[bsp] Add LonganNano board support

- Get drivers from upstream
- Fix no context switching after interrupt issue

[libcpu] Get RISC-V support from upstream
[drv] Add device IPC and common serial device driver from upstream

Author: onelife

README.md

@@ -62,6 +62,7 @@ I hope this project will release the power of multitasking on Arduino platform.
 | --- | --- | --- |
 | SAM | ARM Cortex-M3 | Tested with Arduino Due |
 | SAMD | ARM Cortex-M0+ | Tested with Arduino MKRZero |
+| GD32V | Bumblebee (RV32IMAC) | Tested with Longan Nano |
 
 
 ## License  ##

library.properties

@@ -1,11 +1,11 @@
 name=RT-Thread
-version=0.7.8
+version=0.8.0
 author=onelife <[email protected]>, Bernard Xiong <[email protected]>
 maintainer=onelife <[email protected]>
 sentence=Real Time Operating System porting for Arduino SAM and SAMD boards
 paragraph=RT-Thread is an open source IoT operating system from China, which has strong scalability: from a tiny kernel running on a tiny core, for example ARM Cortex-M0, or Cortex-M3/4/7, to a rich feature system running on MIPS32, ARM Cortex-A8, ARM Cortex-A9 DualCore etc.
 category=Timing
 url=https://github.com/onelife/Arduino_RT-Thread_Library
-architectures=sam,samd
+architectures=sam,samd,gd32v
 licence=Apache License 2.0
 includes=rtt.h

src/bsp/LonganNano/drv_tick.c

@@ -0,0 +1,83 @@
+/***************************************************************************//**
+ * @file    drv_tick.cpp
+ * @brief   Arduino RT-Thread library RISC-V tick driver
+ * @author  onelife <onelife.real[at]gmail.com>
+ ******************************************************************************/
+/* Includes ------------------------------------------------------------------*/
+#include "include/rtthread.h"
+
+#if defined(BOARD_SIPEED_LONGAN_NANO)
+
+#include "bsp/bsp.h"
+
+/***************************************************************************//**
+ * @addtogroup LonganNano
+ * @{
+ ******************************************************************************/
+
+/* Private typedef -----------------------------------------------------------*/
+/* Private define ------------------------------------------------------------*/
+/* Private function prototypes -----------------------------------------------*/
+/* Private constants ---------------------------------------------------------*/
+/* Private variables ---------------------------------------------------------*/
+static rt_uint64_t overflow = 0;
+
+/* Private functions ---------------------------------------------------------*/
+
+/* Public functions ----------------------------------------------------------*/
+rt_err_t bsp_hw_tick_init(void) {
+    rt_uint64_t ticks;
+
+    /* get counter value */
+    ticks = *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIME);
+    /* set compare value */
+    if ((ticks + (TIMER_FREQ / RT_TICK_PER_SECOND)) < ticks) {
+        /* overflow */
+        overflow = ticks + (TIMER_FREQ / RT_TICK_PER_SECOND);
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIMECMP) = (rt_uint64_t)(-1);
+    } else {
+        overflow = 0;
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIMECMP) = \
+            ticks + (TIMER_FREQ / RT_TICK_PER_SECOND);
+
+    }
+    *(rt_uint32_t *)(TIMER_CTRL_ADDR + TIMER_MSIP) = 1;
+    eclic_irq_enable(CLIC_INT_TMR, 0, 0);
+
+    return RT_EOK;
+}
+
+/* system timer ISR */
+void eclic_mtip_handler(void) {
+    rt_uint64_t ticks;
+
+    /* update compare value */
+    if (overflow > 0) {
+        /* overflow 2nd half */
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIME) = 0;
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIMECMP) = overflow;
+        overflow = 0;
+        return;
+    }
+
+    ticks = *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIME);
+    if ((ticks + (TIMER_FREQ / RT_TICK_PER_SECOND)) < ticks) {
+        /* overflow */
+        overflow = ticks + (TIMER_FREQ / RT_TICK_PER_SECOND);
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIMECMP) = \
+            (rt_uint64_t)(-1);
+    } else {
+        overflow = 0;
+        *(rt_uint64_t *)(TIMER_CTRL_ADDR + TIMER_MTIMECMP) = \
+            ticks + (TIMER_FREQ / RT_TICK_PER_SECOND);
+    }
+    rt_interrupt_enter();
+    rt_tick_increase();
+    rt_interrupt_leave();
+}
+
+/***************************************************************************//**
+ * @}
+ ******************************************************************************/
+
+#endif /* defined(BOARD_SIPEED_LONGAN_NANO) */

src/bsp/LonganNano/drv_tick.h

@@ -0,0 +1,17 @@
+/***************************************************************************//**
+ * @file    drv_tick.h
+ * @brief   Arduino RT-Thread library RISC-V tick driver header
+ * @author  onelife <onelife.real[at]gmail.com>
+ ******************************************************************************/
+#ifndef __LONGAN_NANO_DRV_TICK_H__
+#define __LONGAN_NANO_DRV_TICK_H__
+
+/* Includes ------------------------------------------------------------------*/
+/* Exported defines ----------------------------------------------------------*/
+/* Exported types ------------------------------------------------------------*/
+/* Exported constants --------------------------------------------------------*/
+
+/* Exported functions ------------------------------------------------------- */
+rt_err_t bsp_hw_tick_init(void);
+
+#endif /* __LONGAN_NANO_DRV_TICK_H__ */