我现在试图为项目实施FatFs模块好几天了。
我的低级I / O配置正确实现，因为我可以使用示波器查看信号。但我似乎无法在SD-Card上进行正确的写作。我得到的是我SD-Card上的一个空文件，它可以正确创建。读取文件也可以正常工作。当我使用MPLAB X进行调试时，我发现f_write函数从未离开for循环。
这是我的main.c代码：
/*
Main application
*/
FATFS FatFs;
FIL fil1, fil2;
void main(void)
{
SYSTEM_Init();
BYTE buffer[4];
UINT bw, br;
FRESULT fr;
if(f_mount(&FatFs, "", 1) == FR_OK)
{
//open source file
fr = f_open(&fil1, "READ.TXT", FA_READ);
if(fr) return;
//create destination file
fr = f_open(&fil2, "WRITE.TXT", FA_WRITE | FA_CREATE_ALWAYS);
if(fr) return;
//copy 1 to 2
for(;;){
fr = f_read(&fil1, buffer, sizeof buffer, &br);
if(fr || br == 0) break;
fr = f_write(&fil2, buffer, br, &bw);
if(fr || bw < br) break;
}
// const char *writedata = &write;
// //f_printf(&fil, "%d", 1234);
// f_write(&fil, writedata, strlen(writedata), &bw);
f_close(&fil1);
f_close(&fil2);
f_mount(NULL, "", 0);
}
return;
}
这是我的diskio.c代码：
/*-----------------------------------------------------------------------*/
/* Low level disk I/O module skeleton for FatFs (C)ChaN, 2016 */
/*-----------------------------------------------------------------------*/
/* If a working storage control module is available, it should be */
/* attached to the FatFs via a glue function rather than modifying it. */
/* This is an example of glue functions to attach various exsisting */
/* storage control modules to the FatFs module with a defined API. */
/*-----------------------------------------------------------------------*/
#ifdef __XC8
#include <p18f46j50.h>
#endif
#ifndef __XC8
#include <p18cxxx.h>
#endif
#include "diskio.h" /* FatFs lower layer API */
#include "sdspi.h"
#include "sdctrl.h"
/* Definitions of physical drive number for each drive */
#define DEV_RAM 0 /* Example: Map Ramdisk to physical drive 0 */
#define DEV_MMC 1 /* Example: Map MMC/SD card to physical drive 1 */
#define DEV_USB 2 /* Example: Map USB MSD to physical drive 2 */
#define _XTAL_FREQ 8000000
/*--------------------------------------------------------------------------
Module Private Functions
---------------------------------------------------------------------------*/
/* Definitions for SDC command */
#define CMD0 (0) /* GO_IDLE_STATE */
#define CMD1 (1) /* SEND_OP_COND (MMC) */
#define ACMD41 (0x80+41) /* SEND_OP_COND (SDC) */
#define CMD8 (8) /* SEND_IF_COND */
#define CMD9 (9) /* SEND_CSD */
#define CMD10 (10) /* SEND_CID */
#define CMD12 (12) /* STOP_TRANSMISSION */
#define ACMD13 (0x80+13) /* SD_STATUS (SDC) */
#define CMD16 (16) /* SET_BLOCKLEN */
#define CMD17 (17) /* READ_SINGLE_BLOCK */
#define CMD18 (18) /* READ_MULTIPLE_BLOCK */
#define CMD23 (23) /* SET_BLOCK_COUNT (MMC) */
#define ACMD23 (0x80+23) /* SET_WR_BLK_ERASE_COUNT (SDC) */
#define CMD24 (24) /* WRITE_BLOCK */
#define CMD25 (25) /* WRITE_MULTIPLE_BLOCK */
#define CMD32 (32) /* ERASE_ER_BLK_START */
#define CMD33 (33) /* ERASE_ER_BLK_END */
#define CMD38 (38) /* ERASE */
#define CMD55 (55) /* APP_CMD */
#define CMD58 (58) /* READ_OCR */
