uart: refactor uart module to build async/await serial structure

.github/workflows/Cargo.yml

@@ -42,13 +42,13 @@ jobs:
       matrix:
         TARGET: [riscv64imac-unknown-none-elf]
         TOOLCHAIN: [nightly]
-        EXAMPLES: [gpio-demo, i2c-demo, jtag-demo, lz4d-demo, psram-demo, pwm-demo, 
-          sdcard-demo, sdcard-gpt-demo, spi-demo, uart-demo]
+        EXAMPLES: [gpio-demo, i2c-demo, jtag-demo, lz4d-demo, pwm-demo, 
+          sdcard-demo, sdcard-gpt-demo, spi-demo, uart-demo, uart-async-demo, uart-cli-demo]
     steps:
       - uses: actions/checkout@v4
       - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
           target: ${{ MATRIX.TARGET }}
           toolchain: ${{ MATRIX.TOOLCHAIN }}
       - name: Run build
-        run: cargo build --target ${{ MATRIX.TARGET }} --release -p ${{ MATRIX.EXAMPLES }}
+        run: cargo build --target ${{ MATRIX.TARGET }} --release -p ${{ MATRIX.EXAMPLES }}

Cargo.toml

@@ -15,6 +15,7 @@ members = [
     "examples/peripherals/pwm-demo",
     "examples/peripherals/spi-demo",
     "examples/peripherals/uart-demo",
+    "examples/peripherals/uart-async-demo",
     "examples/peripherals/uart-cli-demo",
     "examples/peripherals/sdcard-demo",
     "examples/peripherals/sdcard-gpt-demo",

bouffalo-hal/Cargo.toml

@@ -20,6 +20,8 @@ as-slice = "0.2.1"
 nb = "1.1.0"
 # For backward compatibility only. 
 embedded-hal-027 = { package = "embedded-hal", version = "0.2.7" }
+embedded-io-async = "0.6.1"
+atomic-waker = "1.1.2"
 
 [dev-dependencies]
 memoffset = "0.9.0"

bouffalo-hal/src/lib.rs

@@ -39,6 +39,7 @@ pub mod prelude {
     pub use embedded_hal::i2c::I2c as _;
     pub use embedded_hal::pwm::SetDutyCycle as _;
     pub use embedded_io::{Read as _, Write as _};
+    pub use embedded_io_async::{Read as _, Write as _};
 }
 
 /// Wrapper type for manipulations of a field in a register.