Zynq读写SD卡

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://blog.csdn.net/jinhua1990/article/details/84100100

之前一直没有写过博客，也不知道如何开始，现在想记录一下自己做过的事情，以后回看还能记得更快。那就以此为开始吧~~~

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项目需要，要实现一个将数据写入到SD卡中的小demo，查找了一些资料，最后终于实现，将具体实现方案记录如下。

 

1.搭建Zynq硬件平台，根据开发板及自己需要设置好DDR、PL时钟、外设等，本实验要选中SD0、UART1；

 

2.搭建好硬件平台如下所示，生成bit文件并导出到SDK中。

3.创建Appliaction Project，选择Helloworld就行。读写SD卡用到了xilffs库，所以需要在bsp中添加xilffs库，同时选中xilffs库做如下修改配置。

在配置上，主要参考了这位博主：https://blog.csdn.net/pro_he/article/details/79937426#zedboard四嵌入式应用程序开发实例三写入数据到sd卡txt文件中。

4.先测试官方提供例程，找到Xilinx Vivado安装目录下的xilffs提供代码，按照版本选择，我的是3.7，D:\Xilinx\SDK\2017.4\data\embeddedsw\lib\sw_services\xilffs_v3_7\examples，将example内容拷贝到helloworld.c中。

这里面主要就是实现了向SD卡中写数据，再读出写入的数据，最后做判断比较两者数据，比较简单。但代码提供的是生成了一个Test.bin文件，在Ubuntu下使用vim查看如下。

将其用：%！xxd转换后，可看出具体数据，写入是没有问题的。

5.如何将数据提取出来去使用呢？我用的是UltraEdit，打开如下

选中所有数据，右键 ——> 十六进制复制选定视图（V），粘贴到Test.c文件中，然后删除掉不需要的列就可以了。

 6.读写SD卡的代码如下：

/***************************** Include Files *********************************/

#include "xparameters.h"	/* SDK generated parameters */
#include "xsdps.h"		/* SD device driver */
#include "xil_printf.h"
#include "ff.h"
#include "xil_cache.h"
#include "xplatform_info.h"

/************************** Constant Definitions *****************************/


/**************************** Type Definitions *******************************/

/***************** Macros (Inline Functions) Definitions *********************/

/************************** Function Prototypes ******************************/
int FfsSdPolledExample(void);

/************************** Variable Definitions *****************************/
static FIL fil;		/* File object */
static FATFS fatfs;
/*
 * To test logical drive 0, FileName should be "0:/<File name>" or
 * "<file_name>". For logical drive 1, FileName should be "1:/<file_name>"
 */
static char FileName[32] = "Test.bin";
static char *SD_File;
u32 Platform;

#ifdef __ICCARM__
#pragma data_alignment = 32
u8 DestinationAddress[10*1024*1024];
u8 SourceAddress[10*1024*1024];
#pragma data_alignment = 4
#else
u8 DestinationAddress[10*1024*1024] __attribute__ ((aligned(32)));
u8 SourceAddress[10*1024*1024] __attribute__ ((aligned(32)));
#endif

#define TEST 7

/*****************************************************************************/
/**
*
* Main function to call the SD example.
*
* @param	None
*
* @return	XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note		None
*
******************************************************************************/
int main(void)
{
	int Status;

	xil_printf("SD Polled File System Example Test \r\n");

	Status = FfsSdPolledExample();
	if (Status != XST_SUCCESS) {
		xil_printf("SD Polled File System Example Test failed \r\n");
		return XST_FAILURE;
	}

	xil_printf("Successfully ran SD Polled File System Example Test \r\n");

	return XST_SUCCESS;

}

/*****************************************************************************/
/**
*
* File system example using SD driver to write to and read from an SD card
* in polled mode. This example creates a new file on an
* SD card (which is previously formatted with FATFS), write data to the file
* and reads the same data back to verify.
*
* @param	None
*
* @return	XST_SUCCESS if successful, otherwise XST_FAILURE.
*
* @note		None
*
******************************************************************************/
int FfsSdPolledExample(void)
{
	FRESULT Res;
	UINT NumBytesRead;
	UINT NumBytesWritten;
	u32 BuffCnt;
	u32 FileSize = (8*1024*1024);
	/*
	 * To test logical drive 0, Path should be "0:/"
	 * For logical drive 1, Path should be "1:/"
	 */
	TCHAR *Path = "0:/";

	Platform = XGetPlatform_Info();
	if (Platform == XPLAT_ZYNQ_ULTRA_MP) {
		/*
		 * Since 8MB in Emulation Platform taking long time, reduced
		 * file size to 8KB.
		 */
		FileSize = 8*1024;
	}

	for(BuffCnt = 0; BuffCnt < FileSize; BuffCnt++){
		SourceAddress[BuffCnt] = TEST + BuffCnt;
	}

	/*
	 * Register volume work area, initialize device
	 */
	Res = f_mount(&fatfs, Path, 0);

	if (Res != FR_OK) {
		return XST_FAILURE;
	}

	/*
	 * Path - Path to logical driver, 0 - FDISK format.
	 * 0 - Cluster size is automatically determined based on Vol size.
	 */
	Res = f_mkfs(Path, 0, 0);
	if (Res != FR_OK) {
		return XST_FAILURE;
	}

	/*
	 * Open file with required permissions.
	 * Here - Creating new file with read/write permissions. .
	 * To open file with write permissions, file system should not
	 * be in Read Only mode.
	 */
	SD_File = (char *)FileName;

	Res = f_open(&fil, SD_File, FA_CREATE_ALWAYS | FA_WRITE | FA_READ);
	if (Res) {
		return XST_FAILURE;
	}

	/*
	 * Pointer to beginning of file .
	 */
	Res = f_lseek(&fil, 0);
	if (Res) {
		return XST_FAILURE;
	}

	/*
	 * Write data to file.
	 */
	Res = f_write(&fil, (const void*)SourceAddress, FileSize,
			&NumBytesWritten);
	if (Res) {
		return XST_FAILURE;
	}

	/*
	 * Pointer to beginning of file .
	 */
	Res = f_lseek(&fil, 0);
	if (Res) {
		return XST_FAILURE;
	}

	/*
	 * Read data from file.
	 */
	Res = f_read(&fil, (void*)DestinationAddress, FileSize,
			&NumBytesRead);
	if (Res) {
		return XST_FAILURE;
	}

	/*
	 * Data verification
	 */
	for(BuffCnt = 0; BuffCnt < FileSize; BuffCnt++){
		if(SourceAddress[BuffCnt] != DestinationAddress[BuffCnt]){
			return XST_FAILURE;
		}
	}

	/*
	 * Close file.
	 */
	Res = f_close(&fil);
	if (Res) {
		return XST_FAILURE;
	}

	return XST_SUCCESS;
}

最后根据自己的需要进行修改就行，我用到的是修改了SourceAddress[ ]的大小以及内容取值。

u8 SourceAddress[10*1024*1024];

for(BuffCnt = 0; BuffCnt < FileSize; BuffCnt++){
		SourceAddress[BuffCnt] = TEST + BuffCnt;
	}