/* MMC card type flags (MMC_GET_TYPE) */
#define CT_MMC 0x01 /* MMC ver 3 */
#define CT_SD1 0x02 /* SD ver 1 */
#define CT_SD2 0x04 /* SD ver 2 */
#define CT_SDC (CT_SD1|CT_SD2) /* SD */
#define CT_BLOCK 0x08 /* Block addressing */
static
DSTATUS Stat = STA_NOINIT; /* Disk status */
static
BYTE CardType; /* Card type flags */
/*-----------------------------------------------------------------------*/
/* Wait for card ready */
/*-----------------------------------------------------------------------*/
static
BYTE wait_ready (void) /* 1:Ready, 0:Timeout */
{
UINT tmr;
for (tmr = 5000; tmr; tmr--) { /* Wait for ready in timeout of 500ms */
if (sdspi_rxByte() == 0xFF) break;
__delay_us(100);
}
return tmr ? 1 : 0;
}
/*-----------------------------------------------------------------------*/
/* Deselect the card and release SPI bus */
/*-----------------------------------------------------------------------*/
static
void deselect (void)
{
sd_deselect(); /* Set CS# high */
sdspi_rxByte(); /* Dummy clock (force DO hi-z for multiple slave SPI) */
}
/*-----------------------------------------------------------------------*/
/* Select the card and wait for ready */
/*-----------------------------------------------------------------------*/
static
BYTE select (void) /* 1:Successful, 0:Timeout */
{
sd_select(); /* Set CS# low */
sdspi_rxByte(); /* Dummy clock (force DO enabled) */
if (wait_ready()) return 1; /* Wait for card ready */
deselect();
return 0; /* Timeout */
}
/*-----------------------------------------------------------------------*/
/* Receive a data packet from MMC */
/*-----------------------------------------------------------------------*/
static
BYTE rcvr_datablock (
BYTE *buff, /* Data buffer to store received data */
UINT btr /* Byte count (must be multiple of 4) */
)
{
BYTE token;
UINT tmr;
for (tmr = 2000; tmr; tmr--) { /* Wait for data packet in timeout of 200ms */
token = sdspi_rxByte();
if (token != 0xFF) break;
// __delay_us(100);
}
if (token != 0xFE) return 0; /* If not valid data token, retutn with error */
do
*buff++ = sdspi_rxByte(); /* Receive the data block into buffer */
while (--btr);
sdspi_rxByte(); /* Discard CRC */
sdspi_rxByte();
return 1; /* Return with success */
}
/*-----------------------------------------------------------------------*/
/* Send a data packet to MMC */
/*-----------------------------------------------------------------------*/
#if _USE_WRITE
static
BYTE xmit_datablock (
const BYTE *buff, /* 512 byte data block to be transmitted */
BYTE token /* Data/Stop token */
)
{
BYTE resp;
WORD i;
if (!wait_ready()) return 0;
sdspi_txByte(token); /* Xmit data token */
if (token != 0xFD) { /* Is data token */
i = 512;
do
{
sdspi_txByte(*buff++); /* Xmit the data block to the MMC */
__delay_us(100);
}while (--i);
sdspi_rxByte(); /* CRC (Dummy) */
sdspi_rxByte();
resp = sdspi_rxByte(); /* Reveive data response */
