Nand read failed

Can you share the log? Commands you are using for flashing images? u-boot version?

Thanks,

Vaibhav

Hi,

Thank you vaibhav.

Please find the attached error log.

Nand commands what I used :

/* MLO */
nand erase 	
mmc init
fatload mmc 0 0x82000000 MLO
nand erase 0x0 0x50000
nandecc hw 2
nand write 0x82000000 0x0 0x50000
nand read 0x82000000 0x0 0x50000
/* U-boot */
fatload mmc 0 0x82000000 u-boot.bin
nand erase 0x80000 0x1C0000
nandecc sw
nand write 0x82000000 0x80000 0x1C0000
nand read 0x82000000 0x80000 0x1C0000

Regards,

RajeeSankar

7563.8bit_nand_error_log.txt

Your NAND device seems to be completely screwed up, almost all initial blocks are bad.

The failure is very obvious here,look at the steps and log,

# specially u-boot

// You erase only until -x1C0000

# nand erase 0x80000 0x1C0000

// Then you attempted to write and then read

# nand write 0x82000000 0x80000 0x1C0000

# nand read 0x82000000 0x80000 0x1C0000

Both will skip the bad blocks and try to read the next valid block, which has not been erased properly before writing. So please erase the NAND area >0x740000, where u-boot is written.

NOTE: Since your NAND device is screwed up completely, I would recommend to use another board here OR try "nand scrub" command. I would not recommend using this command since it is risky, and may lead to software failures and data loss.

Thanks,

Vaibhav

Hi,

Thank you Vaibhav.

I tried with other board.Earlier erase,read and write was proper.

In my code CFG_NAND macro was disabled.So by default it was booting from mmc card.

I enabled the macro and tried nand boot once.It was not working.So once again I went back to the older code .ie disabling CFG_NAND macro.

After that erase not happening,even for the older code.No problem in hardware,because I tried Erase,Read & Write in ccs.It was working there.

In u-boot prompt,I tried erase.It is not happening.Without erasing properly,I can't expect read and write.

It seems something different.Please help me on this.

Thanks.

Regards,

RajeeSankar

Hi,

This is the latest update in nand issue.

By ccs code,I erased the page0 in block0.(Erasing will clean up full page0 with spare area)

At first boot,page0 is good,not marked as a bad block.

I tried to write some data in page0.

It was writing properly and I was able to read.

But after rebooting(mmc boot),page0 marked as bad.

AM3517_CRANE # 

Device 0 bad blocks:

  00000000
  00020000
  00040000
  00060000
  00080000
  000a0000
  000c0000
  000e0000
  00100000
  00120000
  00140000
  00160000
  00180000
  001a0000
  001c0000
  00240000
  16f80000        

page0 in Block0 should not be bad.

Please help me to resolve this.

Thanks in advance.

Regards,

RajeeSankar

HI Rajeesankar,

Have you solved your issue?

Through uboot commnads,

for my second nand flash!

ubifs image adding, writing is proper, but if i read same thing back , getting read error?

Regards,

santosh vastrad

Hi Santosh,

Please check with ECC Layout section in your code.

For me, that was the problem.I was using 8-bit nand.So ECC position should be 1-12.(ie) 0th byte will be used to mark bad blocks.

For 16-bit nand, ECC should be 2-13.(ie) 0th & 1st byte will be used to mark bad blocks.

This mismatching causes read error for me.

Regards,

RajeeSankar

I have x8 NAND connected to am3517 and during debugging u-boot made a lot of mistakes and a IC came with a lot of bad blocks. Do not pay attention to it, just issue the command "nand scrub.chip". The real bad blocks marked by a NAND manufacturer will be in Bad-condition anyway, but your fake-bad blocks will recover.