr SDK. Windows users should use the following steps to install openocd:

  • Download openocd for Windows from here: OpenOCD Windows

  • Copy bin and share dirs to C:\Program Files\OpenOCD\

  • Add C:\Program Files\OpenOCD\bin to ‘PATH’ environment variable

pyOCD Debug Host Tools

pyOCD is an open source project from Arm that provides GDB remote debugging and flash programming support for Arm Cortex-M SoCs. It is distributed on PyPi and installed when you complete the Get Zephyr and install Python dependencies step in the Getting Started Guide. pyOCD includes support for Zephyr RTOS-awareness.

These debug host tools are compatible with the following debug probes:

Check if your SoC is listed in pyOCD Supported Devices.

Lauterbach TRACE32 Debug Host Tools

Lauterbach TRACE32 is a product line of microprocessor development tools, debuggers and real-time tracer with support for JTAG, SWD, NEXUS or ETM over multiple core architectures, including Arm Cortex-A/-R/-M, RISC-V, Xtensa, etc. Zephyr allows users to develop and program boards with Lauterbach TRACE32 support using west.

The runner consists of a wrapper around TRACE32 software, and allows a Zephyr board to execute a custom start-up script (Practice Script) for the different commands supported, including the ability to pass extra arguments from CMake. Is up to the board using this runner to define the actions performed on each command.

Install Lauterbach TRACE32 Software

Download Lauterbach TRACE32 software from the Lauterbach TRACE32 download website (registration required) and follow the installation steps described in Lauterbach TRACE32 Installation Guide.

Flashing and Debugging

Set the environment variable T32_DIR to the TRACE32 system directory. Then execute west flash or west debug commands to flash or debug the Zephyr application as detailed in Building, Flashing and Debugging. The debug command launches TRACE32 GUI to allow debug the Zephyr application, while the flash command hides the GUI and perform all operations in the background.

By default, the t32 runner will launch TRACE32 using the default configuration file named config.t32 located in the TRACE32 system directory. To use a different configuration file, supply the argument --config CONFIG to the runner, for example:

west flash --config myconfig.t32

For more options, run west flash --context -r t32 to print the usage.

Zephyr RTOS Awareness

To enable Zephyr RTOS awareness follow the steps described in Lauterbach TRACE32 Zephyr OS Awareness Manual.