XIAO

.gitignore

@@ -3,3 +3,8 @@
 !.gitignore
 !flake.nix
 !flake.lock
+
+!xiao-esp32c6/
+!xiao-esp32c6/**
+xiao-esp32c6/.embuild
+xiao-esp32c6/target

flake.lock

@@ -50,6 +50,44 @@
         "type": "github"
       }
     },
+    "espkgs": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs_4"
+      },
+      "locked": {
+        "lastModified": 1738140586,
+        "narHash": "sha256-Vn4PD4eH18QklgDY1vnjXJqNPmP3SJNejcBroW0yTTA=",
+        "owner": "mirrexagon",
+        "repo": "nixpkgs-esp-dev",
+        "rev": "29517b39abe729e04118bf77af526f9947f6c476",
+        "type": "github"
+      },
+      "original": {
+        "owner": "mirrexagon",
+        "repo": "nixpkgs-esp-dev",
+        "type": "github"
+      }
+    },
+    "fenix": {
+      "inputs": {
+        "nixpkgs": "nixpkgs_5",
+        "rust-analyzer-src": "rust-analyzer-src"
+      },
+      "locked": {
+        "lastModified": 1745649180,
+        "narHash": "sha256-3Ptviong+IYr9y3W6ddJMQDn/VpnTQHgwGU3i022HtA=",
+        "owner": "nix-community",
+        "repo": "fenix",
+        "rev": "585fc772cd167cad7d30222b2eb5f5e4bb2166b9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "fenix",
+        "type": "github"
+      }
+    },
     "flake-compat": {
       "flake": false,
       "locked": {
@@ -108,6 +146,24 @@
       "inputs": {
         "systems": "systems"
       },
+      "locked": {
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_2"
+      },
       "locked": {
         "lastModified": 1731533236,
         "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
@@ -237,7 +293,7 @@
     "nixpkgs-python": {
       "inputs": {
         "flake-compat": "flake-compat_2",
-        "nixpkgs": "nixpkgs_5"
+        "nixpkgs": "nixpkgs_7"
       },
       "locked": {
         "lastModified": 1745481253,
@@ -286,6 +342,37 @@
       }
     },
     "nixpkgs_4": {
+      "locked": {
+        "lastModified": 1729501122,
+        "narHash": "sha256-tScdcYQ37kMqlyqb5yizNDTKXZASLB4zHitlHwOg+/o=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "56c7c4a3f5fdbef5bf81c7d9c28fbb45dc626611",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixpkgs-unstable",
+        "type": "indirect"
+      }
+    },
+    "nixpkgs_5": {
+      "locked": {
+        "lastModified": 1745526057,
+        "narHash": "sha256-ITSpPDwvLBZBnPRS2bUcHY3gZSwis/uTe255QgMtTLA=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "f771eb401a46846c1aebd20552521b233dd7e18b",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_6": {
       "locked": {
         "lastModified": 1745526057,
         "narHash": "sha256-ITSpPDwvLBZBnPRS2bUcHY3gZSwis/uTe255QgMtTLA=",
@@ -301,7 +388,7 @@
         "type": "github"
       }
     },
-    "nixpkgs_5": {
+    "nixpkgs_7": {
       "locked": {
         "lastModified": 1719253556,
         "narHash": "sha256-A/76RFUVxZ/7Y8+OMVL1Lc8LRhBxZ8ZE2bpMnvZ1VpY=",
@@ -320,11 +407,30 @@
     "root": {
       "inputs": {
         "devenv": "devenv",
-        "flake-utils": "flake-utils",
+        "espkgs": "espkgs",
-        "nixpkgs": "nixpkgs_4",
+        "fenix": "fenix",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": "nixpkgs_6",
         "nixpkgs-python": "nixpkgs-python"
       }
     },
+    "rust-analyzer-src": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1745591749,
+        "narHash": "sha256-ynI1QfQEMHHuO+hJ8RLzhCo31XLm86vI7zRjKMQ45BQ=",
+        "owner": "rust-lang",
+        "repo": "rust-analyzer",
+        "rev": "df594ba8f4f72064002a4170eea031ba4300f087",
+        "type": "github"
+      },
+      "original": {
+        "owner": "rust-lang",
+        "ref": "nightly",
+        "repo": "rust-analyzer",
+        "type": "github"
+      }
+    },
     "systems": {
       "locked": {
         "lastModified": 1681028828,
@@ -339,6 +445,21 @@
         "repo": "default",
         "type": "github"
       }
+    },
+    "systems_2": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",

