为什么linux启动根文件系统会出现以下报错？

ARM-linux-gcc  version 4.3.2
linux-3.4.2
根文件系统（用的是老师提供的）： fs_mini_mdev_new.yaffs2
分区信息   (512K, 128K, 4M, -)
0x000000000000-0x000000080000 : "boot"
0x000000080000-0x0000000a0000 : "param"
0x0000000a0000-0x0000004a0000 : "kernel"
0x0000004a0000-0x000010000000 : "root"



启动内核时报如下错误信息， 我感觉好像是没有找到yaffs2 文件系统。 但我已经在 make menuconfig 中 把yaffs2 文件系统支持添加了。而且内核也打了yaffas2的补丁。请老师帮忙看看。谢谢！

uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 2
EXT3-fs (mtdblock3): error: unable to read superblock
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 2
EXT2-fs (mtdblock3): error: unable to read superblock
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 0
Buffer I/O error on device mtdblock3, logical block 0
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 0
Buffer I/O error on device mtdblock3, logical block 0
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 8
Buffer I/O error on device mtdblock3, logical block 1
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 8
Buffer I/O error on device mtdblock3, logical block 1
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 16
Buffer I/O error on device mtdblock3, logical block 2
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 16
Buffer I/O error on device mtdblock3, logical block 2
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 24
Buffer I/O error on device mtdblock3, logical block 3
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 24
Buffer I/O error on device mtdblock3, logical block 3
uncorrectable error :
uncorrectable error :
end_request: I/O error, dev mtdblock3, sector 0
FAT-fs (mtdblock3): unable to read boot sector
VFS: Cannot open root device "mtdblock3" or unknown-block(31,3): error -5
Please append a correct "root=" boot option; here are the available partitions:
1f00             512 mtdblock0  (driver?)
1f01             128 mtdblock1  (driver?)
1f02            4096 mtdblock2  (driver?)
1f03          257408 mtdblock3  (driver?)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(31,3)
Backtrace:
[] (dump_backtrace+0x0/0x10c) from [] (dump_stack+0x18/0x1c)
r6:c38a7000 r5:fffffffb r4:c381df2c
[] (dump_stack+0x0/0x1c) from [] (panic+0x7c/0x1d0)
[] (panic+0x0/0x1d0) from [] (mount_block_root+0x180/0x23c)
r3:00000000 r2:c384c9f4 r1:c381df2c r0:c03c5b60
[] (mount_block_root+0x0/0x23c) from [] (mount_root+0x88/0x108)
[] (mount_root+0x0/0x108) from [] (prepare_namespace+0x110/0x1d0)
r7:c04774e0 r6:c044573c r5:c044573c r4:c0477540
[] (prepare_namespace+0x0/0x1d0) from [] (kernel_init+0x164/0x1b8)
r6:00000008 r5:c0444f10 r4:c0449c34
[] (kernel_init+0x0/0x1b8) from [] (do_exit+0x0/0x76c)