Add initial board support for nRF54LM20 DK

Author: gab-k

docs/reference/boards.rst

@@ -221,6 +221,7 @@ nrf52840dk                   Nordic nRF52840DK                      nrf       ht
 nrf52840dongle               Nordic nRF52840 Dongle                 nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF52840-Dongle
 nrf5340dk                    Nordic nRF5340 DK                      nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF5340-DK
 nrf54h20dk                   Nordic nRF54H20 DK                     nrf       https://www.nordicsemi.com/Software-and-Tools/Development-Kits/nRF5340-DK
+nrf54lm20dk                  Nordic nRF54LM20 DK                    nrf       https://www.nordicsemi.com/Products/Development-hardware/nRF54LM20-DK
 ===========================  =====================================  ========  ==============================================================================  ======
 
 Raspberry Pi

hw/bsp/BoardPresets.json

@@ -470,6 +470,10 @@
       "name": "nrf54h20dk",
       "inherits": "default"
     },
+    {
+      "name": "nrf54lm20dk",
+      "inherits": "default"
+    },
     {
       "name": "nutiny_nuc126v",
       "inherits": "default"
@@ -1563,6 +1567,11 @@
       "description": "Build preset for the nrf54h20dk board",
       "configurePreset": "nrf54h20dk"
     },
+    {
+      "name": "nrf54lm20dk",
+      "description": "Build preset for the nrf54lm20dk board",
+      "configurePreset": "nrf54lm20dk"
+    },
     {
       "name": "nutiny_nuc126v",
       "description": "Build preset for the nutiny_nuc126v board",
@@ -3711,6 +3720,19 @@
         }
       ]
     },
+    {
+      "name": "nrf54lm20dk",
+      "steps": [
+        {
+          "type": "configure",
+          "name": "nrf54lm20dk"
+        },
+        {
+          "type": "build",
+          "name": "nrf54lm20dk"
+        }
+      ]
+    },
     {
       "name": "nutiny_nuc126v",
       "steps": [

hw/bsp/nrf/boards/nrf54lm20dk/board.cmake

@@ -0,0 +1,11 @@
+set(MCU_VARIANT nrf54lm20a_enga)
+set(JLINK_DEVICE NRF54LM20A_M33)
+
+function(update_board TARGET)
+  target_compile_definitions(${TARGET} PUBLIC
+    CFG_EXAMPLE_VIDEO_READONLY
+    )
+  target_sources(${TARGET} PRIVATE
+#    ${NRFX_PATH}/drivers/src/nrfx_usbreg.c
+    )
+endfunction()

hw/bsp/nrf/boards/nrf54lm20dk/board.h

@@ -0,0 +1,58 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020, Ha Thach (tinyusb.org)
+ * Copyright (c) 2026, Gabriel Koppenstein
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * This file is part of the TinyUSB stack.
+ */
+
+/* metadata:
+   name: Nordic nRF54LM20 DK
+   url: https://www.nordicsemi.com/Products/Development-hardware/nRF54LM20-DK
+*/
+
+#ifndef BOARD_H_
+#define BOARD_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+#define _PINNUM(port, pin)    ((port)*32 + (pin))
+
+// LED0 active high (MOSFET-driven)
+#define LED_PIN               _PINNUM(1, 22)
+#define LED_STATE_ON          1
+
+// Button0 active low
+#define BUTTON_PIN            _PINNUM(1, 26)
+#define BUTTON_STATE_ACTIVE   0
+
+// UART20 (VCOM via debugger)
+#define UART_TX_PIN           _PINNUM(1, 16)
+#define UART_RX_PIN           _PINNUM(1, 17)
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* BOARD_H_ */

hw/bsp/nrf/boards/nrf54lm20dk/board.mk

@@ -0,0 +1,6 @@
+MCU_VARIANT = nrf54lm20a_enga
+CFLAGS += -DNRF54LM20A_ENGA_XXAA
+
+# flash using jlink
+JLINK_DEVICE = NRF54LM20A_M33
+flash: flash-jlink

hw/bsp/nrf/family.c

@@ -2,6 +2,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ * Copyright (c) 2026, Gabriel Koppenstein
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -45,7 +46,7 @@
 #include "nrfx.h"
 #include "hal/nrf_gpio.h"
 #include "nrfx_gpiote.h"
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
 #include "nrfx_power.h"
 #endif
 #include "nrfx_uarte.h"
@@ -79,13 +80,17 @@ enum {
 };
 
