init

flake.nix

@@ -0,0 +1,59 @@
+{
+  inputs = {
+    fenix.url = "github:nix-community/fenix";
+    flake-utils.url = "github:numtide/flake-utils";
+    naersk.url = "github:nix-community/naersk";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+  };
+
+  outputs = { self, fenix, flake-utils, naersk, nixpkgs }:
+    flake-utils.lib.eachDefaultSystem (system:
+      let
+        pkgs = (import nixpkgs) {
+          inherit system;
+        };
+
+        fenix' = fenix.packages.${system}; 
+
+        toolchain = with fenix';
+          combine [
+            minimal.rustc
+            minimal.cargo
+            targets.riscv32imc-unknown-none-elf.latest.rust-std # ESP32-C3 RISC-V
+            targets.riscv32imac-unknown-none-elf.latest.rust-std # ESP32-C3 RISC-V \w atomic emulation
+          ];
+
+        naersk' = naersk.lib.${system}.override {
+          cargo = toolchain;
+          rustc = toolchain;
+        };
+
+      in rec {
+        defaultPackage = packages.riscv32-embedded;
+
+        packages.riscv32-embedded = naersk'.buildPackage rec {
+          src = self;
+
+          depsBuildBuild = with pkgs; [
+            pkgsCross.riscv32-embedded.stdenv.cc
+          ];
+
+          doCheck = true;
+          RUSTFLAGS="-C link-arg=-Tlinkall.x -C force-frame-pointers";
+          # CARGO_UNSTABLE_BUILD_STD = "true";
+          "CARGO_TARGET_${pkgs.lib.toUpper CARGO_BUILD_TARGET}_LINKER" = "riscv32-none-elf-gcc";
+          "CARGO_TARGET_${pkgs.lib.toUpper CARGO_BUILD_TARGET}_RUNNER" = "espflash --monitor";
+          CARGO_BUILD_TARGET = "riscv32imc-unknown-none-elf";
+          shellHook = ''
+
+          '';
+        };
+
+        devShell = with pkgs; mkShell ({
+          RUST_SRC_PATH = "${fenix'.complete.rust-src}/lib/rustlib/src/rust/library";
+          nativeBuildInputs = [ toolchain cargo-espmonitor cargo-espflash ] ++ defaultPackage.depsBuildBuild;
+        } // (lib.filterAttrs (name: _: lib.hasPrefix "CARGO_" name || lib.hasPrefix "RUST" name) defaultPackage));
+      }
+    );
+}
+