init basic examples and setup

flake.nix

@@ -0,0 +1,55 @@
+{
+  description = "Rust on STM32";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.05";
+    rust-overlay.url = "github:oxalica/rust-overlay";
+  };
+
+  outputs = {
+    self,
+    flake-utils,
+    nixpkgs,
+    rust-overlay,
+  }:
+    flake-utils.lib.eachDefaultSystem (system: let
+      pkgs = import nixpkgs {
+        inherit system;
+        overlays = [(import rust-overlay)];
+      };
+
+      rustToolchain =
+        pkgs.rust-bin.stable."1.95.0".default.override {
+          extensions = [
+            "clippy"
+            "llvm-tools-preview"
+            "rust-src"
+            "rustfmt"
+          ];
+          targets = [
+            "thumbv7m-none-eabi"
+            "thumbv6m-none-eabi"
+          ];
+        };
+    in {
+      devShells.default = pkgs.mkShell {
+        packages = [
+          rustToolchain
+          pkgs.cargo-binutils
+          pkgs.flip-link
+          pkgs.just
+          pkgs.llvmPackages.bintools
+          pkgs.probe-rs
+        ];
+
+        RUST_SRC_PATH = "${rustToolchain}/lib/rustlib/src/rust/library";
+
+        shellHook = ''
+          echo "Rust on STM32 dev shell"
+          echo "Default target: thumbv7m-none-eabi"
+          echo "Flash and run commands use PROBE_RS_CHIP if you need to override the default."
+        '';
+      };
+    });
+}