Add rustup toolchain file

flake.lock

@@ -1,18 +1,20 @@
 {
   "nodes": {
-    "mozilla-overlay": {
-      "flake": false,
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
       "locked": {
-        "lastModified": 1638887313,
-        "narHash": "sha256-FMYV6rVtvSIfthgC1sK1xugh3y7muoQcvduMdriz4ag=",
-        "owner": "mozilla",
-        "repo": "nixpkgs-mozilla",
-        "rev": "7c1e8b1dd6ed0043fb4ee0b12b815256b0b9de6f",
+        "lastModified": 1705309234,
+        "narHash": "sha256-uNRRNRKmJyCRC/8y1RqBkqWBLM034y4qN7EprSdmgyA=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "1ef2e671c3b0c19053962c07dbda38332dcebf26",
         "type": "github"
       },
       "original": {
-        "owner": "mozilla",
-        "repo": "nixpkgs-mozilla",
+        "owner": "numtide",
+        "repo": "flake-utils",
         "type": "github"
       }
     },
@@ -34,11 +36,32 @@
     },
     "root": {
       "inputs": {
-        "mozilla-overlay": "mozilla-overlay",
         "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay",
         "src-migen": "src-migen"
       }
     },
+    "rust-overlay": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1713924823,
+        "narHash": "sha256-kOeyS3GFwgnKvzuBMmFqEAX0xwZ7Nj4/5tXuvpZ0d4U=",
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "rev": "8a2edac3ae926a2a6ce60f4595dcc4540fc8cad4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oxalica",
+        "repo": "rust-overlay",
+        "type": "github"
+      }
+    },
     "src-migen": {
       "flake": false,
       "locked": {
@@ -54,6 +77,21 @@
         "repo": "migen",
         "type": "github"
       }
+    },
+    "systems": {
+      "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

@@ -2,16 +2,15 @@
   description = "Firmware for MQTT-controlled 4-channel DDS signal generator using Urukul, Humpback and STM32 NUCLEO.";
 
   inputs.nixpkgs.url = github:NixOS/nixpkgs/nixos-21.11;
-  inputs.mozilla-overlay = { url = github:mozilla/nixpkgs-mozilla; flake = false; };
+  inputs.rust-overlay.url = github:oxalica/rust-overlay;
+  inputs.rust-overlay.inputs.nixpkgs.follows = "nixpkgs";
   inputs.src-migen = { url = github:m-labs/migen; flake = false; };
 
-  outputs = { self, nixpkgs, mozilla-overlay, src-migen }:
+  outputs = { self, nixpkgs, rust-overlay, src-migen }:
     let
-      pkgs = import nixpkgs { system = "x86_64-linux"; overlays = [ (import mozilla-overlay) ]; };
-      rustManifest = pkgs.fetchurl {
-        url = "https://static.rust-lang.org/dist/2020-10-30/channel-rust-nightly.toml";
-        sha256 = "0iygcwzh8s0lfdghj5809krvzifc1ii1wm4sd3qqn7s0rz1s14hi";
-      };
+      pkgs = import nixpkgs { system = "x86_64-linux"; overlays = [ (import rust-overlay) ]; };
+
+      rustToolchain = pkgs.rust-bin.fromRustupToolchainFile ./rust-toolchain.toml;
 
       migen = pkgs.python3Packages.buildPythonPackage rec {
         name = "migen";
@@ -19,21 +18,10 @@
         propagatedBuildInputs = [ pkgs.python3Packages.colorama ];
       };
 
-      targets = [
-        "thumbv7em-none-eabihf"
-      ];
-      rustChannelOfTargets = _channel: _date: targets:
-        (pkgs.lib.rustLib.fromManifestFile rustManifest {
-          inherit (pkgs) stdenv lib fetchurl patchelf;
-          }).rust.override {
-          inherit targets;
-          extensions = ["rust-src"];
+      rustPlatform = pkgs.makeRustPlatform {
+        rustc = rustToolchain;
+        cargo = rustToolchain;
       };
-      rust = rustChannelOfTargets "nightly" null targets;
-      rustPlatform = pkgs.recurseIntoAttrs (pkgs.makeRustPlatform {
-        rustc = rust;
-        cargo = rust;
-      });
 
       itm = rustPlatform.buildRustPackage rec {
         version = "0.3.1";

rust-toolchain.toml

@@ -0,0 +1,6 @@
+[toolchain]
+channel = "nightly-2020-10-30"
+targets = [
+  "thumbv7em-none-eabihf",
+]
+profile = "minimal"