if ((resp & 0x1F) != 0x05) /* If not accepted, return with error */
return 0;
}
return 1;
}
#endif
/*-----------------------------------------------------------------------*/
/* Send a command packet to MMC */
/*-----------------------------------------------------------------------*/
/* NOTE: XC8 compiler is unable to allow recursion,
/ so the send_cmd function had to be divided */
#ifdef __XC8
static
BYTE __send_cmd ( /* Returns R1 resp (bit7==1:Send failed) */
BYTE cmd, /* Command index */
DWORD arg /* Argument */
)
{
BYTE n, res;
/* Select the card and wait for ready except to stop multiple block read */
if (cmd != CMD12) {
sd_deselect();
if (!select()) return 0xFF;
// sd_select();
// if (wait_ready() != 0xFF) return 0xFF;
}
/* Send command packet */
sdspi_txByte(0x40 | cmd); /* Start + Command index */
sdspi_txByte((BYTE)(arg >> 24)); /* Argument[31..24] */
sdspi_txByte((BYTE)(arg >> 16)); /* Argument[23..16] */
sdspi_txByte((BYTE)(arg >> 8)); /* Argument[15..8] */
sdspi_txByte((BYTE)arg); /* Argument[7..0] */
n = 0x01; /* Dummy CRC + Stop */
if (cmd == CMD0) n = 0x95; /* Valid CRC for CMD0(0) + Stop */
if (cmd == CMD8) n = 0x87; /* Valid CRC for CMD8(0x1AA) Stop */
sdspi_txByte(n);
/* Receive command response */
if (cmd == CMD12) sdspi_rxByte(); /* Skip a stuff byte when stop reading */
n = 10; /* Wait for a valid response in timeout of 10 attempts */
do
res = sdspi_rxByte();
while ((res & 0x80) && --n);
return res; /* Return with the response value */
}
#endif
static
BYTE send_cmd ( /* Returns R1 resp (bit7==1:Send failed) */
BYTE cmd, /* Command index */
DWORD arg /* Argument */
)
{
#ifndef __XC8
BYTE n;
#endif
BYTE res;
if (cmd & 0x80) { /* ACMD<n> is the command sequense of CMD55-CMD<n> */
cmd &= 0x7F;
#ifdef __XC8
res = __send_cmd(CMD55, 0);
#else
res = send_cmd(CMD55, 0);
#endif
if (res > 1) return res;
}
#ifdef __XC8
return __send_cmd(cmd, arg); /* Return with the response value */
#else
/* Select the card and wait for ready except to stop multiple block read */
if (cmd != CMD12) {
sd_deselect();
if (!select()) return 0xFF;
}
/* Send command packet */
sdspi_txByte(0x40 | cmd); /* Start + Command index */
sdspi_txByte((BYTE)(arg >> 24)); /* Argument[31..24] */
sdspi_txByte((BYTE)(arg >> 16)); /* Argument[23..16] */
sdspi_txByte((BYTE)(arg >> 8)); /* Argument[15..8] */
sdspi_txByte((BYTE)arg); /* Argument[7..0] */
n = 0x01; /* Dummy CRC + Stop */
if (cmd == CMD0) n = 0x95; /* Valid CRC for CMD0(0) + Stop */
if (cmd == CMD8) n = 0x87; /* Valid CRC for CMD8(0x1AA) Stop */
sdspi_txByte(n);
/* Receive command response */
if (cmd == CMD12) sdspi_rxByte(); /* Skip a stuff byte when stop reading */
n = 10; /* Wait for a valid response in timeout of 10 attempts */
do
res = sdspi_rxByte();
while ((res & 0x80) && --n);
return res; /* Return with the response value */
#endif
}
/*--------------------------------------------------------------------------
Public Functions
---------------------------------------------------------------------------*/
