Partial migration of cross-compilation from `cross` to Cargo.

Cargo.toml

@@ -17,7 +17,22 @@ yaml_serde = "0.10"
 zip = "8.3"
 
 [profile.dev]
-opt-level = 3
+opt-level = 1
 
 [profile.release]
 opt-level = 3
+
+[target.aarch64-unknown-linux-gnu]
+cc = "aarch64-linux-gnu-gcc"
+cxx = "aarch64-linux-gnu-g++"
+ar = "aarch64-linux-gnu-ar"
+# ranlib = "aarch64-linux-gnu-ranlib"
+linker = "aarch64-linux-gnu-gcc"
+
+
+[target.arm-unknown-linux-gnueabihf]
+cc = "arm-linux-gnueabihf-gcc"
+cxx = "arm-linux-gnueabihf-g++"
+ar = "arm-linux-gnueabihf-ar"
+# ranlib = "arm-linux-gnueabihf-ranlib"
+linker = "arm-linux-gnueabihf-gcc"

Cross.toml

@@ -1,8 +0,0 @@
-[build]
-default-target = "aarch64-unknown-linux-gnu"   # use this target if none is explicitly provided
-pre-build = [                                  # additional commands to run prior to building the package
-    "dpkg --add-architecture $CROSS_DEB_ARCH", 
-    "apt update",
-    "apt --assume-yes install apt-utils:$CROSS_DEB_ARCH",
-    "apt --assume-yes install libsdl3-dev:$CROSS_DEB_ARCH"
-]                 

readme.md

@@ -6,21 +6,28 @@
 
 ## Install ARM toolchains:
 
-```
-cargo install cross
-rustup target add aarch64-unknown-linux-gnu   # 64-bit Pi OS
-rustup target add armv7-unknown-linux-gnueabihf  # 32-bit Pi 2/3/4 OS
-rustup target add arm-unknown-linux-gnueabihf    # ARMv6 (Pi Zero/1)
+```bash
+$ rustup target add aarch64-unknown-linux-gnu
+$ rustup target add arm-unknown-linux-gnueabihf
 
-sudo apt-get update
-sudo apt-get install gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf
+
+$ sudo dpkg --add-architecture arm64
+$ sudo dpkg --add-architecture armhf
+
+$ sudo apt update 
+$ sudo apt-get install gcc-aarch64-linux-gnu gcc-arm-linux-gnueabihf \
+                       libc6-arm64-cross libc6-dev-arm64-cross gcc-aarch64-linux-gnu \
+                       libc6-armhf-cross libc6-dev-armhf-cross gcc-arm-linux-gnueabihf \
+                       libssl-dev libssl-dev:arm64 libsdl3-dev:arm64 libssl-dev:armhf libsdl3-dev:armhf
 ```
 
 ## Cross-compile
 
-```
-# 2) Build
-~/.cargo/bin/cross build --target aarch64-unknown-linux-gnu --release
-~/.cargo/bin/cross build --target armv7-unknown-linux-gnueabihf --release
-~/.cargo/bin/cross build --target arm-unknown-linux-gnueabihf --release
+ARM64
+```bash
+$ export PKG_CONFIG_SYSROOT_DIR=/usr/aarch64-linux-gnu/
+$ cargo build --target aarch64-unknown-linux-gnu --release
+
+$ export PKG_CONFIG_SYSROOT_DIR=/usr/arm-linux-gnueabihf/
+$ cargo build --target arm-unknown-linux-gnueabihf --release
 ```