Braiins OS is a fully open-source operating system for ASIC miners. It was the first firmware to implement overt AsicBoost in 2018, and it now features an implementation of the new mining protocol, Stratum V2. Additionally, Braiins OS works in tandem with our new software component, BOSminer, which we've written from scratch in Rust language as a replacement for the outdated CGminer.

Currently supported devices are Bitmain’s Antminer S9, S9i, and S9j. Antminer S17 support is planned for the near future.


  • Open-source operating system

  • Stratum V2 implementation with improved data efficiency and hashrate hijacking prevention

  • CGminer replacement (BOSminer) written from scratch in Rust language

  • Quick startup (5-7 seconds)

  • No random crashes due to undefined behavior

  • Bulk installation

  • Automatic updates with the standard opkg system

  • Fully customizable fan control (enables immersion cooling)

  • Advanced monitoring to prevent overheating and other issues

Support and Contact

Have questions? Our dev and support teams are always available to help.

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This release covers mostly user facing issues, installation/deinstalation difficulties and 1 major problem with I2C controller on S9's. Also, we now have nightly builds that are easy to enable via bos tool.

  • All mining hardware types

    • [feature] support for reconnect - we have implemented support for client.reconnect (stratum V1) and reconnect message for V2

    • [feature] installation/deinstallation (aka upgrade2bos and restore2factory) process (transition from factory firmware to Braiins OS or vica versa) has been improved:

    • [feature] custom pool user (--pool-user) can be set on command line

    • [feature] pool settings from the factory firmware are now automatically being migrated to BOSminer configuration. Migration can be disabled by specifying (--no-keep-pools)

    • [feature] we now provide binary form of upgrade2bos (based on pyinstaller) that contains the latest Braiins OS installation image

    • [feature] similarly, restore2factory (based on pyinstaller) is now available in binary form and doesn't require any longer downloading/finding out the correct factory firmware.

    • [feature] disk space and time consuming backup of the original firmware is now disabled by default (can be enabled by --backup)

    • [feature] keeping host name while performing first time install is now driving by 2 options --keep-hostname and --no-keep-hostname allowing to force override and automatic hostname generation based on MAC address

    • [feature] support for enabling/disabling nightly builds has been integrated into bos utility (and its legacy miner counterpart).

    • [feature] system now provides logs covering longer timespan of BOSminer operation due to enabling log rotation and compression of '/var/log/syslog.old' when it is bigger than 32 KiB

    • [bug] SD card image now contains slushpool authority public key that was missing

    • [bug] rejection rate is now correctly being displayed

    • [bug] unknown stratum V1 messages received from the server are now being logged for diagnostics

  • Antminer S9

    • [bug] some devices were experiencing random I2C controller bus lockups and would fail to communicate with hashboard power controllers connected to the shared I2C bus. We have found out that the cause was the Xilinx I2C controller core that we have integrated into the FPGA bitstream. We have switched to the I2C present in the SoC and the bitstream only routes the signal of the peripheral (IIC0) to corresponding FPGA pins.


See WHATSNEW.MD on github

Known Issues

The following lists issues that are known to be present in released version.

20.03 (Updated 3/30/2020)

  • GUI

  • Reference line in hashrate chart has incorrect value for average nominal hashrate. Issue only present when less than 3 hash chains are operational.

  • Rejection ratio is multiplied by 100. As an example, when rejection rate is 0.1%, then 10% will be shown.

  • Configuration

    • SD Card installation will report missing Stratum V2 authentication key in the Miner/Configuration section (Error: missing upstream authority key for securing stratum2+tcp connection in pool"). User can configure connection (including the key) in the configuration, or directly in the /etc/bosminer.toml file.