[U-Boot-Users] Loading from NAND using 'nboot' Periodically Fails Where 'nand read' Succeeds

[Grant Erickson <gerickson@nuovations.com>]

On 6/2/08 3:02 PM, Grant Erickson wrote:
> On 6/2/08 11:21 AM, Scott Wood wrote:
>> On Mon, Jun 02, 2008 at 08:22:21AM +0200, Stefan Roese wrote:
>>> Hi Grant,
>>> 
>>> On Monday 02 June 2008, Grant Erickson wrote:
>>>> Before I jump in with the BDI and start debugging, has anyone else using
>>>> 'nboot' and FIT images noticed that 'nboot' periodically fails where 'nand
>>>> read.i' of the SAME region of NAND succeeds?
>>> 
>>> Not sure here, since I never used nboot before. But "nand read.i" skips bad
>>> blocks and perhaps "nboot" not? I suggest that you check if this is the case
>>> and if you have bad blocks in this NAND area.
>> 
>> It is indeed the case -- you need to use "nboot.i".
>> 
>> -Scott
> 
> Scott and Stefan,
> 
> Thanks for the suggestion. That solved it. As an academic exercise, is there
> any practical reason a system would want to use nboot, as I erroneously chose
> to do, without .i|.jffs2|.e?

It would appear I was slightly too quick to regard this as fixed. What I
found this morning is the following with the AMCC "Haleakala" board:

1) A 48+ hour reboot test bouncing between the boot0 and boot1 partitions
passed, where boot0 and boot1 are defined as:

    => printenv bootaddr bootcmd boot0 boot1
    bootaddr=800000
    bootcmd=run boot0 || run boot1 || reset
    boot0=nboot.i ${bootaddr} 0 0 && setenv bootargs root=/dev/mtdblock9 &&
run addjffs2 addtty && bootm ${bootaddr}
    boot1=nboot.i ${bootaddr} 0 1C00000 && setenv bootargs
root=/dev/mtdblock11 && run addjffs2 addtty && bootm ${bootaddr}

2) I stopped that test and added power-cycling to the mix and it, again,
immediately failed with:

    Loading from NAND 64MiB 3,3V 8-bit, offset 0x0
    ** Bad FIT image format

    Loading from NAND 64MiB 3,3V 8-bit, offset 0x1c00000
    ** Bad FIT image format

So, resets are not enough to trigger this issue, it takes a power cycle.

I have found that this state is recoverable by issuing a 'nand read.i' and
then re-running 'boot0':

    => nand read.i ${bootaddr} 0 400000 && run boot0

From that point forward, both boot0 and boot1 work flawlessly.

I have also found that NFS booting to get Linux up and running, restarting
and then running boot0 or boot1 also works from that point forward until the
next power cycle.

So, there seems to be some specific state the PowerPC NDFC (NAND controller)
or Samsung K9F1208U0B NAND gets in where either 'nand read.i' or the Linux
MTD driver kick one or both in such a way as to get out of whatever state
prevents nboot.i from working.

Strangely though, both nand read.i and nboot.i both exercise the same
nand_read_opts path in nand_util.c.

Any thoughts?

Regards,

Grant