Soekris net6501, Error, Incorrect signature of BIOS image

I writing this article because it takes some time to find a solution for my problem. There is a reboot / freeze bug in the firmware 2.40a of the Soekris BIOS. After an reboot of the system the BIOS freezes with the output:

POST: 012345

So i started to update the BIOS version to 2.41a. The upload to the board works but the flashupdate return an error.

> download -

Start sending file using XMODEM/CRC protocol.
### Send (x) b6501_141a.bin: 253696 bytes, 2:34 elapsed, 1645 cps, 14%

File downloaded succesfully, size 1982 Blocks.

> flashupdate

Error, Incorrect signature of BIOS image.

The Solution is easy but hard to find. Using the uManager, a ARM based out-of-band management. Follow the instructions to update the BIOS:

  • Type ‘+++’ just after the board is powered up in the console. Pressing the reset button for more than 3 seconds to power down the board.
  • Use “download -” to update the BIOS.
  • Follow the instructions from the Soekris Wiki for the Xmodem settings.

Helpful answer from Luc in the mailing list and some information for the uManager BIOS update.