 // Forward USB interrupt events to TinyUSB IRQ Handler
-#if defined(NRF54H20_XXAA)
+#if defined(NRF54H20_XXAA) || defined(NRF54LM20A_ENGA_XXAA)
 #define USBD_IRQn  USBHS_IRQn
 void USBHS_IRQHandler(void) {
   tusb_int_handler(0, true);
 }
 
+#if defined(NRF54LM20A_ENGA_XXAA)
+static nrfx_uarte_t _uart_id = NRFX_UARTE_INSTANCE(20);
+#else
 static nrfx_uarte_t _uart_id = NRFX_UARTE_INSTANCE(120);
+#endif
 
 #else
 
@@ -114,7 +119,7 @@ void USBD_IRQHandler(void) {
 // We must call it within SD's SOC event handler, or set it as power event handler if SD is not enabled.
 extern void tusb_hal_nrf_power_event(uint32_t event);
 
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
 // nrf power callback, could be unused if SD is enabled or usb is disabled (board_test example)
 TU_ATTR_UNUSED static void power_event_handler(nrfx_power_usb_evt_t event) {
   tusb_hal_nrf_power_event((uint32_t) event);
@@ -133,7 +138,7 @@ static nrfx_gpiote_t _gpiote = NRFX_GPIOTE_INSTANCE(0);
 //--------------------------------------------------------------------+
 
 void board_init(void) {
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
   // stop LF clock just in case we jump from application without reset
   NRF_CLOCK->TASKS_LFCLKSTOP = 1UL;
 
@@ -186,11 +191,63 @@ void board_init(void) {
 
   //------------- USB -------------//
 #if CFG_TUD_ENABLED
+
+#if defined(NRF54LM20A_ENGA_XXAA)
+  // Start the USB voltage regulator
+  NRF_VREGUSB->TASKS_START = VREGUSB_TASKS_START_TASKS_START_Trigger;
+
+  // Request HFXO crystal clock for PCLK24M (required by USBHS core)
+  NRF_CLOCK->TASKS_XO24MSTART = CLOCK_TASKS_XO24MSTART_TASKS_XO24MSTART_Trigger;
+  while (!NRF_CLOCK->EVENTS_XO24MSTARTED) {}
+  NRF_CLOCK->EVENTS_XO24MSTARTED = 0;
+#endif
+
+#if defined(NRF54H20_XXAA)
+  // Enable the USBHS wrapper (core + PHY) before any DWC2 register access
+  NRF_USBHS->ENABLE = (USBHS_ENABLE_PHY_Enabled << USBHS_ENABLE_PHY_Pos) |
+                       (USBHS_ENABLE_CORE_Enabled << USBHS_ENABLE_CORE_Pos);
+  NRF_USBHS->TASKS_START = USBHS_TASKS_START_TASKS_START_Trigger;
+  // Brief delay for PHY PLL lock and core power-up
+  for (volatile int i = 0; i < 1000; i++) {}
+#endif
+
+#if defined(NRF54LM20A_ENGA_XXAA)
+  // Based on Zephyr usbhs_enable_core() in drivers/usb/udc/udc_dwc2_vendor_quirks.h
+  // Step 1: Power up core only (PHY not yet)
+  NRF_USBHS->ENABLE = USBHS_ENABLE_CORE_Msk;
+
+  // Step 2: Override ID=Device (bit 31), and temporarily override VBUSVALID
+  NRF_USBHS->PHY.OVERRIDEVALUES = (USBHS_PHY_OVERRIDEVALUES_ID_Device << USBHS_PHY_OVERRIDEVALUES_ID_Pos);
+  NRF_USBHS->PHY.INPUTOVERRIDE = USBHS_PHY_INPUTOVERRIDE_ID_Msk | USBHS_PHY_INPUTOVERRIDE_VBUSVALID_Msk;
+
+  // Step 3: Release PHY power-on reset by enabling PHY
+  NRF_USBHS->ENABLE = USBHS_ENABLE_PHY_Msk | USBHS_ENABLE_CORE_Msk;
+
+  // Step 4: Wait 45us for PHY clock to start
+  NRFX_DELAY_US(45);
+
+  // Step 5: Release DWC2 reset
+  NRF_USBHS->TASKS_START = USBHS_TASKS_START_TASKS_START_Trigger;
+
+  // Step 6: Wait for clock to start to avoid hang on too early register read
+  NRFX_DELAY_US(2);
+
+  // Step 7: Clear VBUSVALID override (keep ID=Device override)
+  // DWC2 is now in Non-Driving opmode; D+ pull-up will activate when DWC2 clears DCTL SftDiscon
+  NRF_USBHS->PHY.INPUTOVERRIDE = USBHS_PHY_INPUTOVERRIDE_ID_Msk;
+
+  // Barrier: USBHS wrapper (0x5005A000) and USBHSCORE (0x50020000) are separate
+  // peripheral blocks. Ensure the ENABLE/TASKS_START writes have propagated from
+  // the Cortex-M33 write buffer to hardware before anyone reads DWC2 core regs.
+  __DSB();
+
+#endif
+
   // Priorities 0, 1, 4 (nRF52) are reserved for SoftDevice
   // 2 is highest for application
   NVIC_SetPriority(USBD_IRQn, 2);
 
