This firmware had been copied and modified from trezor-mcu under the GNU LGPL. Please refer to the README.md file on that repository for extra details about bootloader and firmware compilation.
This code aims at tranforming the cipher library from this repository into firmware for the STM32 hardware.
On GNU/Linux it is possible to download the official compressed tarball, extract it , and add it to system PATH as follows
wget https://developer.arm.com/-/media/Files/downloads/gnu-rm/6-2017q2/gcc-arm-none-eabi-6-2017-q2-update-linux.tar.bz2
tar xjf gcc-arm-none-eabi-6-2017-q2-update-linux.tar.bz2
export PATH="$PWD/gcc-arm-none-eabi-6-2017-q2-update/bin:$PATH"Some distributions offer binary installation packages . For instance, on Ubuntu>=14.04
sudo apt-get install gcc-arm-none-eabiOn Mac OS, after installing homebrew it is recommended to install the toolchain like this
brew tap skycoin/homebrew-skycoin
brew update
brew install gcc-arm-none-eabi-63ST-LINK tool is needed to send JTAG commands to the Skycoin hardware wallet.
Binaries are available for installing ST-LINK using native package managers.
For instance, on Mac OS X the following command will install stlink and its dependencies.
brew install stlink
If this option is not available for the platform of your preference then install from sources by following the steps here.
On Debian and Ubuntu GNU/Linux
sudo apt-get install protobuf-compiler python-protobuf golang-goprotobuf-dev
On Mac OS
brew install protobuf
go get -u github.com/golang/protobuf/{proto,protoc-gen-go}
If no binaries are available for your platform then
- Install Protobuf C++ runtime and protoc from sources.
- Install Protobuf Python runtime from sources.
- Install Protobuf Go runtime from sources.
We need to tell your kernel to use the hidraw module to communicate with the hardware device. If you don't your kernel will treat the device as a mouse or a keyboard.
Run sudo ./prepare-sky-hw.sh.
Create a file named 99-dev-kit.rules in your /etc/udev/rules.d/ folder and write this content in that file (super user priviledges are required for this step).
## 0483:df11 STMicroelectronics STM Device in DFU Mode
SUBSYSTEM=="usb", ATTR{idVendor}=="0483", ATTR{idProduct}=="df11", MODE="0666"
## 0483:3748 STMicroelectronics ST-LINK/V2
SUBSYSTEM=="usb", ATTR{idVendor}=="0483", ATTR{idProduct}=="3748", MODE="0666"
## 0483:374b STMicroelectronics ST-LINK/V2.1 (Nucleo-F103RB)
SUBSYSTEM=="usb", ATTR{idVendor}=="0483", ATTR{idProduct}=="374b", MODE="0666"
## 313a:0001
SUBSYSTEM=="usb", ATTR{idVendor}=="313a", ATTR{idProduct}=="0001", MODE="0666"
KERNEL=="hidraw*", ATTRS{idVendor}=="313a", ATTRS{idProduct}=="0001", MODE="0666"
Restart your machine or force your udev kernel module to reload the rules.
sudo udevadm control --reload-rules
sudo udevadm trigger
[Optional] If you want to compile with a inverted screen and inverted buttons set REVERSE_SCREEN and REVERSE_BUTTONS environment variable to 1 :
export REVERSE_SCREEN=1
export REVERSE_BUTTONS=1 # need to be changed in the project Makefile if you are using it
Disable the signature checking
Change SIGNATURE_PROTECT to 0 in the project Makfile
You can check the device is seen by your ST-LINK using this command:
st-info --probe
To flash a full firmware build at FULL_FIRMWARE_PATH on a microcontroller of STM32f2xx family the command is:
st-flash write ${FULL_FIRMWARE_PATH} 0x08000000;
It is also possible to use the st-flash rule in the main Makefile. If FULL_FIRMWARE_PATH not set it's value defaults to ./full-firmware-no-mem-protect.bin, which happens to be the output of make full-firmware command.
We are compiling a modified version of trezor original firmware. The bootloader we are using is configured to detect it and warn the user about this. We are still in developpement steps, this warning is acceptable. The devices allows the user to skip the warning but during that time the OS of the host computer may miss the opportunity to load the driver to communicate with the device.
If when you plug the device your OS is not seeing the device, skip the warning on device's screen saying that the signature is wrong and then try this.
If you are fast enough you can also quickly click the button "accept" on the device when the warning about wrong firmware signature appears.
The system stores five public keys and expects three signatures issued from one of these public keys.
The public keys are hardwritten in the bootloader's source code in file signatures.c
The signatures are also present in firmware_sign.py script, in the "pubkeys" array.
See README.md: Run make sign from repository home.
The command line tool will ask you in which of the three slots do you want to store the signature.
The it will ask you to provide a secret key that must correspond to one of the five public keys stored in the bootloader and the script as described above.
See README.md: Run make full-firmware from repository home.
Then you can re-flash the firmware for instance with st-skycoin alias.
Check here for golang code example communicating with the device.
Feel free to hack main.go file.
You can also try the trezorctl python based command line.
The communication between PC and firmware is a master/slave model where the firmware is slave. It reacts to messages but cannot initiate a communication. The messages are defined using google protobuf code generation tools. The same file messages.proto can be copy pasted elswhere to generate the same structures in other coding languages.
The repository provides examples to communicate with the device using golang.
The firmware has two components: the bootloader and the firmware. The bootloader main role is to check firmware's signature in order to warn user in case the detected firmware is not the official firmware distributed by skycoin.
Here is a quick presentation of most important files of the firmware:
- protob/messages.proto: defines all the messages received the firmware can receive and their structure
- firmware/fsm.c: all the messages received in the firmware correspond to a call to a function in fsm.c, the corresponding between messages and function is defined in protob/messages_map.h (generated file)
- firmware/storage.c: manages the persistent (persistent when pluging out the power supply) memory of the firmware.
- oled.c/layout.c: manage screen display
- firmware/skywallet.c: main entry point
On bootloader side it is worth mentioning:
- signatures.c: checks the firmware's signature matches skycoin's public keys
If you get SDL errors you might want to install these:
sudo apt-get install libsdl2-dev libsdl2-image-dev
If you can't install sdl packages using 'apt install' on an ubuntu based linux distribution (had the problem on linux mint) you can download them from these urls:
- https://packages.ubuntu.com/bionic-updates/libsdl2-dev
- https://packages.ubuntu.com/bionic/libsdl2-2.0-0
Works also with docker if you run the script:
./build-emulator.sh