feat: add embassy-boot/ dfu support

src/main.rs

@@ -230,6 +230,36 @@ async fn init_project(
         chip_or_board.clone()
     };
 
+    // Ask about embassy-boot (DFU) for RP2040-based chips only.
+    let mut embassy_boot = false;
+    let mut flash_size: u32 = 2 * 1024 * 1024; // default 2 MB
+    if chip_or_board == "rp2040" || chip_or_board == "pico_w" {
+        embassy_boot = Select::new(
+            "Use embassy-boot (DFU firmware update via USB)?",
+            vec!["No", "Yes"],
+        )
+        .prompt()?
+            == "Yes";
+        if embassy_boot {
+            flash_size = Select::new(
+                "Total flash size:",
+                vec!["2 MB", "4 MB", "8 MB", "16 MB"],
+            )
+            .with_help_message(
+                "When in doubt, use 2 MB. Smaller works on bigger flashes.",
+            )
+            .prompt()
+            .map(|s| match s {
+                "2 MB" => 2 * 1024 * 1024,
+                "4 MB" => 4 * 1024 * 1024,
+                "8 MB" => 8 * 1024 * 1024,
+                "16 MB" => 16 * 1024 * 1024,
+                _ => unreachable!(),
+            })?;
+        }
+    }
+
+    let target_dir_clone = target_dir.clone();
     let project_info = ProjectInfo {
         project_name,
         target_dir,
@@ -261,6 +291,123 @@ async fn init_project(
     // Post-process
     post_process(project_info)?;
 
+    // Apply embassy-boot customisations
+    if embassy_boot {
+        apply_embassy_boot(&target_dir_clone, flash_size)?;
+    }
+
+    Ok(())
+}
+
+/// Apply embassy-boot (DFU) template customisations to a generated project.
+fn apply_embassy_boot(
+    target_dir: &Path,
+    flash_size: u32,
+) -> Result<(), Box<dyn Error>> {
+    // ── memory.x ──────────────────────────────────────────────────────
+    // No BOOT2 region — the embassy-boot bootloader (e.g. bootymcbootface)
+    // provides it. The firmware starts at the ACTIVE slot (0x10007000).
+    let flash_len = flash_size / 4;
+    let flash_len_str = if flash_len >= 1024 * 1024 {
+        format!("{}M", flash_len / (1024 * 1024))
+    } else if flash_len % 1024 == 0 {
+        format!("{}K", flash_len / 1024)
+    } else {
+        flash_len.to_string()
+    };
+    let memory_x = format!(
+        "MEMORY {{\n\
+         \x20   FLASH : ORIGIN = 0x10007000, LENGTH = {}\n\
+         \x20   RAM   : ORIGIN = 0x20000000, LENGTH = 256K\n\
+         }}\n",
+        flash_len_str
+    );
+    fs::write(target_dir.join("memory.x"), memory_x)?;
+
+    // ── Cargo.toml ────────────────────────────────────────────────────
+    let cargo_path = target_dir.join("Cargo.toml");
+    let cargo = fs::read_to_string(&cargo_path)?;
+
+    // 1  rmk feature: "rp2040" → "dfu_rp"
+    let cargo = cargo.replace(
+        r#"features = ["rp2040"]"#,
+        r#"features = ["dfu_rp"]"#,
+    );
+
+    // 2  cortex-m-rt: add set-vtor
+    let cargo = cargo.replace(
+        "cortex-m-rt = \"0.7.5\"",
+        "cortex-m-rt = { version = \"0.7.5\", features = [\"set-vtor\"] }",
+    );
+
+    // 3  embassy-rp: add critical-section-impl feature
+    let cargo = cargo.replace(
+        r#"features = [
+    "rp2040",
+    "defmt",
+    "time-driver",
+]"#,
+        r#"features = [
+    "rp2040",
+    "defmt",
+    "time-driver",
+    "critical-section-impl",
+]"#,
+    );
+
+    // 4  Add portable-atomic (needed by embassy-boot-rp)
+    let cargo = if cargo.contains("portable-atomic") {
+        cargo
+    } else {
+        // Insert after the embassy-rp / embassy-executor block
+        cargo.replace(
+            "embassy-executor",
+            "portable-atomic = { version = \"1.11\", features = [\"critical-section\"] }\nembassy-executor",
+        )
+    };
+
+    // 6  embassy-rp: bump version to 0.10 (needed by embassy-boot-rp)
+    let cargo = cargo.replace(
+        "embassy-rp = { version = \"0.8\", features = [",
+        "embassy-rp = { version = \"0.10\", features = [",
+    );
+
+    // 7  Add embassy-usb-driver (needed by embassy-usb-dfu on RP2040)
+    let cargo = if cargo.contains("embassy-usb-driver") {
+        cargo
+    } else {
+        cargo.replace(
+            "panic-probe",
+            "embassy-usb-driver = \"=0.2.0\"\npanic-probe",
+        )
+    };
+
+    fs::write(&cargo_path, cargo)?;
+
+    // ── keyboard.toml ─────────────────────────────────────────────────
+    let kb_path = target_dir.join("keyboard.toml");
+    let mut kb = fs::read_to_string(&kb_path)?;
+    // ensure [storage] is present (needed by dfu_rp flash init)
+    if !kb.contains("[storage]") {
+        kb.push_str("\n[storage]\nenabled = true\n");
+    }
+    kb.push_str(
+        "\n\
+         [dfu]\n\
+         led = \"PIN_25\"\n",
+    );
+    fs::write(&kb_path, kb)?;
+
+    // ── build.rs – strip flip-link ────────────────────────────────────
+    let build_path = target_dir.join("build.rs");
+    if build_path.exists() {
+        let build = fs::read_to_string(&build_path)?;
+        // comment out any flip-link references
+        let build = build.replace("flip-link", "# flip-link");
+        fs::write(&build_path, build)?;
+    }
+
+    println!("✓ embassy-boot (DFU) template applied");
     Ok(())
 }