/*-----------------------------------------------------------------------*/
/* Initialize Disk Drive */
/*-----------------------------------------------------------------------*/
DSTATUS disk_initialize (
BYTE pdrv /* Physical drive nmuber (0) */
)
{
BYTE n, cmd, ty, ocr[4];
UINT tmr;
if (pdrv) return STA_NOINIT; /* Supports only single drive */
if (Stat & STA_NODISK) return Stat; /* No card in the socket */
sdspi_enable(); /* Enable the SPI port */
sdspi_setSlowMode(); /* Setup for slow mode */
for (n = 10; n; n--) sdspi_rxByte(); /* 80 dummy clocks */
ty = 0;
if (send_cmd(CMD0, 0) == 1) { /* Enter Idle state */
if (send_cmd(CMD8, 0x1AA) == 1) { /* SDv2? */
for (n = 0; n < 4; n++) ocr[n] = sdspi_rxByte(); /* Get trailing return value of R7 resp */
if (ocr[2] == 0x01 && ocr[3] == 0xAA) { /* The card can work at vdd range of 2.7-3.6V */
for (tmr = 1000; tmr; tmr--) { /* Wait for leaving idle state (ACMD41 with HCS bit) */
if (send_cmd(ACMD41, 1UL << 30) == 0) break;
__delay_ms(1);
}
if (tmr && send_cmd(CMD58, 0) == 0) { /* Check CCS bit in the OCR */
for (n = 0; n < 4; n++) ocr[n] = sdspi_rxByte();
ty = (ocr[0] & 0x40) ? CT_SD2 | CT_BLOCK : CT_SD2; /* SDv2 */
}
}
} else { /* SDv1 or MMCv3 */
if (send_cmd(ACMD41, 0) <= 1) {
ty = CT_SD1; cmd = ACMD41; /* SDv1 */
} else {
ty = CT_MMC; cmd = CMD1; /* MMCv3 */
}
for (tmr = 1000; tmr; tmr--) { /* Wait for leaving idle state */
if (send_cmd(cmd, 0) == 0) break;
__delay_ms(1);
}
if (!tmr || send_cmd(CMD16, 512) != 0) /* Set R/W block length to 512 */
ty = 0;
}
}
CardType = ty;
deselect();
if (ty) { /* Initialization succeded */
Stat &= ~STA_NOINIT; /* Clear STA_NOINIT */
sdspi_setFastMode();
}
return Stat;
}
/*-----------------------------------------------------------------------*/
/* Get Disk Status */
/*-----------------------------------------------------------------------*/
DSTATUS disk_status (
BYTE pdrv /* Physical drive nmuber (0) */
)
{
if (pdrv) return STA_NOINIT; /* Supports only single drive */
return Stat;
}
/*-----------------------------------------------------------------------*/
/* Read Sector(s) */
/*-----------------------------------------------------------------------*/
DRESULT disk_read (
BYTE pdrv, /* Physical drive nmuber (0) */
BYTE *buff, /* Pointer to the data buffer to store read data */
DWORD sector, /* Start sector number (LBA) */
UINT count /* Sector count (1..128) */
)
{
BYTE cmd;
if (pdrv || !count) return RES_PARERR;
if (Stat & STA_NOINIT) return RES_NOTRDY;
if (!(CardType & CT_BLOCK)) sector *= 512; /* Convert to byte address if needed */
cmd = count > 1 ? CMD18 : CMD17; /* READ_MULTIPLE_BLOCK : READ_SINGLE_BLOCK */
if (send_cmd(cmd, sector) == 0) {
do {
if (!rcvr_datablock(buff, 512)) break;
buff += 512;
} while (--count);
if (cmd == CMD18) send_cmd(CMD12, 0); /* STOP_TRANSMISSION */
}
deselect();
return count ? RES_ERROR : RES_OK;
}
/*-----------------------------------------------------------------------*/
