DM8168在Nand Flash烧写文件系统地址疑问。

我开发用的是DVRRDK4.1，做了ubifs烧写到nand flash的文件系统分区。按照文档《DM81xx_DVR_RDK_Install_Guide》给出的操作命令，是从flash地址0x009c0000开始烧写。但是从内核代码中看

static struct mtd_partition ti816x_nand_partitions_bs128[] = {
	/* All the partition sizes are listed in terms of NAND block size */
	{
		.name		= "U-Boot",
		.offset		= 0,	/* Offset = 0x0 */
		.size		= 18 * SZ_128K,
		.mask_flags	= MTD_WRITEABLE,	/* force read-only */
	},
	{
		.name		= "U-Boot Env",
		.offset		= MTDPART_OFS_APPEND,	/* Offset = 0x240000 */
		.size		= 2 * SZ_128K,
	},
	{
		.name		= "U-Boot Logo",
		.offset		= MTDPART_OFS_APPEND,	/* Offset = 0x280000 */
		.size		= 24 * SZ_128K,
	},
	{
		.name		= "Kernel",
		.offset		= MTDPART_OFS_APPEND,	/* Offset = 0x580000 */
		.size		= 34 * SZ_128K,
	},
	{
		.name		= "File System",
		.offset		= MTDPART_OFS_APPEND,	/* Offset = 0x6C0000 */
		.size		= 1601 * SZ_128K,
	},
	{
		.name		= "Reserved",
		.offset		= MTDPART_OFS_APPEND,	/* Offset = 0xCEE0000 */
		.size		= MTDPART_SIZ_FULL,
	},

};

文件系统的分区起始地址是0x6C0000，为何要从0x9c0000烧写呢？而且我试过，如果从0x6C0000开始擦除，会导致不能引导内核，uboot找不到kernel文件，请问这是什么原因呢？