zynq linux调用HLS IP核的虚拟地址和物理地址问题

上一节zynq linux调用HLS IP核
中讲了如何通过UIO在zynq linux开发中调用HLS IP核，但是那个例子中只涉及到了AXI Lite接口，没有内存中虚拟地址和物理地址的问题，本节讲述如何在linux上解决该问题。
我们知道，在PL端访问ARM的DDR时，采用的是物理地址，然而在Linux上的应用程序，一般采用虚拟地址，因此zynq上linux的开发就必须解决这一问题。
本次实验，在HLS中实现了一个采用m_axi接口的向量加法IP核：
该m_axi接口与AXI HP口相连，直接读取PS端的DDR，具体功能为
读取100个a数组元素，读取100个b数组元素，然后对应元素相加，得到的100个和再写回DDR中指定的位置。
整个开发过程与上一节类似，唯一的不同就是最后的应用程序，代码如下：

/*
 * Copyright (c) 2012 Xilinx, Inc.  All rights reserved.
 *
 * Xilinx, Inc.
 * XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS" AS A
 * COURTESY TO YOU.  BY PROVIDING THIS DESIGN, CODE, OR INFORMATION AS
 * ONE POSSIBLE   IMPLEMENTATION OF THIS FEATURE, APPLICATION OR
 * STANDARD, XILINX IS MAKING NO REPRESENTATION THAT THIS IMPLEMENTATION
 * IS FREE FROM ANY CLAIMS OF INFRINGEMENT, AND YOU ARE RESPONSIBLE
 * FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE FOR YOUR IMPLEMENTATION.
 * XILINX EXPRESSLY DISCLAIMS ANY WARRANTY WHATSOEVER WITH RESPECT TO
 * THE ADEQUACY OF THE IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO
 * ANY WARRANTIES OR REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE
 * FROM CLAIMS OF INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 */
#include<stdio.h>
#include<unistd.h>
#include<sys/mman.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include"xadder.h"
#define A_BASE_ADDR 0x05000000
#define B_BASE_ADDR 0x06000000
#define C_BASE_ADDR 0X07000000
#define SIZE 4096
int main()
{
    XAdder add_inst;
    int i;
    int devmem;
    int *a_addr;
    int *b_addr;
    int *c_addr;
    devmem = open("/dev/mem", O_RDWR | O_SYNC);
    if(devmem==-1)
    	printf("open /dev/mem failed\n");
    a_addr=(int*)mmap(0,SIZE*sizeof(int),PROT_READ|PROT_WRITE,MAP_SHARED,devmem,A_BASE_ADDR);
    if(a_addr == MAP_FAILED)
    	printf("a_addr map failed\n");
    b_addr=(int*)mmap(0,SIZE*sizeof(int),PROT_READ|PROT_WRITE,MAP_SHARED,devmem,B_BASE_ADDR);
    if(b_addr == MAP_FAILED)
        	printf("b_addr map failed\n");
    c_addr=(int*)mmap(0,SIZE*sizeof(int),PROT_READ|PROT_WRITE,MAP_SHARED,devmem,C_BASE_ADDR);
    if(c_addr == MAP_FAILED)
        	printf("c_addr map failed\n");
    for(i=0;i<100;i++)
    {
    	*(a_addr+i)=2*i;
    	*(b_addr+i)=100-i;
    	*(c_addr+i)=0;
    }
    printf("test start\n");
    if(XST_SUCCESS!=XAdder_Initialize(&add_inst,"adder")){
    	printf("adder init error\n");
    	return -1;
    }
    XAdder_Set_a_r(&add_inst,(u32)A_BASE_ADDR);
    XAdder_Set_b_r(&add_inst,(u32)B_BASE_ADDR);
    XAdder_Set_c_r(&add_inst,(u32)C_BASE_ADDR);
    XAdder_Start(&add_inst);
    while(!XAdder_IsDone(&add_inst));
    XAdder_Release(&add_inst);
    printf("PL compute finished\n");
    for(i=0;i<100;i++)
    	printf("%d+%d=%d\n",*(a_addr+i),*(b_addr+i),*(c_addr+i));
    printf("end\n");
    return 0;
}