/* Write Sector(s) */
/*-----------------------------------------------------------------------*/
#if _USE_WRITE
DRESULT disk_write (
BYTE pdrv, /* Physical drive nmuber (0) */
const BYTE *buff, /* Pointer to the data to be written */
DWORD sector, /* Start sector number (LBA) */
UINT count /* Sector count (1..128) */
)
{
if (pdrv || !count) return RES_PARERR;
if (Stat & STA_NOINIT) return RES_NOTRDY;
if (Stat & STA_PROTECT) return RES_WRPRT;
if (!(CardType & CT_BLOCK)) sector *= 512; /* Convert to byte address if needed */
if (count == 1) { /* Single block write */
if ((send_cmd(CMD24, sector) == 0) /* WRITE_BLOCK */
&& xmit_datablock(buff, 0xFE))
count = 0;
}
else { /* Multiple block write */
if (CardType & CT_SDC) send_cmd(ACMD23, count);
if (send_cmd(CMD25, sector) == 0) { /* WRITE_MULTIPLE_BLOCK */
do {
if (!xmit_datablock(buff, 0xFC)) break;
buff += 512;
} while (--count);
if (!xmit_datablock(0, 0xFD)) /* STOP_TRAN token */
count = 1;
}
}
deselect();
return count ? RES_ERROR : RES_OK;
}
#endif
/*-----------------------------------------------------------------------*/
/* Miscellaneous Functions */
/*-----------------------------------------------------------------------*/
//#if _USE_IOCTL
DRESULT disk_ioctl (
BYTE pdrv, /* Physical drive nmuber (0) */
BYTE cmd, /* Control code */
void *buff /* Buffer to send/receive control data */
)
{
DRESULT res;
BYTE n, csd[16], *ptr = buff;
DWORD csize;
if (pdrv) return RES_PARERR;
res = RES_ERROR;
if (Stat & STA_NOINIT) return RES_NOTRDY;
switch (cmd) {
case CTRL_SYNC : /* Make sure that no pending write process. Do not remove this or written sector might not left updated. */
if (select()) res = RES_OK;
break;
case GET_SECTOR_COUNT : /* Get number of sectors on the disk (DWORD) */
if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) {
if ((csd[0] >> 6) == 1) { /* SDC ver 2.00 */
csize = csd[9] + ((WORD)csd[8] << 8) + ((DWORD)(csd[7] & 63) << 16) + 1;
*(DWORD*)buff = csize << 10;
} else { /* SDC ver 1.XX or MMC*/
n = (csd[5] & 15) + ((csd[10] & 128) >> 7) + ((csd[9] & 3) << 1) + 2;
csize = (csd[8] >> 6) + ((WORD)csd[7] << 2) + ((WORD)(csd[6] & 3) << 10) + 1;
*(DWORD*)buff = csize << (n - 9);
}
res = RES_OK;
}
break;
case GET_BLOCK_SIZE : /* Get erase block size in unit of sector (DWORD) */
if (CardType & CT_SD2) { /* SDv2? */
if (send_cmd(ACMD13, 0) == 0) { /* Read SD status */
sdspi_rxByte();
if (rcvr_datablock(csd, 16)) { /* Read partial block */
for (n = 64 - 16; n; n--) sdspi_rxByte(); /* Purge trailing data */
*(DWORD*)buff = 16UL << (csd[10] >> 4);
res = RES_OK;
}
}
} else { /* SDv1 or MMCv3 */
if ((send_cmd(CMD9, 0) == 0) && rcvr_datablock(csd, 16)) { /* Read CSD */
if (CardType & CT_SD1) { /* SDv1 */
*(DWORD*)buff = (((csd[10] & 63) << 1) + ((WORD)(csd[11] & 128) >> 7) + 1) << ((csd[13] >> 6) - 1);
} else { /* MMCv3 */
*(DWORD*)buff = ((WORD)((csd[10] & 124) >> 2) + 1) * (((csd[11] & 3) << 3) + ((csd[11] & 224) >> 5) + 1);
