Unbricking

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Revision as of 11:29, 28 September 2007 by Philipp (talk | contribs) (New page: == Prerequisites == In order to recover a bricked radio, you will need a JTAG cable, software for flashing over JTAG, and an image to flash to the radio. As yet, noone has successfully fin...)
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Prerequisites

In order to recover a bricked radio, you will need a JTAG cable, software for flashing over JTAG, and an image to flash to the radio. As yet, noone has successfully finished this process, so this is a documentation of progress so far.

JTAG Cables

'Wiggler' compatible cables are a popular low-cost cable, and well supported by the free jtag tools. Plans to make your own are widely available, and prebuilt ones can be found cheaply on ebay and similar sites. A "universal" wiggler will come with bare wires which can be soldered to the [Media:Barracuda-board-outline.jpg jtag test points] on the barracuda board.

JTAG Flashing Software

The following possibilities are being explored.

  • OpenOCD Support for NAND flash via the S3C2410's built in controller can be added by adapting this patch to support the K9F2808U0C fitted to the barracuda module with some as yet undiscovered minor changes.
  • jtager Seems to support the S3C2410 out of the box, but not as widely used as the above so documentation is even more difficult to find than the above two (which is already a bit of a black art).
  • sjf2410 Used by the OpenMoko project, looks promising if you already have a flash image, but only seems to support writing to flash.
  • jflash-s3c2410 is mentioned on many webpages, especially Chinese ones, and seems to have been freely downloadable in the past, but it seems to only be shipped with S3C2410 dev boards now.

Image

The following are possible sources for an image to flash.

  • A previously created backup.
  • If you know what caused the bricking, you could read the partition from flash, fix the problem and write it back.
  • The sharpfin system image (work in progress)

Required information

  • Memory map. We need to know the base address of the flash, and possibly other information.
  • Partition map. This is available in the file drivers/mtd/nand/nand_rirm2.c in the reciva kernel sources.