Coldcard Wallet

Coldcard is a Cheap, Ultra-secure & Verifiable Hardware Wallet for Bitcoin. Get yours at Coldcard.com

Follow @COLDCARDwallet on Twitter to keep up with the latest updates and security alerts.

Reproducible Builds

To have confidence this source code tree is the same as the binary on your device, you can rebuild it from source and get exactly the same bytes. This process has been automated using Docker. Steps are as follows:

Install Docker and start it.
Install make (GNUMake) if you don't already have it.
Checkout the code, and start the process.

git clone https://github.com/Coldcard/firmware.git

cd firmware/stm32

make repro
At the end of the process a clear confirmation message is shown, or the differences.
Build products can be found firmware/stm32/built.

Check-out and Setup

NOTE This is the master branch and covers the latest hardware (Mk4). See branch v4-legacy for firmware which supports only Mk3/Mk2 and earlier.

Do a checkout, recursively to get all the submodules:

git clone --recursive https://github.com/Coldcard/firmware.git

Already checked-out and getting git errors? Do this:

git fetch
git reset --hard origin/master

Do not use a path with any spaces in it. The Makefiles do not handle that well, and we're not planning to fix it.

Then:

cd firmware
git submodule update --init (if needed?)
brew install automake autogen virtualenv
virtualenv -p python3 ENV (Python > 3.5 is required)
source ENV/bin/activate (or source ENV/bin/activate.csh based on shell preference)
pip install -r requirements.txt

Setup and Run the Desktop-based Coldcard simulator:

cd unix; make setup && make && ./simulator.py

Building the firmware:

cd ../cli; pip install --editable .
cd ../stm32; make setup && make; make firmware-signed.dfu
The resulting file, firmware-signed.dfu can be loaded directly onto a Coldcard, using this command (already installed based on above)
ckcc upgrade firmware-signed.dfu

Which looks like this:

[ENV] [firmware/stm32 42] ckcc upgrade firmware-signed.dfu
675328 bytes (start @ 293) to send from 'firmware-signed.dfu'
Uploading  [##########--------------------------]   29%  0d 00:01:04

MacOS

You'll probably need to install at least these packages:

brew install --cask xquartz
brew install sdl2 xterm
brew install --cask gcc-arm-embedded

Used to be these were needed as well:

brew tap PX4/px4
brew search px4
brew install px4/px4/gcc-arm-none-eabi-80 (latest gcc-arm-none-eabi-XX, currently 80)

You may need to reboot to avoid a DISPLAY is not set error.

You may need to brew upgrade gcc-arm-embedded because we need 10.2 or higher.

Big Sur Issues

defaults write org.python.python ApplePersistenceIgnoreState NO will supress a warning about Python[22580:10101559] ApplePersistenceIgnoreState: Existing state will not be touched. New state will be written to... see https://bugs.python.org/issue32909

Linux

You'll probably need to install these (Ubuntu 16):

apt install libudev-dev python-sdl2 gcc-arm-none-eabi

If you get stuck on the "Skip PIN" screen after the startup, edit the pyb.py file located under /unix/frozen-modules/ and follow the instructions from line 27 to line 31:

# If on linux, try commenting the following line
addr = bytes([len(fn)+2, socket.AF_UNIX] + list(fn))
# If on linux, try uncommenting the following two lines
#import struct
#addr = struct.pack('H108s', socket.AF_UNIX, fn)

Code Organization

Top-level dirs:

shared

shared code between desktop test version and real-deal
expected to be largely in python, and higher-level
new code found only on the Mk4 will be listed in manifest_mk4.py code exclusive to earlier hardware is in manifest_mk3.py

unix

unix (MacOS) version for testing/rapid dev
this is a simulator for the product

testing

test cases and associated data

stm32

embedded binaries (and building), for actual product hardware
final target is a binary file for loading onto hardware

external

code from other projects, ie. the dreaded submodules

graphics

images which ship as part of the final product (icons)

stm32/bootloader

32k of factory-set code that you cannot change (Mk3)
however, you can inspect what code is on your coldcard and compare to this.

stm32/mk4-bootloader

128k of factory-set code that you cannot change for Mk4
however, you can inspect what code is on your coldcard and compare to this.

hardware

schematic and bill of materials for the Coldcard

unix/work/...

/MicroSD/* files on "simulated" microSD card
/VirtDisk/* simulated emulated virtual Disk files.
/settings/*.aes persistant settings for Simulator

Support

Found a bug? Email: support@coinkite.com

Ademan/coldcard-firmware