website docs on targets

Author: alphaville

docs/python-advanced.md

@@ -99,8 +99,10 @@ build_config.with_build_mode(
     og.config.BuildConfiguration.RELEASE_MODE)
 ```
 
+### Cross-compilation 
+
 You can either compile for your own system, or cross-compile for a 
-different target system. For example, to cross-compile for a Raspberry Pi,
+different target system. For example, to cross-compile for a **Raspberry Pi**,
 set the following option
 
 ```python
@@ -113,8 +115,63 @@ or
 build_config.with_target_system("rpi")  # Raspberry Pi
 ```
 
-Note that you need to install the necessary target first.
+Note that you need to install the necessary target first. 
+
+<details>
+<summary><b>See setup details</b></summary>
+To cross-compile for a Raspberry Pi you need to run the following in your terminal
+
+```bash
+rustup target add arm-unknown-linux-gnueabihf
+```
+
+On Linux you also need the following dependencies
+
+```bash
+sudo apt-get update
+sudo apt-get install -y gcc-arm-linux-gnueabihf libc6-dev-armhf-cross
+```
+
+On MacOS, do the following
+
+```bash
+# Tap the repository that provides the cross-compiler
+brew tap messense/macos-cross-toolchains
+# Update brew to ensure the tap is recognized (can sometimes be needed)
+brew update 
+# Install the full toolchain (includes gcc, binutils, sysroot)
+# This specific formula provides the entire toolchain.
+brew install arm-unknown-linux-gnueabihf 
+
+# Verify the compiler is found
+which arm-linux-gnueabihf-gcc || (echo "arm-linux-gnueabihf-gcc not found in PATH" && exit 1)
+```
+</details>
+
+If you need to compile for a target other than `arm-linux-gnueabihf-gcc` (`rpi`)
+some manual configuration may be needed (you may need to install the target 
+and/or a compiler/linker) and you may need to edit the auto-generated 
+`.cargo/config.toml` files you will find in your auto-generated solvers. 
+
+<details>
+<summary><b>Non-supported targets</b></summary>
+The auto-generated `.cargo/config.toml` files contain entries like
+
+```toml
+[target.arm-unknown-linux-gnueabihf]
+linker="arm-linux-gnueabihf-gcc"
+```
+
+Here you may have to insert manually your own target. 
+Feel free to open an [issue](https://github.com/alphaville/optimization-engine/issues) 
+on GitHub if you would like us to add support for a particular target (create a feature
+request); see the [contributing guidelines](https://alphaville.github.io/optimization-engine/docs/contributing).
+</details>
+
+
+### Other build options
 
+All build options are shown below
 
 | Method                        | Explanation                                 |
 |-------------------------------|---------------------------------------------|