本帖最后由 Superusrss 于 2025-5-11 10:10 编辑
刚查了下发现类似的问题，不知道对不对，Cache同步是按行同步的，如果同步的内容的地址不是与Cache行的地址对齐，将会在无效化Cache操作时，丢失与同步内容地址相邻的但存放于Cache中的数据，出处： https://blog.csdn.net/Fairchild_1947/article/details/122268377
但是我不同意他贴出的代码，其中第一个& 0x3 是确保idma地址是4字节对齐，第二个& ~0x1F 确保地址是32byte对齐。我开启所有cache后fatfs还是报错FR_INT_ERR，确实是SCB操作把dcache内容改了，关闭cache后正常，头大。已开启ENABLE_SCRATCH_BUFFER 和 ENABLE_SD_DMA_CACHE_MAINTENANCE
[C] 纯文本查看 复制代码 DRESULT SD_read(BYTE lun, BYTE *buff, DWORD sector, UINT count)
{
DRESULT res = RES_ERROR;
uint32_t timeout;
#if defined(ENABLE_SCRATCH_BUFFER)
uint8_t ret;
#endif
#if (ENABLE_SD_DMA_CACHE_MAINTENANCE == 1)
uint32_t alignedAddr;
#endif
/*
* ensure the SDCard is ready for a new operation
*/
if (SD_CheckStatusWithTimeout(SD_TIMEOUT) < 0)
{
return res;
}
#if defined(ENABLE_SCRATCH_BUFFER)
if (!((uint32_t)buff & 0x3))
{
#endif
if(BSP_SD_ReadBlocks_DMA((uint32_t*)buff,
(uint32_t) (sector),
count) == MSD_OK)
{
ReadStatus = 0;
/* Wait that the reading process is completed or a timeout occurs */
timeout = HAL_GetTick();
while((ReadStatus == 0) && ((HAL_GetTick() - timeout) < SD_TIMEOUT))
{
}
/* in case of a timeout return error */
if (ReadStatus == 0)
{
res = RES_ERROR;
}
else
{
ReadStatus = 0;
timeout = HAL_GetTick();
while((HAL_GetTick() - timeout) < SD_TIMEOUT)
{
if (BSP_SD_GetCardState() == SD_TRANSFER_OK)
{
res = RES_OK;
#if (ENABLE_SD_DMA_CACHE_MAINTENANCE == 1)
/*
the SCB_InvalidateDCache_by_Addr() requires a 32-Byte aligned address,
adjust the address and the D-Cache size to invalidate accordingly.
*/
alignedAddr = (uint32_t)buff & ~0x1F;
SCB_InvalidateDCache_by_Addr((uint32_t*)alignedAddr, count*BLOCKSIZE + ((uint32_t)buff - alignedAddr));
#endif
break;
}
}
}
}
#if defined(ENABLE_SCRATCH_BUFFER)
}
else
{
/* Slow path, fetch each sector a part and memcpy to destination buffer */
int i;
for (i = 0; i < count; i++) {
ret = BSP_SD_ReadBlocks_DMA((uint32_t*)scratch, (uint32_t)sector++, 1);
if (ret == MSD_OK) {
/* wait until the read is successful or a timeout occurs */
timeout = HAL_GetTick();
while((ReadStatus == 0) && ((HAL_GetTick() - timeout) < SD_TIMEOUT))
{
}
if (ReadStatus == 0)
{
res = RES_ERROR;
break;
}
ReadStatus = 0;
#if (ENABLE_SD_DMA_CACHE_MAINTENANCE == 1)
/*
*
* invalidate the scratch buffer before the next read to get the actual data instead of the cached one
*/
SCB_InvalidateDCache_by_Addr((uint32_t*)scratch, BLOCKSIZE);
#endif
memcpy(buff, scratch, BLOCKSIZE);
buff += BLOCKSIZE;
}
else
{
break;
}
}
if ((i == count) && (ret == MSD_OK))
res = RES_OK;
}
#endif
return res;
} | 
发表于 2021-12-12 14:54:34
发表于 2021-12-13 00:38:21
楼主
