ports/zephyr: Switch BLE to extmod/zephyr_ble integration.

extmod/zephyr_ble/hal/zephyr_ble_timer.h

@@ -31,6 +31,11 @@
 #include <stdint.h>
 #include <stdbool.h>
 
+#ifdef __ZEPHYR__
+// Native Zephyr: use real kernel types
+#include <zephyr/kernel.h>
+#else
+
 // Zephyr k_timer abstraction layer for MicroPython
 // Uses polling-based timer mechanism (cooperative scheduling)
 
@@ -61,12 +66,14 @@ void k_timer_stop(struct k_timer *timer);
 // Note: K_MSEC, K_NO_WAIT, K_FOREVER are defined in zephyr_ble_work.h
 // Note: k_yield() is defined in zephyr_ble_kernel.h
 
-// Called by MicroPython scheduler to process timer callbacks
-void mp_bluetooth_zephyr_timer_process(void);
-
 // Check if two timeouts are equal
 static inline bool K_TIMEOUT_EQ(k_timeout_t a, k_timeout_t b) {
     return a.ticks == b.ticks;
 }
 
+#endif // __ZEPHYR__
+
+// Called by MicroPython scheduler to process timer callbacks
+void mp_bluetooth_zephyr_timer_process(void);
+
 #endif // MICROPY_INCLUDED_EXTMOD_ZEPHYR_BLE_HAL_ZEPHYR_BLE_TIMER_H

ports/rp2/CMakeLists.txt

@@ -84,6 +84,9 @@ endif()
 list(APPEND GIT_SUBMODULES lib/mbedtls)
 list(APPEND GIT_SUBMODULES lib/tinyusb)
 
+# Workaround for pico-sdk host toolchain issue, see directory for details
+list(APPEND CMAKE_MODULE_PATH "${MICROPY_PORT_DIR}/tools_patch")
+
 # Include component cmake fragments
 include(${MICROPY_DIR}/py/py.cmake)
 include(${MICROPY_DIR}/extmod/extmod.cmake)
@@ -259,6 +262,13 @@ elseif(PICO_RISCV)
     )
 endif()
 
+# When a board variant explicitly disables threading, override mpconfigport.h default
+if(DEFINED MICROPY_PY_THREAD AND NOT MICROPY_PY_THREAD)
+    target_compile_definitions(${MICROPY_TARGET} PRIVATE
+        MICROPY_PY_THREAD=0
+    )
+endif()
+
 # Use our custom pico_float_micropython float implementation.  This is needed for two reasons:
 # - to fix inf handling in pico-sdk's __wrap___aeabi_fadd();
 # - so we can use our own libm functions, to fix inaccuracies in the pico-sdk versions.
@@ -325,25 +335,47 @@ if (MICROPY_PY_LWIP)
 endif()
 
 if(MICROPY_PY_BLUETOOTH)
+    # Add shared HCI infrastructure for all BLE stacks (BTstack, NimBLE, Zephyr)
+    # Provides common polling, scheduling, and controller interface (WEAK overrides)
     list(APPEND MICROPY_SOURCE_PORT mpbthciport.c)
+
     target_compile_definitions(${MICROPY_TARGET} PRIVATE
         MICROPY_PY_BLUETOOTH=1
         MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS=1
         MICROPY_PY_BLUETOOTH_ENABLE_CENTRAL_MODE=1
     )
+    # Interlock requires threading support for mp_thread_get_state/set_state
+    if(NOT DEFINED MICROPY_PY_THREAD OR MICROPY_PY_THREAD)
+        target_compile_definitions(${MICROPY_TARGET} PRIVATE
+            MICROPY_PY_BLUETOOTH_USE_SYNC_EVENTS_WITH_INTERLOCK=1
+            MICROPY_PY_BLUETOOTH_SYNC_EVENT_STACK_SIZE=2048
+        )
+    endif()
 endif()
 
 if (MICROPY_PY_BLUETOOTH_CYW43)
     target_compile_definitions(${MICROPY_TARGET} PRIVATE
         CYW43_ENABLE_BLUETOOTH=1
         MICROPY_PY_BLUETOOTH_CYW43=1
+        CYW43_INCLUDE_LEGACY_F1_OVERFLOW_WORKAROUND_VARIABLES=1
+    )
+
+    # Add CYW43 external pin support (needed for LED and other CYW43 GPIO pins)
+    list(APPEND MICROPY_SOURCE_PORT
+        machine_pin_cyw43.c
     )
 
