unbrick armStoneA8 after wrong nand write command.

  • Hi,

    after executing by mistake 'nand write . Kernel 0 $(filesize)' with Zero before file size, u-boot broke the hardware The command I suppose flashed the kernel binary at offset '0' in NAND memory. As the result, the board is not booting anymore. Nothing is send out to serial port; pressing 's' button at power-up didn't work. looks like the board is dead.

    Is there any way of unbricking the board? Is NBOOT is accessable somehow?

    Thank you.

  • First of all, pressing 's' is not as simple as the standard "any key" when U-Boot starts normally. The 's' must be pressed during a rather short time period at startup. Therefore we recommend setting the keyboard repeat rate to maximum and then press and hold 's' and while 's' is repeatedly sent to the board, switch the power on. You may even have to try it several times. But if there is never any reaction, then you have hit the jackpot and yes, then NBoot is gone. Then you have to send in the board to F&S after getting an RMA. The linked page will tell you whether the board can be sent in directly or must be sent via your distributor.

    I'm still trying to figure out how this could happen. If you insert the zero at this place, then it is used as the size, i.e. as the number of bytes to write, and the $(filesize) is ignored. But a size of zero is caught, it should not go through to writing any data (where the 0 might be wrongly interpreted as 4GB). In addition we have a software write protection in place that should reject any writing to the low sectors of the NAND flash. To modify NBoot in the current U-Boot version, you even have to write to a completely different NAND device, as the flash is virtually split into two devices. So I'm completely puzzled how this was possible.

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

  • Honestly to say, I'm puzzled too. Theoretically u-boot must protect NBOOT section. At least I would expect such behaviour.
    NBOOT has software update feature integrated, thereofre there is no need to make whose NAND addresses writable.

    BTW, what would be the cost of repairing? Does it makes sense to fillout RMA, or would be chipper to order new board?

    Thank you.

    Best Regards

  • Here I'm puzzled too. Your RMA page gives me following error:
    Diese Seriennummer ist nicht in unserem System registriert. Bitte überprüfen Sie ob Sie die richtige Seriennummer eingegeben haben.

    FYI: I'm sure this board is not a fake. :) An the serial number is correct entered.

    Best regards