Table of contents
Heads is supposed to be a reproducible build and as of v0.1.0 it achieved this goal. The downside is that the initial build can take a very long time as it downloads and builds all of the its dependencies. One issue right now is that it builds not just one, but two cross compilers and as a result takes about 45 minutes. Luckily subsequent builds only take about 30 seconds to produce a full coreboot and Linux ROM image, but that first ones a doozy…
Heads buils should be fully reproducible on any Linux-ish system (OSX build is not supported). If you don’t get the same hashes as reported on the release page, please file an issue against the reproducible build milestone.
With a vanilla Debian 9 or Ubuntu 16.04 install, such as a digitalocean droplet, you need to first install some support tools. This takes a short while, so get a cup of coffee and install host build requirements packages as specified here
On a Fedora machine, install host build requirements packages as specified here.
For emulation and analysis with UEFITool, install
dnf install -y qemu qt5-devel
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
board directory of the git tree.
Generated roms are generally found under build/$BOARD/$BOARD.rom
Generally, everything that is needed to flash the SPI flash of a board is a single rom generated through
make BOARD=$BOARD command, where $BOARD is the name of the board that can be found under
board directory of the git downloaded tree.
Make Heads for another board (
XXX should be the name of your board in ./boards):
The resulting rom file will be either
XXX should be the name of your board in
Some boards have a two SPI flash chip configuration and need special care.
For the Thinkpad x230 there are two boards in
./boards, x230-flash and x230. x230-flash is externally flashable and contains a smaller package that will let us boot to the Heads recovery shell. x230 is only internally flashable and contains all of Heads. Since we will end up using both x230-flash and x230, it makes the most sense to build both now.
x230 boards needs their 4MB SPI2 to be initially externally flashed, while the 12MB rom needs to be flashed internally from within Heads to make sure to not screw up with ME, contained in the SPI1 flash (8MB bottom flash chip under keyboard)
The following make command generates a self-contained, externally flashable rom for the SPI2 (4MB BIOS, top SPI flash under keyboard).
Resulting rom is found under build/x230-flash/x230-flash.rom
The following make command will generate a 12MB
coreboot.rom under the build/x230 directory.
coreboot.rom is the one needed to flash rom updates from within Heads in respect of ME. This is done with the help of the
flashrom-x230.sh script from Heads recovery shell.
Please continue to the corresponding flashing guide for your device.
More options and detail about Heads modules under Makefile