     if (MICROPY_BLUETOOTH_BTSTACK)
+        # BTstack uses SPI/SDIO BT transport
         target_link_libraries(${MICROPY_TARGET}
             pico_btstack_hci_transport_cyw43
         )
     endif()
+
+    if (MICROPY_BLUETOOTH_ZEPHYR)
+        # Zephyr BLE uses CYW43 SPI btbus (same as BTstack)
+        # HCI transport files added in MICROPY_BLUETOOTH_ZEPHYR section above
+    endif()
 endif()
 
 if (MICROPY_BLUETOOTH_BTSTACK)
@@ -387,6 +419,53 @@ if(MICROPY_BLUETOOTH_NIMBLE)
     list(APPEND MICROPY_INC_CORE ${NIMBLE_INCLUDE})
 endif()
 
+if(MICROPY_BLUETOOTH_ZEPHYR)
+    list(APPEND GIT_SUBMODULES lib/zephyr)
+    if(NOT UPDATE_SUBMODULES AND NOT EXISTS ${MICROPY_DIR}/lib/zephyr/subsys/bluetooth/host/hci_core.c)
+        message(FATAL_ERROR " zephyr not initialized.\n Run 'make BOARD=${MICROPY_BOARD} submodules'")
+    endif()
+
+    # CYW43 controller functions provided by pico-sdk via WEAK overrides
+    if (MICROPY_PY_NETWORK_CYW43)
+        list(APPEND MICROPY_SOURCE_PORT mpzephyrport_rp2.c)  # Full CYW43 HCI transport
+    else()
+        list(APPEND MICROPY_SOURCE_PORT mpzephyrport_rp2_stub.c)  # Minimal HCI stub
+    endif()
+
+    include(${MICROPY_DIR}/extmod/zephyr_ble/zephyr_ble.cmake)
+    target_link_libraries(${MICROPY_TARGET} micropy_extmod_zephyr_ble)
+
+    # Link CMSIS headers to Zephyr BLE (provides __enable_irq, __disable_irq, __ISB, __get_PRIMASK)
+    # These intrinsics are required by Zephyr's arch/arm/asm_inline_gcc.h
+    if(TARGET cmsis_core_headers)
+        target_link_libraries(micropy_extmod_zephyr_ble INTERFACE cmsis_core_headers)
+    endif()
+
+    # Define port-specific macro for cmsis_core.h stub header
+    target_compile_definitions(micropy_extmod_zephyr_ble INTERFACE __ZEPHYR_BLE_RP2_PORT__)
+
+    get_target_property(ZEPHYR_INCLUDE micropy_extmod_zephyr_ble INTERFACE_INCLUDE_DIRECTORIES)
+    list(APPEND MICROPY_INC_CORE ${ZEPHYR_INCLUDE})
+
+    # Add Zephyr BLE sources for QSTR/root pointer scanning
+    get_target_property(ZEPHYR_BLE_SOURCES micropy_extmod_zephyr_ble INTERFACE_SOURCES)
+    list(APPEND MICROPY_SOURCE_QSTR ${ZEPHYR_BLE_SOURCES})
+
+    target_compile_definitions(${MICROPY_TARGET} PRIVATE
+        MICROPY_BLUETOOTH_ZEPHYR=1
+        MICROPY_PY_BLUETOOTH_ENABLE_L2CAP_CHANNELS=1
+    )
+
+    # MICROPY_PY_BLUETOOTH_USE_ZEPHYR_HCI calls mp_bluetooth_hci_controller_init()
+    # before bt_enable(). For CYW43, HCI transport is initialized via
+    # bt_hci_transport_setup() which is called by bt_enable().
+    if (NOT MICROPY_PY_NETWORK_CYW43)
+        target_compile_definitions(${MICROPY_TARGET} PRIVATE
+            MICROPY_PY_BLUETOOTH_USE_ZEPHYR_HCI=1
+        )
+    endif()
+endif()
+
 # tinyusb helper
 target_include_directories(${MICROPY_TARGET} PRIVATE
     ${MICROPY_DIR}/shared/tinyusb/
@@ -408,15 +487,35 @@ if (MICROPY_PY_NETWORK_CYW43)
     )
     endif()
 
