Add an option to not use embassy

Embassy is still set as a dependency on V2/V3 targets because it is used
for the USB support.
But on CH32V003, disabling embassy allows to save precious FLASH size.

.github/workflows/build.yml

@@ -34,6 +34,7 @@ jobs:
             ch32x035,
             ch641,
           ]
+        embassy: [true, false]
         include:
           - mcu_family: ch32l003
             target: riscv32imac-unknown-none-elf
@@ -60,7 +61,7 @@ jobs:
       - uses: cargo-generate/cargo-generate-action@latest
         with:
           name: ${{ env.PROJECT_NAME }}
-          arguments: "--define mcu_family=${{ matrix.mcu_family }}"
+          arguments: "--define mcu_family=${{ matrix.mcu_family }} --define embassy=${{ matrix.embassy }}"
       # we need to move the generated project to a temp folder, away from the template project
       # otherwise `cargo` runs would fail
       # see https://github.com/rust-lang/cargo/issues/9922

Cargo.toml

@@ -10,20 +10,27 @@ name = "{{ project-name }}"
 harness = false # do not use the built in cargo test harness -> resolve rust-analyzer errors
 
 [dependencies]
+{% if embassy_dep -%}
 ch32-hal = { git = "https://github.com/ch32-rs/ch32-hal.git", features = [
     "{{ mcu }}",
     "embassy",
+{%- else -%}
+ch32-hal = { git = "https://github.com/ch32-rs/ch32-hal.git", default-features = false, features = [
+    "{{ mcu }}",
+{%- endif %}
     "time-driver-tim2",
     "rt",
     "memory-x",
 ] }
+{% if embassy_dep -%}
 embassy-executor = { version = "0.6.1", features = [
     "integrated-timers",
     "arch-spin",
     "executor-thread",
     "task-arena-size-128", # or better use nightly, but fails on recent Rust versions
 ] }
 embassy-time = { version = "0.3.0" }
+{%- endif %}
 qingke-rt = "0.5.0"
 qingke = "0.5.0"
 embedded-hal = "1.0.0"

cargo-generate.toml

@@ -6,6 +6,12 @@ ignore = [".git", ".github", "README.md"]
 pre = ["pre-script.rhai"]
 post = ["post-script.rhai"]
 
+# Embassy option
+[placeholders.embassy]
+type = "bool"
+prompt = "Enable embassy (async) support?"
+default = true
+
 [placeholders.mcu_family]
 type = "string"
 prompt = "Which MCU family to target?"

pre-script.rhai

@@ -12,6 +12,7 @@ let targets = #{
     ch641: "riscv32ec-unknown-none-elf",
 };
 
+let embassy = variable::get("embassy");
 let mcu_family = variable::get("mcu_family");
 let target = targets.get(mcu_family);
 variable::set("target", `${target}`);
@@ -22,3 +23,14 @@ if mcu_family == "ch641" {
 } else if mcu_family == "ch32x033" {
     variable::set("mcu", "ch32x033f8p6");
 }
+
+if embassy {
+    variable::set("embassy_dep", true);
+} else {
+    // Even if embassy not selected, add embassy dependency for the V2/V3 because USB support depends on Embassy
+    if mcu_family == "ch32v203" || mcu_family == "ch32v208" || mcu_family == "ch32v303" || mcu_family == "ch32v305" || mcu_family == "ch32v307" {
+        variable::set("embassy_dep", true);
+    } else {
+        variable::set("embassy_dep", false);
+    }
+}

src/main.rs

@@ -2,6 +2,7 @@
 #![no_main]
 #![feature(type_alias_impl_trait)]
 
+{% if embassy -%}
 use embassy_executor::Spawner;
 use embassy_time::Timer;
 use ch32_hal::gpio::{AnyPin, Level, Output, Pin};
@@ -29,9 +30,28 @@ async fn main(spawner: Spawner) -> ! {
 
     // Adjust the LED GPIO according to your board
     spawner.spawn(blink(p.PA0.degrade(), 1000)).unwrap();
-
     loop {
         Timer::after_millis(1000).await;
         println!("tick");
     }
 }
+{%- else -%}
+use hal::delay::Delay;
+use hal::gpio::{Level, Output};
+use {ch32_hal as hal, panic_halt as _};
+
+#[qingke_rt::entry]
+fn main() -> ! {
+    hal::debug::SDIPrint::enable();
+    let p = hal::init(hal::Config::default());
+    let mut delay = Delay;
+
+    // Adjust the LED GPIO according to your board
+    let mut led = Output::new(p.PA0, Level::Low, Default::default());
+    loop {
+        led.toggle();
+        delay.delay_ms(1000);
+        hal::println!("toggle!");
+    }
+}
+{%- endif %}