error :the trampolines not yet implemented

在Nios ii eds 9.0那里build 一个小的 project,弄了几天，老是出现这个错误：the trampolines not yet implemented! 不知道有哪位高人知道错在哪里了！我写的程序如下：错误标在main函数的大括号上：

#include <stdio.h>
#include "system.h"
#include "altera_avalon_uart_regs.h"
#include "altera_avalon_dma_regs.h"
#include "sys/alt_dma.h"
#include "alt_types.h"
int main()
{ 
    static alt_u8 tx_done;
    char txdata[]="I'm coming!";
    alt_dma_txchan tx;
    void done(void* handle,void*data)
        {
            tx_done++;
        }
    IOWR_ALTERA_AVALON_UART_CONTROL(UART_BASE,0X10000);
    IOWR_ALTERA_AVALON_UART_EOP(UART_BASE,'\0');
    tx = alt_dma_txchan_open ("/dev/dma_0");
    if (tx == NULL)
      {
          printf("failure in dma_open!");
      }
    else
      {
        if(alt_dma_txchan_ioctl(tx,ALT_DMA_SET_MODE_8,NULL))
           {
            if(alt_dma_txchan_ioctl(tx,ALT_DMA_RX_ONLY_ON ,(void*)(UART_BASE+1)))
              {
               if(alt_dma_txchan_send(tx,txdata,20,done,NULL))
                   printf("sucessful!");
               else
                   printf("failure!");
              }
           }
        while(!tx_done);
      }
      return 0;
}（错误标在这里，就这个括号）！

求救啊！