Add xiao nrf54lm20b support - #30
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cumin777 merged 13 commits intoAug 14, 2026
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First bring-up of the XIAO nRF54LM20B, built on the nrf54lm20a/cpuapp SoC target. SWD programming baseline (USB DFU / MCUboot / signed packages are follow-up work). Board definition (Zephyr): - boards/seeed/xiao_nrf54lm20b/: Kconfig, board.cmake/yml, defconfig, CPUapp / CPUflpr DTS + yaml, common and pinctrl dtsi, XIAO connector dtsi, doc/index.rst, support/openocd.cfg - boards/pm_static_xiao_nrf54lm20b_nrf54lm20a_cpuapp.yml MicroPython integration: - xiao_nrf54lm20b_manifest.py, _nrf54lm20a_cpuapp.conf/.overlay - example/boards/xiao_nrf54lm20b.py (board pin/peripheral map) - example/boards/xiao.py: nrf54lm20b dispatch branch + XiaoPDM guard Tests / docs: - example/xiao_nrf54lm20b_full_test.py - README: "XIAO nRF54LM20B (SWD baseline)" build/flash/test section Co-Authored-By: Claude <noreply@anthropic.com>
The board was named nRF54LM20B but every SoC-level file targeted nrf54lm20a. nRF54LM20B is a distinct SoC: NCS v3.3.0 ships a dedicated nrf54lm20b SoC, and Nordic's own nrf54lm20dk exposes nrf54lm20a and nrf54lm20b as separate targets. Building the 20B board on the 20A SoC also broke runtime board detection in example/boards/xiao.py, which keys off implementation._machine. Switch the whole board to nrf54lm20b: - board.yml: soc name and runner targets - Kconfig: SOC_NRF54LM20B_* under BOARD_XIAO_NRF54LM20B_NRF54LM20B_* - dtsi: <nordic/nrf54lm20b_cpuapp/cpuflpr.dtsi> - board.cmake: CONFIG_SOC_NRF54LM20B_* and openocd chipname/load proc - yaml identifiers, dts compatible/model, and the _nrf54lm20a file names - README build commands and the cpuapp qualifier OpenOCD CTRL-AP comments and nRF54LM20A/B comparison prose are kept unchanged (they describe the shared debug IP / hardware delta). Co-Authored-By: Claude <noreply@anthropic.com>
…ot config Replace the board device tree with the updated definitions from cumin777/platform-seeedboards (branch xiao_nrf54lm20b_main_integration) and add the USB CDC ACM MCUboot serial-recovery configuration. Device tree (nrf54lm20b_cpuapp_common.dtsi): - Flash layout: shipped 24 KiB no-log mcuboot + slot0 app (1784 KiB @0x6000, imgtool slot_size 0x1BE000) + slot1 loader (116 KiB) + storage (16 KiB) -- single-app-slot + loader scheme, replacing the old 68 KiB / A/B layout. - Console/shell/mcumgr moved from uart20 to the USB CDC ACM device (cdc_acm_uart on &usbhs); +zephyr,boot-mode and gpregret retention; vregusb on; LFXO load capacitance 16000. Board config: - Kconfig.defconfig: source the Zephyr CDC ACM serial defconfig and pin the Seeed app CDC VID:PID 2886:8013 / product "XIAO_NRF54LM20B" (the loader CDC is 2886:0013, owned by the pre-flashed mcuboot). - board.cmake: drop the openocd runner (USB-only flashing); jlink device names nRF54LM20A_M33 / nRF54LM20A_RV32. - New mcuboot.conf + mcuboot.overlay: MCUboot serial recovery over USB CDC ACM, button/wait/no-app entry, RSA-3072 software signing, USB_DEVICE_STACK_NEXT. - doc/index.rst: correct the nRF54LM20B description (Axon NPU). Discard support/openocd.cfg entirely. Bootloader and KMU keys are pre-flashed on devices; only the signed app image is built/flashed here (signing + flash tooling in follow-up commits). Co-Authored-By: Claude <noreply@anthropic.com>
The mcuboot.conf brought in with the platform-seeedboards DT forced BOOT_SIGNATURE_TYPE_RSA / RSA-3072, overriding the nRF54LM20B SoC default (Ed25519). The device's pre-flashed boot actually verifies Ed25519 "pure" signatures with the public key in KMU -- matching the PlatformIO flow (boards/seeed-xiao-nrf54lm20b.json signature_key_file root-ed25519.pem, pure=true) and the GitLab boot bringup (BOOT_SIGNATURE_TYPE_PURE + SIGNATURE_USING_KMU). RSA-3072 and Ed25519 are mutually exclusive, so the RSA selection would have produced images the device rejects. Switch to: BOOT_SIGNATURE_TYPE_ED25519 + BOOT_SIGNATURE_TYPE_PURE + BOOT_SIGNATURE_USING_KMU App images are signed with the mcuboot default root-ed25519.pem. Co-Authored-By: Claude <noreply@anthropic.com>
User-facing flashing for the XIAO nRF54LM20B -- no SWD/J-Link needed.
Flow: hold USER + press RESET to enter the MCUboot USB serial-recovery
loader (USB CDC VID:PID 2886:0013), then this helper auto-detects that
loader port and uploads the signed app image with `nrfutil mcumgr image
upload`. The bootloader and KMU public key are factory-flashed, so only
the signed application is transferred.
- xiao_nrf54lm20b_flash.py: pyserial-based loader-port detection
(2886:0013), firmware auto-select, optional --mtu/--port, button+reset
wait loop.
- xiao_nrf54lm20b_flash.{sh,bat}: platform wrappers (mirrors the
xiao_nrf54lm20a_flash layout).
- .gitignore: ignore __pycache__/*.pyc so helper caches aren't committed.
Prereq: pip install nrfutil (bundles pyserial).
Co-Authored-By: Claude <noreply@anthropic.com>
… .ps1 The flasher used `nrfutil mcumgr ...`, which fails on nrfutil 8.x (the subcommand is `mcu-manager`; `mcumgr` is not installed). Align with the validated flow (`nrfutil mcu-manager serial image-upload`), which also accepts a signed .bin directly. - xiao_nrf54lm20b_flash.py: switch to `mcu-manager serial image-upload` (+ reset); resolve a portable bundled nrfutil before falling back to PATH (NRFUTIL_HOME set when a bundled home is present). - xiao_nrf54lm20b_flash.ps1: new portable Windows flasher (WMI auto-detect of the 2886:0013 loader port; bundled-nrfutil resolution; zero install). - flash_usb_dfu.cmd: double-click / cmd launcher for the .ps1. The ~9 MB nrfutil binary is NOT committed -- it is bundled only in the release/delivery zip so the repo stays small. Co-Authored-By: Claude <noreply@anthropic.com>
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Add xiao nrf54lm20b support