如何快速检测NAND的坏块

如何快速检测NAND的坏块

首先调用erase,将NAND全部擦除一遍,然后执行如下检测操作,
如果页大于512字节,
badblockpos   = 0;
badblockbytes = 2;
如果页小于512字节,
badblockpos   = 5;
badblockbytes = 1;
读取每个block的前两页OOB区域的第badblockpos开始的后badblockbytes字节是否为0xff,
如果是,那么说明该block是好的,否则该block是坏块[gliethttp_20080523]！

UINT_T create_bbt(FlashBootType_T fbt)
{
    UINT_T Retval;
    P_FlashProperties_T pFlashP = GetFlashProperties(fbt);
    UINT_T BlkSize,BlkNum;
    UINT_T flash_addr;
#define page_size (2048)
#define page_spare_size (64)
#define block_size (64*page_size)
#define tmp_buffer_addr (0x80200000 - page_size - page_spare_size)
#define tmp_spare_buffer_addr (tmp_buffer_addr + page_size)
    int i,j;
    char *bbpos;

    bbpos = (char*)(tmp_spare_buffer_addr + 0);
    BlkSize = pFlashP->BlockSize;
    BlkNum = pFlashP->NumBlocks;
    
    for(i = 0;i < BlkNum;i++)
    {
        flash_addr = i * BlkSize;
        for(j = 0;j < 2;j++)
        {
            Retval = xdfc_read((UINT_T *)tmp_buffer_addr, flash_addr + j*page_size, page_size, (UINT_T *)tmp_spare_buffer_addr, GetNANDProperties());
            if(Retval)
            {
                goto __create_bbt_mark;
            }
            
            if(bbpos[0] != 0xff)goto __create_bbt_mark;
            if(bbpos[1] != 0xff)goto __create_bbt_mark;
        }
        continue;

__create_bbt_mark:
        RelocateBlock( i, &GetFMProperties()->BBT, fbt );
    }
}