feat(rust-esp32-c6): make the rust-esp32-c6 template

flake.nix

@@ -34,6 +34,7 @@
       imports = [
         ./cad
         ./rust
+        ./rust-esp32-c6
 
         flake-parts.flakeModules.flakeModules
         # define the flake.templates option

rust-esp32-c6/default.nix

@@ -0,0 +1,44 @@
+{
+  flake-parts-lib,
+  inputs,
+  self,
+  ...
+}: {
+  flake = {
+    templates = {
+      rust-esp32-c6 = {
+        path = ./template;
+        description = "ESP32-C6 RISC-V rust project with a blink led example";
+      };
+    };
+
+    flakeModules.rust-esp32-c6 = {
+      imports = [
+        inputs.treefmt-nix.flakeModule
+        self.outputs.flakeModules.rust
+      ];
+
+      options.perSystem = flake-parts-lib.mkPerSystemOption ({
+        lib,
+        config,
+        pkgs,
+        self',
+        ...
+      }: let
+        cfg = config.krantz.rust.esp32-c6;
+
+        craneLib = config.krantz.rust.craneLib;
+      in {
+        options.krantz.rust.esp32-c6 = {
+          enable = lib.mkEnableOption "additional tooling for the esp32 RISC-V";
+        };
+
+        config = lib.mkIf cfg.enable {
+          krantz.rust.devDeps = lib.mkOptionDefault (with pkgs; [
+            espflash
+          ]);
+        };
+      });
+    };
+  };
+}

rust-esp32-c6/template/.cargo/config.toml

@@ -0,0 +1,17 @@
+[target.riscv32imac-unknown-none-elf]
+runner = "espflash flash --monitor --chip esp32c6 --log-format defmt"
+
+[env]
+DEFMT_LOG="info"
+
+[build]
+rustflags = [
+  # Required to obtain backtraces (e.g. when using the "esp-backtrace" crate.)
+  # NOTE: May negatively impact performance of produced code
+  "-C", "force-frame-pointers",
+]
+
+target = "riscv32imac-unknown-none-elf"
+
+[unstable]
+build-std = ["alloc", "core"]

rust-esp32-c6/template/.clippy.toml

@@ -0,0 +1 @@
+stack-size-threshold = 1024

rust-esp32-c6/template/.envrc

@@ -0,0 +1 @@
+use flake

rust-esp32-c6/template/.gitea/workflows/flake-update.yaml

@@ -0,0 +1,30 @@
+name: "Flake.lock: update Nix dependencies for development environment only"
+
+on:
+  workflow_dispatch: # allows manual triggering
+  schedule:
+    - cron: '00 00 02 1/2 *' # runs the first of day the month every 2 months at 7:00pm local time (midnight UTC)
+
+jobs:
+  nix-flake-update:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: "install nix"
+        uses: cachix/install-nix-action@v31
+
+      - name: "setup git user"
+        uses: fregante/setup-git-user@v2
+
+      - name: "update flake.lock"
+        run: |
+          nix flake update --commit-lock-file
+
+      - name: "check flake for errors"
+        run: |
+          nix flake check
+
+      - name: "push update"
+        run: |
+          git push

rust-esp32-c6/template/.gitignore

@@ -0,0 +1,23 @@
+# Generated by nix
+.direnv/
+result
+
+# Generated by Cargo
+# will have compiled files and executables
+debug/
+target/
+
+# Editor configuration
+.vscode/
+.zed/
+.helix/
+.nvim.lua
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+# Ignore .DS_Store file in mac
+**/.DS_Store

rust-esp32-c6/template/Cargo.toml

@@ -0,0 +1,48 @@
+[package]
+edition      = "2024"
+name         = "rust-esp32-c6"
+rust-version = "1.88"
+version      = "0.1.0"
+
+[[bin]]
+name = "rust-esp32-c6"
+path = "./src/bin/main.rs"
+
+[dependencies]
+esp-hal = { version = "~1.1.0", features = ["defmt", "esp32c6", "unstable"] }
+
+esp-rtos = { version = "0.3.0", features = [
+  "defmt",
+  "embassy",
+  "esp-alloc",
+  "esp32c6",
+] }
+
+defmt                  = "1.0.1"
+esp-bootloader-esp-idf = { version = "0.5.0", features = ["defmt", "esp32c6"] }
+
+embassy-executor = { version = "0.10.0", features = ["defmt"] }
+embassy-time = { version = "0.5.0", features = ["defmt"] }
+esp-alloc = { version = "0.10.0", features = ["defmt"] }
+esp-backtrace = { version = "0.19.0", features = [
+  "defmt",
+  "esp32c6",
+  "panic-handler",
+] }
+esp-println = { version = "0.17.0", features = ["defmt-espflash", "esp32c6"] }
+
+critical-section = "1.2.0"
+static_cell      = "2.1.1"
+
+
+# For fine tuning these settings, please refer to https://doc.rust-lang.org/cargo/reference/profiles.html
+[profile.dev]
+# The default debug profile is too slow and too big for resource-constrained devices.
+# Always build with some optimizations enabled.
+opt-level = "s"
+
+[profile.release]
+codegen-units = 1     # LLVM can perform better optimizations using a single thread
+debug         = 2     # prefer slower builds but better debugging experience
+lto           = 'fat'
+opt-level     = 's'

