stm32: remove the mozilla overlay, build with rust 1.32.4-stable

resulting binaries lack important sections.

stm32/default.nix

@@ -1,13 +1,18 @@
-{ # Use master branch of the overlay by default
-  mozillaOverlay ? import (builtins.fetchTarball https://github.com/mozilla/nixpkgs-mozilla/archive/master.tar.gz),
-  rustManifest ? builtins.fetchurl "https://static.rust-lang.org/dist/channel-rust-nightly.toml"
+{ pkgs ? import (builtins.fetchGit { url = git://github.com/NixOS/nixpkgs-channels; }) {},
 }:
 
+with pkgs;
 let
-  pkgs = import <nixpkgs> { overlays = [ mozillaOverlay ]; };
-  rustPlatform = pkgs.recurseIntoAttrs (pkgs.callPackage ./rustPlatform.nix {
-    inherit rustManifest;
-  });
+  rust-thumb-crates = callPackage ./rust-thumb-crates.nix { inherit (rustPlatform.rust) rustc; };
+  llvm-rust-src = fetchFromGitHub {
+    owner = "rust-lang";
+    repo = "llvm-project";
+    rev = "rustc/8.0-2019-03-18";
+    sha256 = "0lvlf76yyjk61wl1y6l83w84g8y06vz4mwjcxwxcgdmh480ha8vb";
+  };
+  lld = llvmPackages_8.lld.override {
+    fetch = name: _sha256: builtins.toPath "${llvm-rust-src}/${name}";
+  };
   buildStm32Firmware = { name, src, cargoSha256 }:
     rustPlatform.buildRustPackage rec {
       inherit name;
@@ -15,10 +20,14 @@ let
 
       inherit src cargoSha256;
 
+      buildInputs = [ lld ];
       buildPhase = ''
         export CARGO_HOME=$(mktemp -d cargo-home.XXX)
-        cargo build --release
+        export RUSTFLAGS="-L ${rust-thumb-crates}/lib/rustlib/thumbv7em-none-eabihf/lib -C linker-flavor=ld.lld -C linker=lld"
+        cargo build --release -v -v
       '';
+      dontStrip = true;
+      dontPatchELF = true;
 
       doCheck = false;
       installPhase = ''
@@ -37,6 +46,6 @@ in
     thermostat = buildStm32Firmware {
       name = "thermostat";
       src = <thermostatSrc>;
-      cargoSha256 = "1i9p5d5n01ajbp8lmavyway6vr1mmy107qnccff9glvr91rqx352";
+      cargoSha256 = "1xbnd2j4akdf3fc62frb74vpghspkr58kbya2gyzqqdj2gfzy8dh";
     };
   }

stm32/rustPlatform.nix

@@ -1,23 +0,0 @@
-{ recurseIntoAttrs, stdenv, lib,
-  makeRustPlatform,
-  fetchurl, patchelf,
-  rustManifest ? ./channel-rust-nightly.toml
-}:
-
-let
-  targets = [
-    "thumbv7em-none-eabihf"
-  ];
-  rustChannel =
-    lib.rustLib.fromManifestFile rustManifest {
-      inherit stdenv fetchurl patchelf;
-    };
-  rust =
-    rustChannel.rust.override {
-      inherit targets;
-    };
-in
-makeRustPlatform {
-  rustc = rust;
-  cargo = rust;
-}