-    list(APPEND MICROPY_SOURCE_PORT
-        machine_pin_cyw43.c
-    )
+    # Override cyw43_malloc/free to use MicroPython's tracked allocator.
+    # This is critical because the pico-sdk's default uses C malloc which
+    # panics with "Out of memory" during BT firmware download.
+    # The compile definitions are set on cyw43_driver which is an INTERFACE
+    # library, so they propagate to all targets that link it.
+    if(TARGET cyw43_driver)
+        target_compile_definitions(cyw43_driver INTERFACE
+            cyw43_malloc=m_tracked_calloc_wrapper
+            cyw43_free=m_tracked_free
+        )
+        # Force-include header with function declarations for the above.
+        # Use generator expression to only apply to C files, not assembly.
+        target_compile_options(cyw43_driver INTERFACE
+            $<$<COMPILE_LANGUAGE:C>:-include${MICROPY_PORT_DIR}/cyw43_mp_malloc.h>
+        )
+    endif()
 
+    # Link CYW43 WiFi driver (for both BTstack and Zephyr BLE)
     target_link_libraries(${MICROPY_TARGET}
         cyw43_driver_picow
     )
+
+    # Port dir must come before pico_cyw43_driver/include so MicroPython's
+    # cyw43_configport.h is found first (the pico-SDK version defines
+    # CYW43_THREAD_ENTER as a function call requiring cyw43_arch linkage).
     target_include_directories(${MICROPY_TARGET} PRIVATE
+        "${MICROPY_PORT_DIR}"
         ${MICROPY_DIR}/lib/cyw43-driver/
+        ${PICO_SDK_PATH}/src/rp2_common/pico_cyw43_driver/include
     )
 
 endif()

ports/rp2/Makefile

@@ -60,6 +60,10 @@ ifdef MICROPY_C_HEAP_SIZE
 CMAKE_ARGS += -DMICROPY_C_HEAP_SIZE=$(MICROPY_C_HEAP_SIZE)
 endif
 
+ifdef MICROPY_BLUETOOTH_ZEPHYR
+CMAKE_ARGS += -DMICROPY_BLUETOOTH_ZEPHYR=1
+endif
+
 HELP_PICO_SDK_SUBMODULE ?= "\033[1;31mError: pico-sdk submodule is not initialized.\033[0m Run 'make submodules'"
 HELP_BUILD_ERROR ?= "See \033[1;31mhttps://github.com/micropython/micropython/wiki/Build-Troubleshooting\033[0m"
 

ports/rp2/boards/RPI_PICO2_W/mpconfigboard.h

@@ -7,15 +7,28 @@
 #define MICROPY_PY_NETWORK_HOSTNAME_DEFAULT     "Pico2W"
 
 // CYW43 driver configuration.
+// Use #ifndef guards as pico-SDK also defines these
+#ifndef CYW43_USE_SPI
 #define CYW43_USE_SPI (1)
+#endif
+#ifndef CYW43_LWIP
 #define CYW43_LWIP (1)
+#endif
+#ifndef CYW43_GPIO
 #define CYW43_GPIO (1)
+#endif
+#ifndef CYW43_SPI_PIO
 #define CYW43_SPI_PIO (1)
+#endif
 
 // For debugging mbedtls - also set
 // Debug level (0-4) 1=warning, 2=info, 3=debug, 4=verbose
 // #define MODUSSL_MBEDTLS_DEBUG_LEVEL 1
 
+// BLE UART for CYW43 Bluetooth controller (UART0)
+#define MICROPY_HW_BLE_UART_ID (0)
+#define MICROPY_HW_BLE_UART_BAUDRATE (115200)
+
 #define MICROPY_HW_PIN_EXT_COUNT    CYW43_WL_GPIO_COUNT
 
 int mp_hal_is_pin_reserved(int n);

