【求助】这几天搞F407的FATFS的一个问题

承德外八庙

用的FATFS基本上是参考一个开发板附赠的程序，编译器是IAR 6.60.1，写一张2G的TF卡
跑到readblock这个函数这里

SD_Error SD_ReadBlock(uint8_t *readbuff, uint64_t ReadAddr, uint16_t BlockSize)

{

SD_Error errorstatus = SD_OK;

#if defined (SD_POLLING_MODE) 

uint32_t count = 0, *tempbuff = (uint32_t *)readbuff;

#endif

TransferError = SD_OK;

TransferEnd = 0;

StopCondition = 0;

SDIO->DCTRL = 0x0;

#if defined (SD_DMA_MODE)

SDIO_ITConfig(SDIO_IT_DCRCFAIL | SDIO_IT_DTIMEOUT | SDIO_IT_DATAEND | SDIO_IT_RXOVERR | SDIO_IT_STBITERR, ENABLE);

SDIO_DMACmd(ENABLE);

SD_LowLevel_DMA_RxConfig((uint32_t *)readbuff, BlockSize);

#endif

if (CardType == SDIO_HIGH_CAPACITY_SD_CARD)

{

BlockSize = 512;

ReadAddr /= 512;

}

/* Set Block Size for Card */

SDIO_CmdInitStructure.SDIO_Argument = (uint32_t)BlockSize;

SDIO_CmdInitStructure.SDIO_CmdIndex = SD_CMD_SET_BLOCKLEN;

SDIO_CmdInitStructure.SDIO_Response = SDIO_Response_Short;

SDIO_CmdInitStructure.SDIO_Wait = SDIO_Wait_No;

SDIO_CmdInitStructure.SDIO_CPSM = SDIO_CPSM_Enable;

SDIO_SendCommand(&SDIO_CmdInitStructure);

errorstatus = CmdResp1Error(SD_CMD_SET_BLOCKLEN);

if (SD_OK != errorstatus)

{

return(errorstatus);

}

到这里返回错误SD_BLOCK_LEN_ERR，跳出函数，下面的代码都没得跑
f_mount无问题，返回FR_OK
是不是TF卡自身的问题？还是其他方面？
//------------------------------------------------------
嗯，这个问题目前是解决了，是前面一个小细节的错误。
现在是这样的
在chk_mounted函数中有这样一段代码

fmt = check_fs(fs, bsect = 0); /* Check sector 0 if it is a VBR */

if (fmt == 1) { /* Not an FAT-VBR, the disk may be partitioned */

/* Check the partition listed in top of the partition table */

tbl = &fs->win[MBR_Table + LD2PT(vol) * 16]; /* Partition table */

if (tbl[4]) { /* Is the partition existing? */

bsect = LD_DWORD(&tbl[8]); /* Partition offset in LBA */

fmt = check_fs(fs, bsect); /* Check the partition */

}

}

if (fmt == 3) return FR_DISK_ERR;

if (fmt) return FR_NO_FILESYSTEM; /* No FAT volume is found */

无非就是检测FAT分区的分区表和主引导记录之类

调用check_fs函数读取MBR和DBR的时候

BYTE check_fs ( /* 0:The FAT BR, 1:Valid BR but not an FAT, 2:Not a BR, 3isk error */

FATFS *fs, /* File system object */

DWORD sect /* Sector# (lba) to check if it is an FAT boot record or not */

)

{

unsigned long int watch_pointer1;

      //  disk_read(fs->drv, fs->win, sect, 1);

        watch_pointer1=LD_WORD(&fs->win[BS_55AA]);

        if (disk_read(fs->drv, fs->win, sect, 1) != RES_OK)   /* Load boot record */

        { 

return 3;

        }

        watch_pointer1=LD_WORD(&fs->win[BS_55AA]);

if (LD_WORD(&fs->win[BS_55AA]) != 0xAA55) /* Check record signature (always placed at offset 510 even if the sector size is >512) */

return 2;

if ((LD_DWORD(&fs->win[BS_FilSysType]) & 0xFFFFFF) == 0x544146) /* Check "FAT" string */

return 0;

if ((LD_DWORD(&fs->win[BS_FilSysType32]) & 0xFFFFFF) == 0x544146)

return 0;

return 1;

}

首先，BS_55AA是510，但实际上我们读回来的0xAA55位置是在508和509
其次，BS_FileType和BS_FileType32处没有分区表的信息，全部为0
第三就是如果将BS_55AA改到可以读回AA55的位置（508），依然没法读取到DBR
不知道有没有人知道这是什么问题

正点原子

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