working example with fixed flake

.gitignore

@@ -0,0 +1,49 @@
+# === Rust / Cargo ===
+/target/
+/**/target/
+/**/*.rlib
+**/*.d
+**/*.rlib
+**/*.rmeta
+
+# === Nix / Flakes ===
+result
+.nix-result
+.nix-gcRoots
+.direnv
+.envrc
+.nix-hidden
+
+# === Editor / IDE ===
+# VSCode
+.vscode/
+# IntelliJ / CLion / RustRover
+.idea/
+*.iml
+# Emacs
+*~
+.#*
+# Vim
+*.swp
+*.swo
+
+# === Logs and Dumps ===
+*.log
+*.out
+*.err
+
+# === OS Junk ===
+.DS_Store
+Thumbs.db
+
+# === ESP build junk ===
+esp-idf/
+.espressif/
+*.elf
+*.bin
+*.uf2
+*.app
+*.map
+
+
+flake.lock

flake.nix

@@ -25,21 +25,25 @@
         espup
       ];
 
-      shellHook = ''
+shellHook = ''
-        echo ">>> ESP32 DevShell (esp-hal only)"
+  echo ">>> ESP32 DevShell (esp-hal only)"
 
-        if [ ! -d "$HOME/.espup" ]; then
+  if [ ! -d "$HOME/.espup" ]; then
-          echo "Running espup install..."
+    echo "Running espup install..."
-          espup install
+    espup install
-        fi
+  fi
 
-        # Activate Xtensa Rust toolchain
+  # Activate Xtensa Rust toolchain
-        export RUSTUP_TOOLCHAIN=esp
+  export RUSTUP_TOOLCHAIN=esp
-        export PATH=$HOME/.rustup/toolchains/esp/bin:$PATH
+  export PATH=$HOME/.rustup/toolchains/esp/bin:$PATH
 
-        echo "Xtensa Rust toolchain ready."
+  # Add GCC/binutils path for xtensa-esp32-elf-gcc
-        rustc --version
+  export PATH=$HOME/.rustup/toolchains/esp/xtensa-esp-elf/esp-14.2.0_20240906/xtensa-esp-elf/bin:$PATH
-      '';
+
+  echo "Xtensa Rust toolchain ready."
+  rustc --version
+  which xtensa-esp32-elf-gcc || echo "⚠️ xtensa-esp32-elf-gcc not found in PATH"
+'';
     };
   };
 }

test1/.cargo/config.toml

@@ -0,0 +1,16 @@
+[target.xtensa-esp32-none-elf]
+runner = "espflash flash --monitor --chip esp32"
+
+[env]
+ESP_LOG="info"
+
+[build]
+rustflags = [
+  "-C", "link-arg=-nostartfiles",
+  "-Z", "stack-protector=all",
+]
+
+target = "xtensa-esp32-none-elf"
+
+[unstable]
+build-std = ["alloc", "core"]

test1/.gitignore

@@ -0,0 +1,19 @@
+# will have compiled files and executables
+debug/
+target/
+.vscode/
+.zed/
+.helix/
+
+# These are backup files generated by rustfmt
+**/*.rs.bk
+
+# MSVC Windows builds of rustc generate these, which store debugging information
+*.pdb
+
+# RustRover
+#  JetBrains specific template is maintained in a separate JetBrains.gitignore that can
+#  be found at https://github.com/github/gitignore/blob/main/Global/JetBrains.gitignore
+#  and can be added to the global gitignore or merged into this file.  For a more nuclear
+#  option (not recommended) you can uncomment the following to ignore the entire idea folder.
+#.idea/

test1/Cargo.toml

@@ -0,0 +1,81 @@
+[package]
+edition      = "2021"
+name         = "test1"
+rust-version = "1.86"
+version      = "0.1.0"
+
+[[bin]]
+name = "test1"
+path = "./src/bin/main.rs"
+
+[dependencies]
+esp-bootloader-esp-idf = { version = "0.2.0", features = ["esp32"] }
+esp-hal = { version = "=1.0.0-rc.0", features = [
+  "esp32",
+  "log-04",
+  "unstable",
+] }
+log = "0.4.27"
+
+embassy-net = { version = "0.7.0", features = [
+  "dhcpv4",
+  "log",
+  "medium-ethernet",
+  "tcp",
+  "udp",
+] }
+embedded-io = "0.6.1"
+embedded-io-async = "0.6.1"
+esp-alloc = "0.8.0"
+esp-backtrace = { version = "0.17.0", features = [
+  "esp32",
+  "exception-handler",
+  "panic-handler",
+  "println",
+] }
+esp-println = { version = "0.15.0", features = ["esp32", "log-04"] }
+# for more networking protocol support see https://crates.io/crates/edge-net
+critical-section = "1.2.0"
+embassy-executor = { version = "0.7.0", features = [
+  "log",
+  "task-arena-size-20480",
+] }
+embassy-time = { version = "0.4.0", features = ["log"] }
+esp-hal-embassy = { version = "0.9.0", features = ["esp32", "log-04"] }
+esp-wifi = { version = "0.15.0", features = [
+  "builtin-scheduler",
+  "esp-alloc",
+  "esp32",
+  "log-04",
+  "smoltcp",
+  "wifi",
+] }
+smoltcp = { version = "0.12.0", default-features = false, features = [
+  "log",
+  "medium-ethernet",
+  "multicast",
+  "proto-dhcpv4",
+  "proto-dns",
+  "proto-ipv4",
+  "socket-dns",
+  "socket-icmp",
+  "socket-raw",
+  "socket-tcp",
+  "socket-udp",
+] }
+static_cell = "2.1.1"
+
+
+[profile.dev]
+# Rust debug is too slow.
+# For debug builds always builds with some optimization
+opt-level = "s"
+
+[profile.release]
+codegen-units    = 1     # LLVM can perform better optimizations using a single thread
+debug            = 2
+debug-assertions = false
+incremental      = false
+lto              = 'fat'
+opt-level        = 's'
+overflow-checks  = false

