Cross-compiling

Lighthouse supports cross-compiling, allowing users to run a binary on one platform (e.g., aarch64) that was compiled on another platform (e.g., x86_64).

Instructions

Cross-compiling requires Docker, rustembedded/cross and for the current user to be in the docker group.

The binaries will be created in the target/ directory of the Lighthouse project.

Targets

The Makefile in the project contains four targets for cross-compiling:

  • build-x86_64: builds an optimized version for x86_64 processors (suitable for most users).
  • build-x86_64-portable: builds a version for x86_64 processors which avoids using some modern CPU instructions that are incompatible with older CPUs.
  • build-aarch64: builds an optimized version for 64-bit ARM processors (suitable for Raspberry Pi 4).
  • build-aarch64-portable: builds a version for 64-bit ARM processors which avoids using some modern CPU instructions. In practice, very few ARM processors lack the instructions necessary to run the faster non-portable build.

For more information about optimized vs portable builds see Portability.

Example

cd lighthouse
make build-aarch64

The lighthouse binary will be compiled inside a Docker container and placed in lighthouse/target/aarch64-unknown-linux-gnu/release.

Feature Flags

When using the makefile the set of features used for building can be controlled with the environment variable CROSS_FEATURES. See Feature Flags for available features.

Compilation Profiles

When using the makefile the build profile can be controlled with the environment variable CROSS_PROFILE. See Compilation Profiles for available profiles.