dd: no value specified for seek

[0xPetra]

dd: no value specified for seek

I'm getting this error while trying to run this command:

xxd -p -c 100000 PREFIX_keyfile | xxd -r -p | dd of=nrf52_firmware.bin skip=1 bs=1 seek=$(grep -oba OFFLINEFINDINGPUBLICKEYHERE! nrf52_firmware.bin | cut -d ':' -f 1) conv=notrunc

I also tried running grep and got nothing as a response:

grep -oba OFFLINEFINDINGPUBLICKEYHERE! nrf52_firmware.bin | cut -d ':' -f 1

I compiled the .bin files again. Something that I need clarification on is how this command would look for a string in a binary file.

I tried replacing OFFLINEFINDINGPUBLICKEYHERE! with the actual PUB KEY (which doesn't make sense), but I still did it.

What could be happening? Appreciate the repo!

[dchristl]

Hello @0xPetra,

the output of the grep command should be 155224, if the firmware is untouched.

Two possible issues, if this doesn't work:

1. Your firmware is already patched, because dd works directly with the original bin without a copy. The solution is to redownload the binary
2. You are not working with a posic compatible shell (bash, zsh, sh, ..) and the command works not as expected. The solution is to use another shell or post the shell you using.

Kind regards, Danny

[0xPetra]

I'm using zsh, so it should work.

Sorry to ask such a simple question, but where should I download it from?

Besides compiling my own version I also downloaded from here: https://github.com/acalatrava/openhaystack-firmware/tree/main/apps/openhaystack-alternative/compiled

Thanks! Cheers, Petra

[dchristl]

I'm using zsh, so it should work.

Do you use it on Linux or Mac? It seems Mac has an issue with grep. Please try to set the LC_CTYPE env variable before the command, i.e.:

LC_CTYPE=C grep -oba OFFLINEFINDINGPUBLICKEYHERE! nrf52_firmware.bin | cut -d ':' -f 1

resp.

LC_CTYPE=C xxd -p -c 100000 PREFIX_keyfile | xxd -r -p | dd of=nrf52_firmware.bin skip=1 bs=1 seek=$(grep -oba OFFLINEFINDINGPUBLICKEYHERE! nrf52_firmware.bin | cut -d ':' -f 1) conv=notrunc

Sorry to ask such a simple question, but where should I download it from?

You should use the version from this project at the release page

[0xPetra]

Oh, I didn't realize about releases. After making sure everything works, I can update the Readme with some notes.

Indeed I'm using a Mac. LC_CTYPE=C does work for grep, printing 155224, which is the expected value as you mentioned. But the second command still throws an error with the new .bin:

dd: no value specified for seek

Tried this (LC_CTYPE=C in seek):

LC_CTYPE=C xxd -p -c 100000 PREFIX_keyfile | xxd -r -p | dd of=nrf52_firmware.bin skip=1 bs=1 seek=$(LC_CTYPE=C grep -oba OFFLINEFINDINGPUBLICKEYHERE! nrf52_firmware.bin | cut -d ':' -f 1) conv=notrunc

And got this response:

28+0 records in
28+0 records out
28 bytes transferred in 0.000152 secs (184211 bytes/sec)

Now, time to flash and see!

[dchristl]

I've updated the README, to execute the command on non -GNU shells. The changes should work for Linux and Mac.

[0xPetra]

It does seem to work.

I also needed to make it a .hex with this command: arm-none-eabi-objcopy -I binary -O ihex nrf52_firmware.bin nrf52_firmware.hex

I still can't flash my nRF52 Dongle, though. I'm using the Programmer app from nRF Connect, and "Write" is disabled with the patched firmware.

I thought maybe SoftDevice was missing and tried to add it separately. But it overlaps with the firmware, so I guess it was indeed included while compiling.

Any idea what might be going on?

Thanks in advance! Really appreciate the responses!

[dchristl]

arm-none-eabi-objcopy -I binary -O ihex nrf52_firmware.bin nrf52_firmware.hex

I'm not familar with the programmer app, you are using, but this shouldn't be needed normally. I flash the firmware with opeonocd, that works really well. The commands and the openocd.cfg file is in the docs. Maybe you have to change the last line openocd.cfg from

source [find target/nrf51.cfg] to source [find target/nrf52.cfg], but I don't think this is really needed.

Can you try it with openocd?

I thought maybe SoftDevice was missing and tried to add it separately. But it overlaps with the firmware, so I guess it was indeed included while compiling.

You are right, the softdevice is already included.