feat(bt): Add Kconfig option to build the BT OSAL conditionally

components/bt/ble_profiles/common/Kconfig.in

@@ -1,6 +1,7 @@
 config BT_PRF_TASK_ENABLED
     bool "Enable the shared BLE profile task (event queue worker)"
     depends on BT_ENABLED
+    select BT_OSAL_ENABLED
     default n
     help
         Build the shared BLE profile task: a single process-wide event queue

components/bt/common/CMakeLists.txt

@@ -143,9 +143,14 @@ list(APPEND bt_common_srcs
     "${CMAKE_CURRENT_LIST_DIR}/osi/osi.c"
     "${CMAKE_CURRENT_LIST_DIR}/osi/semaphore.c"
     "${CMAKE_CURRENT_LIST_DIR}/ble_log/deprecated/ble_log_spi_out.c"
-    "${CMAKE_CURRENT_LIST_DIR}/osal/src/bt_osal_freertos.c"
 )
 
+if(CONFIG_BT_OSAL_ENABLED)
+    list(APPEND bt_common_srcs
+        "${CMAKE_CURRENT_LIST_DIR}/osal/src/bt_osal_freertos.c"
+    )
+endif()
+
 list(APPEND bt_common_include_dirs
     "${CMAKE_CURRENT_LIST_DIR}/osi/include"
     "${CMAKE_CURRENT_LIST_DIR}/api/include/api"

components/bt/common/Kconfig.in

@@ -24,8 +24,22 @@ config BT_BLE_HOST_ALLOW_SUB_SPEC_MIN_CONN_INT
 menu "OSAL (OS abstraction layer)"
     depends on BT_ENABLED
 
+    config BT_OSAL_ENABLED
+        bool "Enable the Bluetooth OS abstraction layer"
+        default n
+        help
+            Build the Bluetooth OS abstraction layer (bt_osal): a host-agnostic
+            wrapper over the OS primitives the Bluetooth stack and the BLE
+            profiles rely on — event queues, mutexes, semaphores, callouts
+            (one-shot timers), time conversion and critical sections.
+
+            Disable to leave the OSAL sources out of the build when nothing
+            uses them. A component that relies on the OSAL should
+            "select BT_OSAL_ENABLED" in its own Kconfig.
+
     config BT_OSAL_USE_ESP_TIMER
         bool "Use esp_timer to implement the OSAL callout"
+        depends on BT_OSAL_ENABLED
         default y
         help
             Use esp_timer instead of the FreeRTOS software timer to implement the OSAL

components/bt/common/osal/include/bt_osal_freertos.h

@@ -128,6 +128,7 @@ uint32_t bt_osal_freertos_hw_enter_critical(void);
 
 void bt_osal_freertos_hw_exit_critical(uint32_t ctx);
 
+#if CONFIG_BT_OSAL_ENABLED
 /**
  * @brief Allocate and populate the OSAL function table
  *
@@ -140,6 +141,15 @@ void bt_osal_freertos_funcs_init(void);
  * @brief Free the OSAL function table allocated by bt_osal_freertos_funcs_init()
  */
 void bt_osal_freertos_funcs_deinit(void);
+#else
+/* The OSAL implementation is not built. The hosts bring the function table up
+ * and down unconditionally during their init/deinit, so keep those two entry
+ * points available as no-ops instead of making every caller guard them. */
+
+static inline void bt_osal_freertos_funcs_init(void) {}
+
+static inline void bt_osal_freertos_funcs_deinit(void) {}
+#endif /* CONFIG_BT_OSAL_ENABLED */
 
 /**
  * @brief Get the OSAL function table

components/bt/test_apps/basic_unit_test/sdkconfig.defaults

@@ -1,3 +1,4 @@
 CONFIG_BT_ENABLED=y
+CONFIG_BT_OSAL_ENABLED=y
 CONFIG_BT_PRF_TASK_ENABLED=y
 CONFIG_ESP_TASK_WDT_CHECK_IDLE_TASK_CPU0=n