关于FL2440启动参数的疑问

为什么根文件系统是在第6个分区，而启动参数中 root会设置为/dev/mtdblock3 呢？实在是不明白，还请官方给与解答。

NAND ID is 0xecda

Please select which region to write : Esc to abort
0 : offset 0x00000000, size 0x00020000 [boot]
1 : offset 0x00020000, size 0x00060000 [bootParam]
2 : offset 0x00080000, size 0x00100000 [pic]
3 : offset 0x00180000, size 0x00380000 [MyApp]
4 : offset 0x00500000, size 0x00300000 [kernel]
5 : offset 0x00800000, size 0x03c00000 [fs_yaffs]
6 : offset 0x04400000, size 0x00080000 [eboot]
7 : offset 0x04480000, size 0x03b80000 [wince]


Set boot params = root=/dev/mtdblock3 init=/linuxrc load_ramdisk=0 console=ttySAC0,115200 mem=65536K devfs=mount display=lcd480 //bootloader 打印的信息
Load Kernel...
Uncompressing Linux................................................................................................................................ done, booting the kernel.