From d9b42a0807ab9c3cb13a8567e868bca89186693c Mon Sep 17 00:00:00 2001
From: Sebastien Bourdeauducq <sb@m-labs.hk>
Date: Sun, 9 Jun 2019 00:05:40 +0800
Subject: [PATCH] clean up firmware compilation

---
 firmware/default.nix | 8 ++------
 overlay.nix          | 3 ++-
 2 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/firmware/default.nix b/firmware/default.nix
index c9bc25d..12373b3 100644
--- a/firmware/default.nix
+++ b/firmware/default.nix
@@ -1,4 +1,4 @@
-{ rustPlatform, rust-riscv32i-crates, binutils-riscv32, rustc, cargo }:
+{ rustPlatform, rust-riscv32i-crates, binutils-riscv32 }:
 
 rustPlatform.buildRustPackage rec {
   name = "helloworld";
@@ -7,14 +7,10 @@ rustPlatform.buildRustPackage rec {
   src = ./.;
   cargoSha256 = "0kf2pnfylfmzm0qvi4jfci43qvrnj1v5f037sb9zpvfqyddhdffl";
 
-  # HACK - rustc overlay does not update rustPlatform. Find out why.
-  configurePhase = ''echo XXX ${rustPlatform.rust.rustc} ${rustPlatform.rust.cargo}'';
-
   buildPhase = ''
     export CARGO_HOME=$(mktemp -d cargo-home.XXX)
     export RUSTFLAGS="-L ${rust-riscv32i-crates}/lib/rustlib/riscv32i-unknown-none-elf/lib -C linker=${binutils-riscv32}/bin/riscv32-unknown-elf-ld -C link-arg=-Tlink.x"
-    export RUSTC=${rustc}/bin/rustc
-    ${cargo}/bin/cargo build --release --target riscv32i-unknown-none-elf
+    cargo build --release --target riscv32i-unknown-none-elf
   '';
 
   doCheck = false;
diff --git a/overlay.nix b/overlay.nix
index b5ea8a6..a3b4d80 100644
--- a/overlay.nix
+++ b/overlay.nix
@@ -1,5 +1,5 @@
 self: super:
-{
+rec {
   llvm_7 = super.llvm_7.overrideAttrs(oa: {
     name = oa.name + "-riscv";
     cmakeFlags = oa.cmakeFlags ++ ["-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=RISCV"];
@@ -7,4 +7,5 @@ self: super:
   rustc = super.rustc.overrideAttrs(oa: {
     patches = oa.patches ++ [ ./compilers/rustc-riscv32i.patch ];
   });
+  rustPlatform = super.makeRustPlatform { inherit rustc; inherit (super) cargo; };
 }