-#if !defined(NRF54H20_XXAA)
+#if !defined(NRF54H20_XXAA) && !defined(NRF54LM20A_ENGA_XXAA)
   // USB power may already be ready at this time -> no event generated
   // We need to invoke the handler based on the status initially
   uint32_t usb_reg;
@@ -258,7 +315,7 @@ size_t board_get_unique_id(uint8_t id[], size_t max_len) {
 
 #if defined(NRF54H20_XXAA)
   uintptr_t did_addr = (uintptr_t) NRF_FICR->BLE.ADDR;
-#elif defined(NRF5340_XXAA)
+#elif defined(NRF54LM20A_ENGA_XXAA) || defined(NRF5340_XXAA)
   uintptr_t did_addr = (uintptr_t) NRF_FICR->INFO.DEVICEID;
 #else
   uintptr_t did_addr = (uintptr_t) NRF_FICR->DEVICEID;

hw/bsp/nrf/family.cmake

@@ -10,15 +10,19 @@ if (NOT board_cmake_included)
 endif ()
 
 # toolchain set up
-if (MCU_VARIANT STREQUAL nrf5340 OR MCU_VARIANT STREQUAL nrf54h20)
+if (MCU_VARIANT STREQUAL nrf5340 OR MCU_VARIANT STREQUAL nrf54h20 OR MCU_VARIANT STREQUAL nrf54lm20a_enga)
   set(CMAKE_SYSTEM_CPU cortex-m33 CACHE INTERNAL "System Processor")
-  set(JLINK_DEVICE ${MCU_VARIANT}_xxaa_app)
+  if (NOT DEFINED JLINK_DEVICE)
+    set(JLINK_DEVICE ${MCU_VARIANT}_xxaa_app)
+  endif ()
 else ()
   set(CMAKE_SYSTEM_CPU cortex-m4 CACHE INTERNAL "System Processor")
-  set(JLINK_DEVICE ${MCU_VARIANT}_xxaa)
+  if (NOT DEFINED JLINK_DEVICE)
+    set(JLINK_DEVICE ${MCU_VARIANT}_xxaa)
+  endif ()
 endif ()
 
-if (MCU_VARIANT STREQUAL "nrf54h20")
+if (MCU_VARIANT STREQUAL "nrf54h20" OR MCU_VARIANT STREQUAL "nrf54lm20a_enga")
   set(FAMILY_MCUS NRF54 CACHE INTERNAL "")
 else ()
   set(FAMILY_MCUS NRF5X CACHE INTERNAL "")
@@ -29,7 +33,10 @@ set(CMAKE_TOOLCHAIN_FILE ${TOP}/examples/build_system/cmake/toolchain/arm_${TOOL
 #------------------------------------
 # Startup & Linker script
 #------------------------------------
-if (MCU_VARIANT STREQUAL nrf54h20)
+if (MCU_VARIANT STREQUAL nrf54lm20a_enga)
+  set(LD_FILE_GNU_DEFAULT ${CMAKE_CURRENT_LIST_DIR}/linker/${MCU_VARIANT}_xxaa_application.ld)
+  set(STARTUP_FILE_GNU ${NRFX_PATH}/mdk/gcc_startup_${MCU_VARIANT}_application.S)
+elseif (MCU_VARIANT STREQUAL nrf54h20)
   set(LD_FILE_GNU_DEFAULT ${CMAKE_CURRENT_LIST_DIR}/linker/${MCU_VARIANT}_xxaa_application.ld)
   set(STARTUP_FILE_GNU ${NRFX_PATH}/mdk/gcc_startup_${MCU_VARIANT}_application.S)
 elseif (MCU_VARIANT STREQUAL nrf5340)
@@ -52,13 +59,20 @@ function(family_add_board BOARD_TARGET)
   add_library(${BOARD_TARGET} STATIC
     ${NRFX_PATH}/helpers/nrfx_flag32_allocator.c
     ${NRFX_PATH}/drivers/src/nrfx_gpiote.c
-    ${NRFX_PATH}/drivers/src/nrfx_power.c
     ${NRFX_PATH}/drivers/src/nrfx_spim.c
     ${NRFX_PATH}/drivers/src/nrfx_uarte.c
     ${NRFX_PATH}/soc/nrfx_atomic.c
     )
 
