读取SD卡时，为什么会死在这个函数中FRESULT f_getfree

一眼万年

FRESULT f_getfree (

const TCHAR *path, /* Pointer to the logical drive number (root dir) */

DWORD *nclst, /* Pointer to the variable to return number of free clusters */

FATFS **fatfs /* Pointer to pointer to corresponding file system object to return */

)

{

FRESULT res;

DWORD n, clst, sect, stat;

UINT i;

BYTE fat, *p;

/* Get drive number */

res = chk_mounted(&path, fatfs, 0);

if (res == FR_OK) {

/* If free_clust is valid, return it without full cluster scan */

if ((*fatfs)->free_clust <= (*fatfs)->n_fatent - 2) {

*nclst = (*fatfs)->free_clust;

} else {

/* Get number of free clusters */

fat = (*fatfs)->fs_type;

n = 0;

if (fat == FS_FAT12) {

clst = 2;

do {

stat = get_fat(*fatfs, clst);

if (stat == 0xFFFFFFFF) { res = FR_DISK_ERR; break; }

if (stat == 1) { res = FR_INT_ERR; break; }

if (stat == 0) n++;

} while (++clst < (*fatfs)->n_fatent);

} else {

clst = (*fatfs)->n_fatent;

sect = (*fatfs)->fatbase;

i = 0; p = 0;

do {

if (!i) {

res = move_window(*fatfs, sect++);

if (res != FR_OK) break;

p = (*fatfs)->win;

i = SS(*fatfs);

}

if (fat == FS_FAT16) {

if (LD_WORD(p) == 0) n++;

p += 2; i -= 2;

} else {

if ((LD_DWORD(p) & 0x0FFFFFFF) == 0) n++;

p += 4; i -= 4;

}

} while (--clst);

}

(*fatfs)->free_clust = n;

if (fat == FS_FAT32) (*fatfs)->fsi_flag = 1;

*nclst = n;

}

}

LEAVE_FF(*fatfs, res);

}

正点原子

回复【楼主位】一眼万年:
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这个函数不会有问题，检查底层接口。
diskio里面的函数。

一眼万年

回复【2楼】正点原子:
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好，谢谢原子哥，我再检查下~