Upgrade Firmware

Current Version

Older releases, the source code, and much more be found in our repository on github.

Background

The upgrade menu allows your to load updated firmware onto the Coldcard.

advanced menu

The menu allows loading a upgrade file from a MicroSD card, but it can also be done using the command line tool, or from the Electrum plugin.

Upgrade Functions

Show Version
Displays the version numbers that you have already.
From MicroSD
Select an upgrade file from MicroSD card and start the process.
Bless Firmware
Mark the contents of flash memory as "approved" and light the green "Genuine" light.

Upgrade Files

You need a DFU file for upgrades. It's about 690k in size and should have the extension .dfu.

The latest firmware will always be available in Github:

github.com/Coldcard/.../releases

All upgrade files must be signed by a Coinkite Inc approved key.

Downgrade Protection

In general, it may not be possible to downgrade (return to an older release). Some releases will set a "high water mark" so the bootloader that will block any downgrade to earlier versions. We will do this if a bug or security problem with an obsolete release is identifed.