}
res = RES_OK;
}
}
break;
/* Following commands are never used by FatFs module */
case MMC_GET_TYPE : /* Get card type flags (1 byte) */
*ptr = CardType;
res = RES_OK;
break;
case MMC_GET_CSD : /* Receive CSD as a data block (16 bytes) */
if (send_cmd(CMD9, 0) == 0 /* READ_CSD */
&& rcvr_datablock(ptr, 16))
res = RES_OK;
break;
case MMC_GET_CID : /* Receive CID as a data block (16 bytes) */
if (send_cmd(CMD10, 0) == 0 /* READ_CID */
&& rcvr_datablock(ptr, 16))
res = RES_OK;
break;
case MMC_GET_OCR : /* Receive OCR as an R3 resp (4 bytes) */
if (send_cmd(CMD58, 0) == 0) { /* READ_OCR */
for (n = 4; n; n--) *ptr++ = sdspi_rxByte();
res = RES_OK;
}
break;
case MMC_GET_SDSTAT : /* Receive SD statsu as a data block (64 bytes) */
if (send_cmd(ACMD13, 0) == 0) { /* SD_STATUS */
sdspi_rxByte();
if (rcvr_datablock(ptr, 64))
res = RES_OK;
}
break;
default:
res = RES_PARERR;
}
deselect();
return res;
}
//#endif
以下是f_write()
ff.c函数
FRESULT f_write (
FIL* fp, /* Pointer to the file object */
const void* buff, /* Pointer to the data to be written */
UINT btw, /* Number of bytes to write */
UINT* bw /* Pointer to number of bytes written */
)
{
FRESULT res;
FATFS *fs;
DWORD clst, sect;
UINT wcnt, cc, csect;
const BYTE *wbuff = (const BYTE*)buff;
*bw = 0; /* Clear write byte counter */
res = validate(&fp->obj, &fs); /* Check validity of the file object */
if (res != FR_OK || (res = (FRESULT)fp->err) != FR_OK) LEAVE_FF(fs, res); /* Check validity */
if (!(fp->flag & FA_WRITE)) LEAVE_FF(fs, FR_DENIED); /* Check access mode */
/* Check fptr wrap-around (file size cannot reach 4GiB on FATxx) */
if ((!_FS_EXFAT || fs->fs_type != FS_EXFAT) && (DWORD)(fp->fptr + btw) < (DWORD)fp->fptr) {
btw = (UINT)(0xFFFFFFFF - (DWORD)fp->fptr);
}
// HERE DOES THE LOOP HAPPEN
for ( ; btw; /* Repeat until all data written */
wbuff += wcnt, fp->fptr += wcnt, fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize, *bw += wcnt, btw -= wcnt) {
if (fp->fptr % SS(fs) == 0) { /* On the sector boundary? */
csect = (UINT)(fp->fptr / SS(fs)) & (fs->csize - 1); /* Sector offset in the cluster */
if (csect == 0) { /* On the cluster boundary? */
if (fp->fptr == 0) { /* On the top of the file? */
clst = fp->obj.sclust; /* Follow from the origin */
if (clst == 0) { /* If no cluster is allocated, */
clst = create_chain(&fp->obj, 0); /* create a new cluster chain */
}
} else { /* On the middle or end of the file */
#if _USE_FASTSEEK
if (fp->cltbl) {
clst = clmt_clust(fp, fp->fptr); /* Get cluster# from the CLMT */
} else
#endif
{
clst = create_chain(&fp->obj, fp->clust); /* Follow or stretch cluster chain on the FAT */
}
}
if (clst == 0) break; /* Could not allocate a new cluster (disk full) */
if (clst == 1) ABORT(fs, FR_INT_ERR);
if (clst == 0xFFFFFFFF) ABORT(fs, FR_DISK_ERR);
fp->clust = clst; /* Update current cluster */
if (fp->obj.sclust == 0) fp->obj.sclust = clst; /* Set start cluster if the first write */
