TI中文支持网硬件平台：AM3352+ nandflash M29F2G08ABAEA
通过烧写程序出现如下问题
1.通过uboot加载程序，内核加载完成以后出现ubi文件系统挂载不起问题，打印如下
加载命令：
rootfs：
mw.b 0x82000000 0xFF 0x3000000;loadb 0x82000000
nand erase 0xA00000 0x3100000;nandecc sw;nand write 0x82000000 0xA00000 0x3000000
打印log：
[ 2.302067] UBI: attaching mtd9 to ubi0
[ 2.307178] UBI warning: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read only 64 bytes, retry
[ 2.319648] UBI warning: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read only 64 bytes, retry
[ 2.332081] UBI warning: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read only 64 bytes, retry
[ 2.344509] UBI error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read 64 bytes
2.通过uboot调试空的ubi文件系统，打印如下：
U-Boot# nand erase.part NAND.rootfsNAND erase.part: device 0 offset 0xa00000, size 0xf600000
Erasing at 0xffe0000 — 100% complete.
OK
U-Boot# ubi part NAND.rootfs
UBI: attaching mtd1 to ubi0
UBI: physical eraseblock size: 131072 bytes (128 KiB)
UBI: logical eraseblock size: 129024 bytes
UBI: smallest flash I/O unit: 2048
UBI: sub-page size: 512
UBI: VID header offset: 512 (aligned 512)
UBI: data offset: 2048
UBI: empty MTD device detected
UBI: create volume table (copy #1)
UBI: create volume table (copy #2)
UBI: attached mtd1 to ubi0
UBI: MTD device name: "mtd=9"
UBI: MTD device size: 246 MiB
UBI: number of good PEBs: 1968
UBI: number of bad PEBs: 0
UBI: max. allowed volumes: 128
UBI: wear-leveling threshold: 4096
UBI: number of internal volumes: 1
UBI: number of user volumes: 0
UBI: available PEBs: 1945
UBI: total number of reserved PEBs: 23
UBI: number of PEBs reserved for bad PEB handling: 19
UBI: max/mean erase counter: 1/0
U-Boot# ubi create NAND.file-system
No size specified -> Using max size (250951680)
Creating dynamic volume NAND.file-system of size 250951680
U-Boot# ubi write 0x82000000 NAND.rootfs 0x02420000
Volume NAND.rootfs not found!
U-Boot# ubi write 0x82000000 NAND.file-system 0x02420000
37879808 bytes written to volume NAND.file-system
U-Boot# ubi part
Device 0: nand0, partition NAND.rootfs
问题1：什么原因导致UBI error: ubi_io_read: error -74 (ECC error) while reading 64 bytes from PEB 0:0, read 64 bytes，怎么解决？
问题2：为什么空的ubi文件系统创建没有问题？
附 ubi文件系统制作命令：
mkfs.ubifs –F -q -r ./rootfs -m 2048 -e 129024 -c 2047 -o rootfs_05252200.img
ubinize -o rootfs_05252200.img -m 2048 -p 128KiB -s 512 ubinize.cfg
yongqing wang：
ECC校验问题，可能是你改了代码里有bug
yongqing wang：
回复 yongqing wang:
看一下是否修改了pmecc
jianzhong hu：
回复 yongqing wang:
这个是哪里修改的呢？
Shine：
看上去像是ECC的问题，请看一下nand ecc scheme用的是什么？SDK是哪个版本？
jianzhong hu：
回复 Shine:
SDK 我用的是am335x-evm-sdk-src-07.00.00.00.tar.gz，nandecc scheme 我用的是bch8，我在uboot源码里面增加了static int do_switch_ecc(cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])这个nandecc命令，程序写入nand的时候用了nandecc hw bch8
yongqing wang：
回复 jianzhong hu:
意思是你在要来代码的基础上加的东西有bug，影响到了ECC
