My embedded device is not working after updating firmware. Thus I tried to update firmware using u-boot. I could successfully get u-boot console via serial connection, but updating firmware failed due to the lack of knowledge on firmware update using u-boot.

At last, I not only corrupted linux kernel but also u-boot while modifying the device flash memory (u-boot command supports flash memory modification). Booting device no longer gives u-boot console. It just stops (I can see it through the serial connection).

In this situation, how can I recover(or update) firmware on my device?

closed as unclear what you're asking by Networker, Anthon, strugee, Gilles, Volker Siegel Sep 17 '14 at 1:29

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  • This question appears to be off-topic because it is about embedded computing. – strugee Sep 16 '14 at 21:07
  • 1
    @strugee Being about embedded computing doesn't make a question off-topic here. However, the fact that the problem occurs before the bootloader runs does. This question also lacks information: what kind of device is this, and what kind of memory is the firmware stored on? – Gilles Sep 16 '14 at 21:27
  • @Gilles I know, I didn't know how to phrase it. you've done a better job. – strugee Sep 16 '14 at 21:28

If available (ie. if there's a JTAG header on your board) , you can connect using a JTAG cable.

Remember: Before using it you might need to enable JTAG using Test Mode Select Input (sometimes a jumper somewhere).

You can then use that connection to upload a new firmware into your device.

  • Could you let me know useful link for JTAG tutorial? – freddy Sep 19 '14 at 6:49

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