cargo generate from https://github.com/lulf/embassy-template.git

southbridge/.cargo/config.toml

@@ -0,0 +1,8 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+runner = "probe-rs run --chip RP2040"
+
+[build]
+target = "thumbv6m-none-eabi"
+
+[env]
+DEFMT_LOG = "info"

southbridge/Cargo.toml

@@ -0,0 +1,25 @@
+[package]
+edition = "2021"
+name = "southbridge"
+version = "0.1.0"
+authors = ["Andy Killorin <37423245+Speedy6451@users.noreply.github.com>"]
+resolver = "2"
+
+[dependencies]
+defmt = "0.3"
+defmt-rtt = "0.4"
+panic-probe = { version = "0.3", features = ["print-defmt"] }
+
+embedded-hal = "1.0.0"
+embedded-hal-async = "1.0.0"
+embedded-io = "0.6.1"
+embedded-io-async = "0.6.1"
+embedded-storage = "0.3.1"
+
+cortex-m-rt = "0.7.3"
+
+embassy-executor = { version = "0.7", features = ["task-arena-size-1024", "arch-cortex-m", "executor-thread", "defmt", "executor-interrupt"] }
+embassy-sync = { version = "0.6" }
+embassy-time = { version = "0.4", features = ["defmt", "defmt-timestamp-uptime"] }
+cortex-m = { version = "0.7.6" }
+embassy-rp = { version = "0.3", features = ["defmt", "unstable-pac", "time-driver", "critical-section-impl", "rp2040"] }

southbridge/build.rs

@@ -0,0 +1,36 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink.x");
+    println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+println!("cargo:rustc-link-arg-bins=-Tlink-rp.x");
+}

southbridge/memory.x

@@ -0,0 +1,7 @@
+MEMORY
+{
+BOOT2   : ORIGIN = 0x10000000, LENGTH = 0x100
+FLASH : ORIGIN = 0x10000100, LENGTH = 2048K - 0x100
+  RAM : ORIGIN = 0x20000000, LENGTH = 264K
+}
+

southbridge/rust-toolchain.toml

@@ -0,0 +1,10 @@
+# Before upgrading check that everything is available on all tier1 targets here:
+# https://rust-lang.github.io/rustup-components-history
+[toolchain]
+channel = "stable"
+components = [ "rustfmt" ]
+targets = [
+    "thumbv6m-none-eabi",
+    "thumbv7em-none-eabihf",
+    "riscv32imac-unknown-none-elf",
+]

southbridge/src/main.rs

@@ -0,0 +1,15 @@
+#![no_std]
+#![no_main]
+
+use embassy_executor::Spawner;
+use embassy_time::{Duration, Timer};
+use {defmt_rtt as _, panic_probe as _};
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let _p = embassy_rp::init(Default::default());
+    loop {
+        defmt::info!("Blink");
+        Timer::after(Duration::from_millis(100)).await;
+    }
+}