}
#if _FS_TINY
if (fs->winsect == fp->sect && sync_window(fs) != FR_OK) ABORT(fs, FR_DISK_ERR); /* Write-back sector cache */
#else
if (fp->flag & FA_DIRTY) { /* Write-back sector cache */
if (disk_write(fs->drv, fp->buf, fp->sect, 1) != RES_OK) ABORT(fs, FR_DISK_ERR);
fp->flag &= (BYTE)~FA_DIRTY;
}
#endif
sect = clust2sect(fs, fp->clust); /* Get current sector */
if (!sect) ABORT(fs, FR_INT_ERR);
sect += csect;
cc = btw / SS(fs); /* When remaining bytes >= sector size, */
if (cc) { /* Write maximum contiguous sectors directly */
if (csect + cc > fs->csize) { /* Clip at cluster boundary */
cc = fs->csize - csect;
}
if (disk_write(fs->drv, wbuff, sect, cc) != RES_OK) ABORT(fs, FR_DISK_ERR);
#if _FS_MINIMIZE <= 2
#if _FS_TINY
if (fs->winsect - sect < cc) { /* Refill sector cache if it gets invalidated by the direct write */
mem_cpy(fs->win, wbuff + ((fs->winsect - sect) * SS(fs)), SS(fs));
fs->wflag = 0;
}
#else
if (fp->sect - sect < cc) { /* Refill sector cache if it gets invalidated by the direct write */
mem_cpy(fp->buf, wbuff + ((fp->sect - sect) * SS(fs)), SS(fs));
fp->flag &= (BYTE)~FA_DIRTY;
}
#endif
#endif
wcnt = SS(fs) * cc; /* Number of bytes transferred */
continue;
}
#if _FS_TINY
if (fp->fptr >= fp->obj.objsize) { /* Avoid silly cache filling on the growing edge */
if (sync_window(fs) != FR_OK) ABORT(fs, FR_DISK_ERR);
fs->winsect = sect;
}
#else
if (fp->sect != sect && /* Fill sector cache with file data */
fp->fptr < fp->obj.objsize &&
disk_read(fs->drv, fp->buf, sect, 1) != RES_OK) {
ABORT(fs, FR_DISK_ERR);
}
#endif
fp->sect = sect;
}
wcnt = SS(fs) - (UINT)fp->fptr % SS(fs); /* Number of bytes left in the sector */
if (wcnt > btw) wcnt = btw; /* Clip it by btw if needed */
#if _FS_TINY
if (move_window(fs, fp->sect) != FR_OK) ABORT(fs, FR_DISK_ERR); /* Move sector window */
mem_cpy(fs->win + fp->fptr % SS(fs), wbuff, wcnt); /* Fit data to the sector */
fs->wflag = 1;
#else
mem_cpy(fp->buf + fp->fptr % SS(fs), wbuff, wcnt); /* Fit data to the sector */
fp->flag |= FA_DIRTY;
#endif
}
fp->flag |= FA_MODIFIED; /* Set file change flag */
LEAVE_FF(fs, FR_OK);
}
答案 0 :(得分：2)
信不信由你，我有同样的问题，并且在数小时内搞砸了......这与XC8编译器如何解释for循环迭代器表达式有关。看起来它将执行的表达式数量有一个硬限制。如果编译器至少发出警告......修复它，添加
会很好 fp->fptr += wcnt;
fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize;
*bw += wcnt;
btw -= wcnt;
到for循环的底部，并将for循环更改为
for ( ; btw; wbuff += wcnt){//, fp->fptr += wcnt, fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize, *bw += wcnt, btw -= wcnt) {
答案 1 :(得分：0)
（edit）此问题将在FF13中纠正（/ edit）
这里有同样的问题。 FF12c，XC8编译器（v1.43）确实似乎与重新初始化参数有关。如果更改顺序并移动条件运算符？ ：有效到最后。
// wbuff += wcnt, fp->fptr += wcnt, fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize, *bw += wcnt, btw -= wcnt)
wbuff += wcnt, fp->fptr += wcnt, *bw += wcnt, btw -= wcnt, fp->obj.objsize = (fp->fptr > fp->obj.objsize) ? fp->fptr : fp->obj.objsize)
如果第一次写访问是针对完整扇区的，那么上面显示的上述解决方案对我不起作用。由于 continue 指令，程序不会在循环的底部执行添加的代码！
-vloki-