add support for GD32F310G-START

board/GD32F310G_START/BSP/Src/main.c

@@ -0,0 +1,37 @@
+#include "mcu_init.h"
+#include "tos_shell.h"
+
+#define APPLICATION_TASK_STK_SIZE       0x100
+k_task_t application_task;
+uint8_t application_task_stk[APPLICATION_TASK_STK_SIZE];
+static char gs_cmd_buffer[32];
+
+__attribute__ ((__weak__)) void application_entry(void *arg)
+{
+    while (1) {
+        gpio_bit_toggle(LED_GPIO_Port, LED_Pin);
+        tos_task_delay(1000);
+    }
+}
+
+static void board_shell_output_t(const char ch)
+{
+    if (ch == '\n')
+    {
+        while(RESET == usart_flag_get(USART0, USART_FLAG_TBE));
+        usart_data_transmit(USART0, '\r');
+    }
+    while(RESET == usart_flag_get(USART0, USART_FLAG_TBE));
+    usart_data_transmit(USART0, ch);
+}
+
+int main(void)
+{
+    board_init();
+    printf("Welcome to TencentOS tiny(%s)\r\n", TOS_VERSION);
+    tos_knl_init();
+    tos_task_create(&application_task, "application_task", application_entry, NULL, 4, application_task_stk, APPLICATION_TASK_STK_SIZE, 0);
+    tos_shell_init(gs_cmd_buffer, sizeof(gs_cmd_buffer), board_shell_output_t, NULL);
+    tos_knl_start();
+}
+