rust-esp32-c6/template/build.rs

@@ -0,0 +1,71 @@
+fn main() {
+    linker_be_nice();
+    println!("cargo:rustc-link-arg=-Tdefmt.x");
+    // make sure linkall.x is the last linker script (otherwise might cause problems with flip-link)
+    println!("cargo:rustc-link-arg=-Tlinkall.x");
+}
+
+fn linker_be_nice() {
+    let args: Vec<String> = std::env::args().collect();
+    if args.len() > 1 {
+        let kind = &args[1];
+        let what = &args[2];
+
+        match kind.as_str() {
+            "undefined-symbol" => match what.as_str() {
+                what if what.starts_with("_defmt_") => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `defmt` not found - make sure `defmt.x` is added as a linker script and you have included `use defmt_rtt as _;`"
+                    );
+                    eprintln!();
+                }
+                "_stack_start" => {
+                    eprintln!();
+                    eprintln!("💡 Is the linker script `linkall.x` missing?");
+                    eprintln!();
+                }
+                what if what.starts_with("esp_rtos_") => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `esp-radio` has no scheduler enabled. Make sure you have initialized `esp-rtos` or provided an external scheduler."
+                    );
+                    eprintln!();
+                }
+                "embedded_test_linker_file_not_added_to_rustflags" => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 `embedded-test` not found - make sure `embedded-test.x` is added as a linker script for tests"
+                    );
+                    eprintln!();
+                }
+                "free"
+                | "malloc"
+                | "calloc"
+                | "get_free_internal_heap_size"
+                | "malloc_internal"
+                | "realloc_internal"
+                | "calloc_internal"
+                | "free_internal" => {
+                    eprintln!();
+                    eprintln!(
+                        "💡 Did you forget the `esp-alloc` dependency or didn't enable the `compat` feature on it?"
+                    );
+                    eprintln!();
+                }
+                _ => (),
+            },
+            // we don't have anything helpful for "missing-lib" yet
+            _ => {
+                std::process::exit(1);
+            }
+        }
+
+        std::process::exit(0);
+    }
+
+    println!(
+        "cargo:rustc-link-arg=--error-handling-script={}",
+        std::env::current_exe().unwrap().display()
+    );
+}

rust-esp32-c6/template/flake.nix

@@ -0,0 +1,42 @@
+{
+  description = "esp32 tool";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+
+    flake-parts.url = "github:hercules-ci/flake-parts";
+
+    project-templates = {
+      url = "git+https://git.krantz.one/reed/project-templates";
+      inputs.nixpkgs.follows = "nixpkgs";
+      inputs.flake-parts.follows = "flake-parts";
+    };
+  };
+
+  outputs = {
+    flake-parts,
+    project-templates,
+    ...
+  } @ inputs:
+    flake-parts.lib.mkFlake {inherit inputs;} {
+      imports = [
+        project-templates.flakeModules.rust-esp32-c6
+      ];
+
+      systems = ["aarch64-linux" "x86_64-linux" "aarch64-darwin"];
+
+      perSystem = {pkgs, ...}: {
+        krantz.rust = {
+          esp32-c6 = {
+            enable = true;
+          };
+
+          enable = true;
+          src = ./.;
+
+          # runtimeDeps = with pkgs; [];
+          # buildDeps = with pkgs; [];
+        };
+      };
+    };
+}

rust-esp32-c6/template/rust-toolchain.toml

@@ -0,0 +1,4 @@
+[toolchain]
+channel    = "stable"
+components = ["rust-src"]
+targets = ["riscv32imac-unknown-none-elf"]

rust-esp32-c6/template/src/bin/main.rs

@@ -0,0 +1,54 @@
+#![no_std]
+#![no_main]
+#![deny(
+    clippy::mem_forget,
+    reason = "mem::forget is generally not safe to do with esp_hal types, especially those \
+    holding buffers for the duration of a data transfer."
+)]
+#![deny(clippy::large_stack_frames)]
+
+use defmt::info;
+use embassy_executor::Spawner;
+use embassy_time::{Duration, Timer};
+use esp_backtrace as _;
+use esp_hal::clock::CpuClock;
+use esp_hal::timer::timg::TimerGroup;
+use esp_println as _;
+
+extern crate alloc;
+
+// This creates a default app-descriptor required by the esp-idf bootloader.
+// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
+esp_bootloader_esp_idf::esp_app_desc!();
+
+#[allow(
+    clippy::large_stack_frames,
+    reason = "it's not unusual to allocate larger buffers etc. in main"
+)]
+#[esp_rtos::main]
+async fn main(spawner: Spawner) -> ! {
+    // generator version: 1.3.0
+    // generator parameters: --chip esp32c6 -o alloc -o unstable-hal -o esp-backtrace -o embassy -o defmt
+
+    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
+    let peripherals = esp_hal::init(config);
+
+    esp_alloc::heap_allocator!(#[esp_hal::ram(reclaimed)] size: 65536);
+
+    let timg0 = TimerGroup::new(peripherals.TIMG0);
+    let sw_interrupt =
+        esp_hal::interrupt::software::SoftwareInterruptControl::new(peripherals.SW_INTERRUPT);
+    esp_rtos::start(timg0.timer0, sw_interrupt.software_interrupt0);
+
+    info!("Embassy initialized!");
+
+    // TODO: Spawn some tasks
+    let _ = spawner;
+
+    loop {
+        info!("Hello world!");
+        Timer::after(Duration::from_secs(1)).await;
+    }
+
+    // for inspiration have a look at the examples at https://github.com/esp-rs/esp-hal/tree/esp-hal-v1.1.0/examples
+}

rust-esp32-c6/template/src/lib.rs

@@ -0,0 +1 @@
+#![no_std]