flake.nix

@@ -1,6 +1,8 @@
 {
   inputs = {
     devenv.url = "github:cachix/devenv";
+    espkgs.url = "github:mirrexagon/nixpkgs-esp-dev";
+    fenix.url = "github:nix-community/fenix";
     flake-utils.url = "github:numtide/flake-utils";
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     nixpkgs-python.url = "github:cachix/nixpkgs-python";
@@ -9,6 +11,7 @@
   outputs = inputs @ {
     self,
     devenv,
+    espkgs,
     flake-utils,
     nixpkgs,
     ...
@@ -18,6 +21,7 @@
         inherit system;
         config.allowUnfree = true;
       };
+      espPkgs = espkgs.packages.${system};
     in {
       packages = {
         devenv-up = self.devShells.${system}.default.config.procfileScript;
@@ -28,12 +32,33 @@
         inherit inputs pkgs;
         modules = [
           {
+            env = {
+              LIBCLANG_PATH = "${pkgs.llvmPackages.libclang.lib}/lib";
+            };
             git-hooks.hooks.alejandra.enable = true;
             languages = {
               nix.enable = true;
-              rust.enable = true;
+              python.enable = true;
+              rust = {
+                enable = true;
+                channel = "nightly";
+                components = [
+                  "cargo"
+                  "clippy"
+                  "rustc"
+                  "rustfmt"
+                  "rust-analyzer"
+                  "rust-src"
+                ];
+                mold.enable = false;
+              };
               typst.enable = true;
             };
+            packages = with pkgs; [
+              espflash
+              espPkgs.esp-idf-esp32c6
+              ldproxy
+            ];
           }
         ];
       };

xiao-esp32c6/.cargo/config.toml

@@ -0,0 +1,16 @@
+[build]
+target = "riscv32imac-esp-espidf"
+
+[target.riscv32imac-esp-espidf]
+linker = "ldproxy"
+runner = "espflash flash --monitor"
+rustflags = [ "--cfg",  "espidf_time64"]
+
+[unstable]
+build-std = ["std", "panic_abort"]
+
+[env]
+MCU="esp32c6"
+# Note: this variable is not used by the pio builder (`cargo build --features pio`)
+# ESP_IDF_VERSION = "v5.2.3"
+

xiao-esp32c6/Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "xiao-esp32c6"
+version = "0.1.0"
+edition = "2024"
+
+[[bin]]
+name = "xiao-esp32c6"
+harness = false
+
+[build-dependencies]
+embuild = "*"
+
+[dependencies]
+critical-section = { version = "*", features = ["std"] }
+embassy-executor = { version = "*", features = ["arch-std", "executor-thread", "log"] }
+esp-idf-svc = { version = "*", features = ["embassy-time-driver"] }
+log = "*"
+riscv-rt = "*"
+static_cell = "*"
+
+[features]
+default = []
+experimental = ["esp-idf-svc/experimental"]
+
+[profile.release]
+opt-level = "s"
+
+[profile.dev]
+debug = true
+opt-level = "z"
+

xiao-esp32c6/build.rs

@@ -0,0 +1,3 @@
+fn main() {
+    embuild::espidf::sysenv::output();
+}

xiao-esp32c6/sdkconfig.defaults

@@ -0,0 +1,10 @@
+# Rust often needs a bit of an extra main task stack size compared to C (the default is 3K)
+CONFIG_ESP_MAIN_TASK_STACK_SIZE=8000
+
+# Use this to set FreeRTOS kernel tick frequency to 1000 Hz (100 Hz by default).
+# This allows to use 1 ms granularity for thread sleeps (10 ms by default).
+#CONFIG_FREERTOS_HZ=1000
+
+# Workaround for https://github.com/espressif/esp-idf/issues/7631
+#CONFIG_MBEDTLS_CERTIFICATE_BUNDLE=n
+#CONFIG_MBEDTLS_CERTIFICATE_BUNDLE_DEFAULT_FULL=n

xiao-esp32c6/src/bin/xiao-esp32c6.rs

@@ -0,0 +1,16 @@
+#![no_main]
+
+use embassy_executor::Executor;
+use static_cell::StaticCell;
+use xiao_esp32c6::entrypoint;
+
+static EXECUTOR: StaticCell<Executor> = StaticCell::new();
+
+#[unsafe(no_mangle)]
+fn main() {
+    EXECUTOR.init(Executor::new()).run(|spawner| {
+        spawner
+            .spawn(entrypoint(spawner))
+            .expect("Embassy should be able to spawn entrypoint task");
+    });
+}

xiao-esp32c6/src/lib.rs

@@ -0,0 +1,11 @@
+use embassy_executor::Spawner;
+
+#[embassy_executor::task]
+pub async fn entrypoint(_spawner: Spawner) {
+    // It is necessary to call this function once. Otherwise some patches to the runtime
+    // implemented by esp-idf-sys might not link properly. See https://github.com/esp-rs/esp-idf-template/issues/71
+    esp_idf_svc::sys::link_patches();
+
+    // Bind the log crate to the ESP Logging facilities
+    esp_idf_svc::log::EspLogger::initialize_default();
+}