My current dockstar setup consists of:
1. mtd0: Jeff's uboot.
2. mtd1: Jeff's rescue system kernel.
3. mtd2: Jeff's rescue system rootfs on ubifs.
4. mtd3: emdebian install on ubifs.
I tried to do a backup of all the mtd partitions with nanddump. mtd1 to mtd3 proceeded without any errors. But mtd0 threw out a whole chain of ECC errors:
root@debian:~# nanddump -f mtd0.bin /dev/mtd0
ECC failed: 0
ECC corrected: 0
Number of bad blocks: 0
Number of bbt blocks: 0
Block size 131072, page size 2048, OOB size 64
Dumping data starting at 0x00000000 and ending at 0x00100000...
ECC: 8 uncorrectable bitflip(s) at offset 0x000a0000
ECC: 8 uncorrectable bitflip(s) at offset 0x000a0800
ECC: 8 uncorrectable bitflip(s) at offset 0x000a1000
ECC: 8 uncorrectable bitflip(s) at offset 0x000a1800
ECC: 8 uncorrectable bitflip(s) at offset 0x000a2000
ECC: 8 uncorrectable bitflip(s) at offset 0x000a2800
ECC: 8 uncorrectable bitflip(s) at offset 0x000a3000
ECC: 8 uncorrectable bitflip(s) at offset 0x000a3800
ECC: 8 uncorrectable bitflip(s) at offset 0x000a4000
....
I then ran nandtest
root@debian:~# nandtest /dev/mtd0
ECC corrections: 0
ECC failures : 960
Bad blocks : 0
BBT blocks : 0
000e0000: checking...
Finished pass 1 successfully
Should I be concerned with the ECC failures in mtd0? When the dockstar was first delivered to me, it was in a unbootable state "Verifying Checksum ... Bad Data CRC" and I did a rebuild with the serial connection.