Skip to content

flashing.md

Latest commit

 

History

History
105 lines (75 loc) · 2.67 KB

flashing.md

File metadata and controls

105 lines (75 loc) · 2.67 KB
Raw

J-Link Flashing — west-env

west-env supports firmware flashing using host-side J-Link tools as the default strategy. Build artifacts are synced from the container to the host filesystem, then flashed with the native J-Link installation. No USB passthrough into the container is required.

Default flow (host mode)

[container] west build → zephyr.elf / zephyr.hex
       ↓  west env sync --back
[host]  artifacts/build/zephyr/zephyr.hex
       ↓  west env flash artifacts/build/zephyr/zephyr.hex
[host]  JLinkExe (Windows) / JLinkExe (Linux/macOS)
       ↓
[target board via USB J-Link]

No USB passthrough into the container. No Zephyr runner inside the container.

Configuration

jlink:
  mode: host        # (default) flash with host J-Link tools
  # mode: tcp-server  # start GDB server on host; GDB connects from container
  # mode: none        # disable flash/debug via west-env

Prerequisites

  1. Install SEGGER J-Link.
  2. Connect the target board via a J-Link probe.
  3. west env doctor reports [PASS] J-Link host tools: /path/to/JLinkExe.

Default search paths:

  • Windows: C:\Program Files\SEGGER\JLink\JLink.exe (also checks PATH)
  • Linux: /opt/SEGGER/JLink/JLinkExe, /usr/bin/JLinkExe
  • macOS: /Applications/SEGGER/JLink/JLinkExe

Flashing

# After building and syncing artifacts:
west env flash artifacts/build/zephyr/zephyr.hex

# Specify J-Link device explicitly:
west env flash artifacts/build/zephyr/zephyr.hex -- --device nRF52840_xxAA

west env flash automatically calls west env sync --back if workspace_mode is sync or copy, so you do not need to run sync separately.

TCP GDB server mode

For debugging inside the container, start a J-Link GDB server on the host and connect from a container-side GDB session over TCP.

jlink:
  mode: tcp-server
# Start GDB server (blocks until killed)
west env debug nRF52840_xxAA

# In another terminal or inside the container:
arm-none-eabi-gdb zephyr.elf
(gdb) target remote host.docker.internal:2331

The default GDB port is 2331.

Windows-specific notes

  • J-Link for Windows installs as JLink.exe and JLinkExe.exe (both probed).
  • The board connects via USB to the Windows host — no passthrough into any VM or WSL instance required.
  • Build artifacts are synced to a Windows path by west env sync --back and flashed directly from there.

Disabling flash

jlink:
  mode: none

west env flash and west env debug will exit with an error when mode: none. Use this when you flash via a different tool (e.g. OpenOCD, pyOCD, or a custom runner script).