-  if (MCU_VARIANT STREQUAL nrf54h20)
+  if (NOT FAMILY_MCUS STREQUAL "NRF54")
+    target_sources(${BOARD_TARGET} PRIVATE ${NRFX_PATH}/drivers/src/nrfx_power.c)
+  endif ()
+
+  if (MCU_VARIANT STREQUAL nrf54lm20a_enga)
+    target_sources(${BOARD_TARGET} PRIVATE
+      ${NRFX_PATH}/mdk/system_nrf54l.c
+    )
+  elseif (MCU_VARIANT STREQUAL nrf54h20)
     target_sources(${BOARD_TARGET} PRIVATE
       ${NRFX_PATH}/mdk/system_nrf54h.c
     )

hw/bsp/nrf/family.mk

@@ -4,6 +4,15 @@ NRFX_PATH = hw/mcu/nordic/nrfx
 
 include $(TOP)/$(BOARD_PATH)/board.mk
 
+ifeq (${MCU_VARIANT},nrf54lm20a_enga)
+	CPU_CORE = cortex-m33
+	CFLAGS += -DCFG_TUSB_MCU=OPT_MCU_NRF54
+	LD_FILE_DEFAULT = ${FAMILY_PATH}/linker/${MCU_VARIANT}_xxaa_application.ld
+	SRC_C += ${NRFX_PATH}/mdk/system_nrf54l.c
+	SRC_S += ${NRFX_PATH}/mdk/gcc_startup_$(MCU_VARIANT)_application.S
+	JLINK_DEVICE ?= $(MCU_VARIANT)_xxaa_app
+
+else
 ifeq (${MCU_VARIANT},nrf54h20)
 	CPU_CORE = cortex-m33
 	CFLAGS += -DCFG_TUSB_MCU=OPT_MCU_NRF54
@@ -32,6 +41,7 @@ else
 	JLINK_DEVICE ?= $(MCU_VARIANT)_xxaa
 endif
 endif
+endif
 
 CFLAGS += \
   -DNRF_APPLICATION \
@@ -70,11 +80,14 @@ SRC_C += \
 	src/portable/synopsys/dwc2/hcd_dwc2.c \
 	${NRFX_PATH}/helpers/nrfx_flag32_allocator.c \
 	${NRFX_PATH}/drivers/src/nrfx_gpiote.c \
-  ${NRFX_PATH}/drivers/src/nrfx_power.c \
   ${NRFX_PATH}/drivers/src/nrfx_spim.c \
   ${NRFX_PATH}/drivers/src/nrfx_uarte.c \
   ${NRFX_PATH}/soc/nrfx_atomic.c
 
+ifeq (,$(findstring OPT_MCU_NRF54,$(CFLAGS)))
+SRC_C += ${NRFX_PATH}/drivers/src/nrfx_power.c
+endif
+
 INC += \
   $(TOP)/$(BOARD_PATH) \
   $(TOP)/$(FAMILY_PATH)/nrfx_config \

hw/bsp/nrf/linker/nrf54lm20a_enga_xxaa_application.ld

@@ -0,0 +1,13 @@
+/* Linker script to configure memory regions. */
+
+SEARCH_DIR(.)
+/*GROUP(-lgcc -lc) not compatible with clang*/
+
+MEMORY
+{
+  FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 0x1FD000 /* Inside global RRAM0 */
+  RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 0x40000
+  RAM1 (rwx) : ORIGIN = 0x20040000, LENGTH = 0x40000
+}
+
+INCLUDE "nrf_common.ld"

hw/bsp/nrf/nrfx_config/nrfx_config_common.h

@@ -62,6 +62,9 @@
 #if defined(NRF54H20_XXAA)
 #define NRFX_UARTE120_ENABLED  1
 
+#elif defined(NRF54LM20A_ENGA_XXAA)
+#define NRFX_UARTE20_ENABLED   1
+
 #else
 
 #define NRFX_POWER_ENABLED   1