Add compilation section with cross-compilation instructions

src/SUMMARY.md

@@ -17,6 +17,7 @@
     - [peach-stats](./software/microservices/peach-stats.md)
   - [Web Interface](./software/web_interface.md)
   - [Pattern Library](./software/pattern_library.md)
+  - [Compilation](./software/compilation.md)
   - [Packaging](./software/packaging.md)
   - [Configuration](./software/configuration.md)
 - [Contributor's Guide](./contributors_guide.md)

src/software/compilation.md

@@ -0,0 +1,38 @@
+# Compilation
+
+Since the majority of PeachCloud is written in the Rust programming language, a compiler and associated toolchain(s) is required to build the software from source. Visit the [rustup](https://rustup.rs/) website to download the Rust toolchain installer. In addition to the default `stable` installation of Rust, many PeachCloud crates require the `nightly` toolchain channel in order to compile. Instructions for installing and updating toolchains can be found in the README of the [rustup GitHub repo](https://github.com/rust-lang/rustup).
+
+## Cross-Compilation
+
+While PeachCloud crates can be compiled directly on the Raspberry Pi or equivalent single board computer, this process is resource intensive and relatively slow - especially when compiling release builds. Cross-compilation is an effective means of leveraging greater compute resources to reduce compilation time.
+
+These instructions cover cross-compilation for Debian Buster running on a Raspberry Pi 3B+, using a host machine running Debian Stretch with an x86_64 architecture:
+
+**Install target platform:**
+
+`rustup target add aarch64-unknown-linux-gnu`
+
+**Install toolchain:**
+
+`rustup toolchain install nightly-aarch64-unknown-linux-gnu`
+
+**Install aarch64-linux-gnu-gcc:**
+
+`sudo apt-get install gcc-aarch64-linux-gnu`
+
+**Configure the linker:**
+
+`export CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=/usr/bin/aarch64-linux-gnu-gcc`
+
+Alternatively, create a file named `cargo-config` in the root directory of the crate and add the following:
+
+```bash
+[target.aarch64-unknown-linux-gnu]
+linker = "aarch64-linux-gnu-gcc"
+```
+
+**Compile release build:**
+
+`cargo build --release --target=aarch64-unknown-linux-gnu`
+
+The generated binary will be saved at `target/aarch64-unknown-linux-gnu/release/name_of_crate`