ports/rp2/boards/RPI_PICO2_W/mpconfigvariant_zephyr_ble.cmake

@@ -0,0 +1,18 @@
+# Zephyr BLE variant for Pico 2 W (cooperative polling, no FreeRTOS)
+# Build with: make BOARD=RPI_PICO2_W BOARD_VARIANT=zephyr_ble
+
+# RP2350 platform (normally set by the default mpconfigvariant.cmake)
+set(PICO_PLATFORM "rp2350")
+
+# Disable threading - use cooperative polling instead of FreeRTOS tasks
+set(MICROPY_PY_THREAD OFF)
+
+# Allocate 16KB C heap for GATT service/UUID allocations
+set(MICROPY_C_HEAP_SIZE 16384)
+
+# Override bluetooth stack selection
+set(MICROPY_BLUETOOTH_BTSTACK OFF)
+set(MICROPY_BLUETOOTH_ZEPHYR ON)
+
+# Force fetch picotool from git (version mismatch workaround)
+set(PICOTOOL_FORCE_FETCH_FROM_GIT ON)

ports/rp2/boards/RPI_PICO_W/mpconfigvariant_zephyr_ble.cmake

@@ -0,0 +1,16 @@
+# Zephyr BLE variant for Pico W (cooperative polling, no FreeRTOS)
+# Build with: make BOARD=RPI_PICO_W BOARD_VARIANT=zephyr_ble
+message(STATUS "Loading Zephyr BLE polling variant for Pico W")
+
+# Disable threading - use cooperative polling instead of FreeRTOS tasks
+set(MICROPY_PY_THREAD OFF)
+
+# Allocate 16KB C heap for GATT service/UUID allocations
+set(MICROPY_C_HEAP_SIZE 16384)
+
+# Override bluetooth stack selection
+set(MICROPY_BLUETOOTH_BTSTACK OFF)
+set(MICROPY_BLUETOOTH_ZEPHYR ON)
+
+# Force fetch picotool from git (version mismatch workaround)
+set(PICOTOOL_FORCE_FETCH_FROM_GIT ON)

ports/rp2/cyw43_btfw_43439_extern.h

@@ -0,0 +1,8 @@
+// Stub header to declare BT firmware data as extern
+// (actual definition is in cybt_shared_bus.c)
+extern const unsigned char cyw43_btfw_43439[];
+extern const unsigned int cyw43_btfw_43439_len;
+
+// Alias names used in cyw43_bthci_uart.c
+#define btfw_data cyw43_btfw_43439
+#define btfw_len cyw43_btfw_43439_len

ports/rp2/cyw43_bthci_uart_wrapper.c

@@ -0,0 +1,68 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2025 MicroPython Contributors
+ *
+ * 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.
+ */
+
+// Wrapper to include cyw43_bthci_uart.c with proper CYW43 BT configuration
+//
+// NOTE: The BT firmware data is defined in cybt_shared_bus.c (part of
+// cyw43_driver_picow library). To avoid duplicate definitions, we declare
+// the firmware data as extern here and skip including the firmware header.
+
+// Include MicroPython HAL
+#include "py/mphal.h"
+
+// Force-define CYW43 BT UART transport before any CYW43 includes
+#ifdef CYW43_ENABLE_BLUETOOTH_OVER_UART
+#undef CYW43_ENABLE_BLUETOOTH_OVER_UART
+#endif
+#define CYW43_ENABLE_BLUETOOTH_OVER_UART 1
+
+// Use stub firmware header that declares data as extern
+#define CYW43_BT_FIRMWARE_INCLUDE_FILE "cyw43_btfw_43439_extern.h"
+
+// Define MAC address index for BDADDR
+#ifndef CYW43_HAL_MAC_BDADDR
+#define CYW43_HAL_MAC_BDADDR MP_HAL_MAC_BDADDR
+#endif
+
+// Define other BT config that should come from cyw43_configport.h
+#ifndef CYW43_PIN_BT_REG_ON
+#define CYW43_PIN_BT_REG_ON                 (0)
+#endif
+#ifndef CYW43_PIN_BT_CTS
+#define CYW43_PIN_BT_CTS                    (2)
+#endif
+#ifndef CYW43_PIN_BT_HOST_WAKE
+#define CYW43_PIN_BT_HOST_WAKE              (3)
+#endif
+#ifndef CYW43_PIN_BT_DEV_WAKE
+#define CYW43_PIN_BT_DEV_WAKE               (4)
+#endif
+#ifndef CYW43_HAL_UART_READCHAR_BLOCKING_WAIT
+#define CYW43_HAL_UART_READCHAR_BLOCKING_WAIT mp_event_handle_nowait()
+#endif
+
+// Include the actual implementation
+#include "../../lib/cyw43-driver/src/cyw43_bthci_uart.c"