add event-driven framework

see examples/event_driven_at_module and examples/event_driven_hello_world, demo project: TencentOS-tiny\board\TencentOS_tiny_EVB_MX\KEIL\event_driven_hello_world

kernel/evtdrv/tos_evtdrv_sys.c

@@ -0,0 +1,66 @@
+#include "tos_evtdrv.h"
+
+#if TOS_CFG_EVENT_DRIVEN_EN > 0u
+
+__API__ evtdrv_err_t tos_evtdrv_sys_init(evtdrv_task_entry_t tasks[], evtdrv_ttb_sz_t task_table_size, k_evtdrv_poll_t poll)
+{
+    evtdrv_err_t err;
+
+    evtdrv_task_table       = &tasks[0];
+    evtdrv_task_table_size  = task_table_size;
+
+    evtdrv_poll                 = poll;
+
+#if TOS_CFG_MMHEAP_EN > 0
+    mmheap_init(k_mmheap_pool, TOS_CFG_MMHEAP_POOL_SIZE);
+#else
+    return EVTDRV_ERR_MMHEAP_NOT_ENABLED;
+#endif
+
+    err = evtdrv_event_init();
+    if (err != EVTDRV_ERR_NONE) {
+        return err;
+    }
+
+    evtdrv_msg_init();
+
+    evtdrv_task_init();
+
+    return EVTDRV_ERR_NONE;
+}
+
+__STATIC__ void evtdrv_sys_run(void)
+{
+    evtdrv_event_flag_t event_flag = TOS_EVTDRV_EVENT_NONE;
+    evtdrv_task_id_t task_id = TOS_EVTDRV_TASK_ID_NONE;
+
+    evtdrv_timer_update();
+
+    if (evtdrv_poll) {
+        evtdrv_poll();
+    }
+
+    event_flag = evtdrv_event_fetch(&task_id);
+    if (event_flag != TOS_EVTDRV_EVENT_NONE) {
+        evtdrv_curr_task = task_id;
+        event_flag = (EVTDRV_TASK_ID2TASK(task_id))(event_flag);
+        evtdrv_curr_task = TOS_EVTDRV_TASK_ID_NONE;
+
+        // after task process, event that the task handled is returned.
+        tos_evtdrv_event_reset(task_id, event_flag);
+    } else {
+#if TOS_CFG_PWR_MGR_EN > 0u
+        pm_power_manager();
+#endif
+    }
+}
+
+__API__ void tos_evtdrv_sys_start(void)
+{
+    while (K_TRUE) {
+        evtdrv_sys_run();
+    }
+}
+
+#endif
+