test1/build.rs

@@ -0,0 +1,52 @@
+fn main() {
+    linker_be_nice();
+    // make sure linkall.x is the last linker script (otherwise might cause problems with flip-link)
+    println!("cargo:rustc-link-arg=-Tlinkall.x");
+}
+
+fn linker_be_nice() {
+    let args: Vec<String> = std::env::args().collect();
+    if args.len() > 1 {
+        let kind = &args[1];
+        let what = &args[2];
+
+        match kind.as_str() {
+            "undefined-symbol" => match what.as_str() {
+                "_defmt_timestamp" => {
+                    eprintln!();
+                    eprintln!("💡 `defmt` not found - make sure `defmt.x` is added as a linker script and you have included `use defmt_rtt as _;`");
+                    eprintln!();
+                }
+                "_stack_start" => {
+                    eprintln!();
+                    eprintln!("💡 Is the linker script `linkall.x` missing?");
+                    eprintln!();
+                }
+                "esp_wifi_preempt_enable"
+                | "esp_wifi_preempt_yield_task"
+                | "esp_wifi_preempt_task_create" => {
+                    eprintln!();
+                    eprintln!("💡 `esp-wifi` has no scheduler enabled. Make sure you have the `builtin-scheduler` feature enabled, or that you provide an external scheduler.");
+                    eprintln!();
+                }
+                "embedded_test_linker_file_not_added_to_rustflags" => {
+                    eprintln!();
+                    eprintln!("💡 `embedded-test` not found - make sure `embedded-test.x` is added as a linker script for tests");
+                    eprintln!();
+                }
+                _ => (),
+            },
+            // we don't have anything helpful for "missing-lib" yet
+            _ => {
+                std::process::exit(1);
+            }
+        }
+
+        std::process::exit(0);
+    }
+
+    println!(
+        "cargo:rustc-link-arg=-Wl,--error-handling-script={}",
+        std::env::current_exe().unwrap().display()
+    );
+}

test1/rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "esp"

test1/src/bin/main.rs

@@ -0,0 +1,54 @@
+#![no_std]
+#![no_main]
+#![deny(
+    clippy::mem_forget,
+    reason = "mem::forget is generally not safe to do with esp_hal types, especially those \
+    holding buffers for the duration of a data transfer."
+)]
+
+use embassy_executor::Spawner;
+use embassy_time::{Duration, Timer};
+use esp_backtrace as _;
+use esp_hal::clock::CpuClock;
+use esp_hal::timer::timg::TimerGroup;
+use log::info;
+
+extern crate alloc;
+
+// This creates a default app-descriptor required by the esp-idf bootloader.
+// For more information see: <https://docs.espressif.com/projects/esp-idf/en/stable/esp32/api-reference/system/app_image_format.html#application-description>
+esp_bootloader_esp_idf::esp_app_desc!();
+
+#[esp_hal_embassy::main]
+async fn main(spawner: Spawner) {
+    // generator version: 0.5.0
+
+    esp_println::logger::init_logger_from_env();
+
+    let config = esp_hal::Config::default().with_cpu_clock(CpuClock::max());
+    let peripherals = esp_hal::init(config);
+
+    esp_alloc::heap_allocator!(size: 64 * 1024);
+
+    let timer0 = TimerGroup::new(peripherals.TIMG1);
+    esp_hal_embassy::init(timer0.timer0);
+
+    info!("Embassy initialized!");
+
+    let rng = esp_hal::rng::Rng::new(peripherals.RNG);
+    let timer1 = TimerGroup::new(peripherals.TIMG0);
+    let wifi_init =
+        esp_wifi::init(timer1.timer0, rng).expect("Failed to initialize WIFI/BLE controller");
+    let (mut _wifi_controller, _interfaces) = esp_wifi::wifi::new(&wifi_init, peripherals.WIFI)
+        .expect("Failed to initialize WIFI controller");
+
+    // TODO: Spawn some tasks
+    let _ = spawner;
+
+    loop {
+        info!("Hello world!");
+        Timer::after(Duration::from_secs(1)).await;
+    }
+
+    // for inspiration have a look at the examples at https://github.com/esp-rs/esp-hal/tree/esp-hal-v1.0.0-rc.0/examples/src/bin
+}

test1/src/lib.rs

@@ -0,0 +1 @@
+#![no_std]