Building Heads

With the new Nix build system, building Heads has become more streamlined.

Please refer to the Building Heads section in the Heads README for updated instructions on how to build Heads using the Nix build system’s produced docker image reproducibly.

For more information, you can also check out the pull request #1661 which provides additional details and updates to the build process.

Clone the tree:

git clone https://github.com/osresearch/heads
cd heads

Builds of Heads should be reproducible unless issues are currently known, see Heads milestone #1 for more detail, which means that Heads will build in the exact same way on different computers. Because of this, as a user, you can guarantee that Heads has built correctly and has not been tampered with.

However, this also means that the first time you build Heads it must first build the compilers that it will use to build itself. If that seems complicated, don’t worry. The result is that the first build of Heads will take about an hour to complete. After the first build, building Heads will take less than a minute.

Useful targets, stored under the boards directory of the git tree.

Generic

Generally, everything that is needed to flash the SPI flash of a board is a single rom generated through make BOARD=$BOARD commands, where $BOARD is the name of the board that can be found under board directory of the git downloaded tree. You can do the build verbose by doing make BOARD=$BOARD V=1

You can also run make in debug mode to trace errors in the buildsystem while you try to improve it through make -d BOARD=$BOARD V=1

Make Heads for another board (XXX should be the name of your board in ./boards and YY the number of CPUs you want to build with):

 ./docker_repro.sh make BOARD=XXX CPUS=YY

The resulting rom file for a x86 board will be either ./build/x86/XXX/XXX.rom or ./build/x86/XXX/heads-XXX-vYYYY-gZZZZZZZ.rom (XXX should be the name of your board in ./boards, vYYYY the pinned Heads version and ZZZZZZ the commit id from which your build comes from).

Please continue to the corresponding flashing guide for your device.

More options and detail about Heads modules under Makefile