11.1. Prerequisites¶

This target uses the LLVM ld.lld linker but to locate the system C libraries required to link a functional Linux binary, this target drives the ld.lld linker using your system’s C compiler as a linker driver.

You must have a C compiler which:

• Supports -fuse-ld=ld.lld option to select ld.lld as the linker

• Supports -B option to modify the tool search path so it can find Ferrocene’s copy of ld.lld

• Does not load plugins into the linker (e.g. the GCC LTO plugin)

• Supplies to ld.lld only those linker arguments specified in the Safety Manual

On Ubuntu 20.04 LTS you can install a suitable C compiler with:

$ sudo apt install gcc

11.2. Archives to install¶

The following archives are needed when installing this target as a host platform:

• rustc-x86_64-unknown-linux-gnu

• rust-std-x86_64-unknown-linux-gnu

• ferrocene-self-test-x86_64-unknown-linux-gnu

The following archives are needed when installing this target as a cross-compilation target:

• rust-std-x86_64-unknown-linux-gnu

To install the optional rustfmt tool, the following archive is needed:

• rustfmt-x86_64-unknown-linux-gnu

11.3. Required compiler flags¶

To use the target, the following additional flags must be provided to rustc:

• --target=x86_64-unknown-linux-gnu

• -C linker=<your-c-compiler>

  • e.g. -C linker=/usr/bin/gcc

If your C compiler loads the GCC LTO plugins by default, you will also need to switch off GCC LTO with:

• -Clink-arg=-fno-lto