Category: Hardware

Flipper Zero “Transmission is blocked” Unlock Sub-GHz region restriction by compiling your own firmware

Posted on by OtakuBear

For firmware version: stable 0.71.1

Use the Docker container of the Flipper Zero toolchain as the compile environment.

docker pull flipperdevices/flipperzero-toolchain
docker run -it flipperdevices/flipperzero-toolchain bash

Get the official Flipper Zero firmware source code. 

git clone https://github.com/flipperdevices/flipperzero-firmware.git

Get into the directory 

cd flipperzero-firmware

Two files are needed to be modified to unlock region tx restrictions:

First, in ./assets/resources/subghz/assets you need to create a file named as Settings_User. Just copy the same file from the Rogue Master repo.

Rogue Master firmware repository

https://github.com/RogueMaster/flipperzero-firmware-wPlugins
wget -P ./assets/resources/subghz/assets https://github.com/RogueMaster/flipperzero-firmware-wPlugins/raw/420/assets/resources/subghz/assets/setting_user.txt

Second, the file named furi_hal_subghz.c located in ./firmware/targets/f7/furi_hal. In the code block beginning from line 278, comment out the “if” line by adding “//” at the beginning.

bool furi_hal_subghz_tx() {
// if(furi_hal_subghz.regulation != SubGhzRegulationTxRx) return false;
furi_hal_spi_acquire(&furi_hal_spi_bus_handle_subghz);
cc1101_switch_to_tx(&furi_hal_spi_bus_handle_subghz);
furi_hal_spi_release(&furi_hal_spi_bus_handle_subghz);
return true;
}

But there is no vim or nano in this container, so you need to edit it on the host machine.

mv firmware/targets/f7/furi_hal/furi_hal_subghz.c firmware/targets/f7/furi_hal/furi_hal_subghz.c.backup
#detach from container press ctrl+p then ctrl+q
#on host machine
docker ps
docker cp container_id:/flipperzero-firmware/firmware/targets/f7/furi_hal/flipper-z-f7-full-local.dfu.backup ./
mv furi_hal_subghz.c.backup furi_hal_subghz.c
#edit furi_hal_subghz.c as mentioned
docker cp ./furi_hal_subghz.c container_id:/flipperzero-firmware/firmware/targets/f7/furi_hal
#go back to conainer
docker attach container_id

Run command ./fbt to compile the firmware. When finished you will find the firmware file in ./dist directory.

To copy the firmware from the container to the host machine, run this command on the host machine.

docker cp container_id:/flipperzero-firmware/dist/f7-D/flipper-z-f7-full-local.dfu ./

Reference

Flipper zero: Build your own firmware!

Youtube Channel MugAMuggle