Merge #709

709: embassy-usb stm32 r=Dirbaio a=Dirbaio

TODO

- [x] Add cfgs for EP_COUNT, EP_MEMORY_ADDR. -- ended up doing it in stm32-data
- [x] Auto-enable PWR USV in stm32l5,
- [x] Auto-enable PWR on other families that need it -- didn't find any
- [ ] ~~Assert at runtime that RCC has valid 48Mhz clock?~~ -- won't do it yet, too messy without rcc cleanup
- [x] Tested on STM32L5
- [x] Tested on STM32F303ZE
- [x] Tested on STM32F103c8
- [x] Fix duplicated irqs on STM32F303 in stm32data, remove workaround in embassy-stm32
- [x] Test HID example
- [x] Test NCM example


Co-authored-by: Dario Nieuwenhuis <dirbaio@dirbaio.net>

embassy-stm32/Cargo.toml

@@ -37,6 +37,7 @@ embassy = { version = "0.1.0", path = "../embassy" }
 embassy-macros = { version = "0.1.0", path = "../embassy-macros", features = ["stm32"] }
 embassy-hal-common = {version = "0.1.0", path = "../embassy-hal-common" }
 embassy-net = { version = "0.1.0", path = "../embassy-net", optional = true }
+embassy-usb = {version = "0.1.0", path = "../embassy-usb", optional = true }
 
 embedded-hal-02 = { package = "embedded-hal", version = "0.2.6", features = ["unproven"] }
 embedded-hal-1 = { package = "embedded-hal", version = "1.0.0-alpha.8", optional = true}
@@ -71,7 +72,7 @@ quote = "1.0.15"
 stm32-metapac = { version = "0.1.0", path = "../stm32-metapac", default-features = false, features = ["metadata"]}
 
 [features]
-defmt = ["dep:defmt", "embassy/defmt", "embedded-io?/defmt" ]
+defmt = ["dep:defmt", "embassy/defmt", "embedded-io?/defmt", "embassy-usb?/defmt"]
 sdmmc-rs = ["embedded-sdmmc"]
 net = ["embassy-net" ]
 memory-x = ["stm32-metapac/memory-x"]
@@ -90,7 +91,7 @@ time-driver-tim12 = ["_time-driver"]
 time-driver-tim15 = ["_time-driver"]
 
 # Enable nightly-only features
-nightly = ["embassy/nightly", "embedded-hal-1", "embedded-hal-async", "embedded-storage-async", "dep:embedded-io"]
+nightly = ["embassy/nightly", "embedded-hal-1", "embedded-hal-async", "embedded-storage-async", "dep:embedded-io", "dep:embassy-usb"]
 
 # Reexport stm32-metapac at `embassy_stm32::pac`.
 # This is unstable because semver-minor (non-breaking) releases of embassy-stm32 may major-bump (breaking) the stm32-metapac version.

embassy-stm32/build.rs

@@ -279,6 +279,8 @@ fn main() {
         (("dcmi", "HSYNC"), quote!(crate::dcmi::HSyncPin)),
         (("dcmi", "VSYNC"), quote!(crate::dcmi::VSyncPin)),
         (("dcmi", "PIXCLK"), quote!(crate::dcmi::PixClkPin)),
+        (("usb", "DP"), quote!(crate::usb::DpPin)),
+        (("usb", "DM"), quote!(crate::usb::DmPin)),
         (("otgfs", "DP"), quote!(crate::usb_otg::DpPin)),
         (("otgfs", "DM"), quote!(crate::usb_otg::DmPin)),
         (("otghs", "DP"), quote!(crate::usb_otg::DpPin)),

embassy-stm32/src/lib.rs

@@ -63,6 +63,8 @@ pub mod sdmmc;
 pub mod spi;
 #[cfg(usart)]
 pub mod usart;
+#[cfg(usb)]
+pub mod usb;
 #[cfg(any(otgfs, otghs))]
 pub mod usb_otg;
 

embassy-stm32/src/usb/mod.rs

@@ -0,0 +1,36 @@
+use embassy::interrupt::Interrupt;
+
+use crate::rcc::RccPeripheral;
+
+#[cfg(feature = "nightly")]
+mod usb;
+#[cfg(feature = "nightly")]
+pub use usb::*;
+
+pub(crate) mod sealed {
+    pub trait Instance {
+        fn regs() -> crate::pac::usb::Usb;
+    }
+}
+
+pub trait Instance: sealed::Instance + RccPeripheral + 'static {
+    type Interrupt: Interrupt;
+}
+
+// Internal PHY pins
+pin_trait!(DpPin, Instance);
+pin_trait!(DmPin, Instance);
+
+foreach_interrupt!(
+    ($inst:ident, usb, $block:ident, LP, $irq:ident) => {
+        impl sealed::Instance for crate::peripherals::$inst {
+            fn regs() -> crate::pac::usb::Usb {
+                crate::pac::$inst
+            }
+        }
+
+        impl Instance for crate::peripherals::$inst {
+            type Interrupt = crate::interrupt::$irq;
+        }
+    };
+);

examples/stm32f1/Cargo.toml

@@ -8,6 +8,8 @@ resolver = "2"
 [dependencies]
 embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-timestamp-uptime", "time-tick-32768hz"] }
 embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f103c8", "unstable-pac", "memory-x", "time-driver-any"]  }
+embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
+embassy-usb-serial = { version = "0.1.0", path = "../../embassy-usb-serial", features = ["defmt"] }
 
 defmt = "0.3"
 defmt-rtt = "0.3"

examples/stm32f1/src/bin/usb_serial.rs

@@ -0,0 +1,117 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::panic;
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::executor::Spawner;
+use embassy::time::Duration;
+use embassy::time::Timer;
+use embassy_stm32::gpio::Level;
+use embassy_stm32::gpio::Output;
+use embassy_stm32::gpio::Speed;
+use embassy_stm32::interrupt;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::usb::{Driver, Instance};
+use embassy_stm32::{Config, Peripherals};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::Builder;
+use embassy_usb_serial::{CdcAcmClass, State};
+use futures::future::join;
+use panic_probe as _;
+
+fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.hse = Some(Hertz(8_000_000));
+    config.rcc.sys_ck = Some(Hertz(48_000_000));
+    config.rcc.pclk1 = Some(Hertz(24_000_000));
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, mut p: Peripherals) {
+    info!("Hello World!");
+
+    {
+        // BluePill board has a pull-up resistor on the D+ line.
+        // Pull the D+ pin down to send a RESET condition to the USB bus.
+        // This forced reset is needed only for development, without it host
+        // will not reset your device when you upload new firmware.
+        let _dp = Output::new(&mut p.PA12, Level::Low, Speed::Low);
+        Timer::after(Duration::from_millis(10)).await;
+    }
+
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USB_LP_CAN1_RX0);
+    let driver = Driver::new(p.USB, irq, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    //config.max_packet_size_0 = 64;
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut device_descriptor = [0; 256];
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 7];
+
+    let mut state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut control_buf,
+        None,
+    );
+
+    // Create classes on the builder.
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            info!("Connected");
+            let _ = echo(&mut class).await;
+            info!("Disconnected");
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, echo_fut).await;
+}
+
+struct Disconnected {}
+
+impl From<EndpointError> for Disconnected {
+    fn from(val: EndpointError) -> Self {
+        match val {
+            EndpointError::BufferOverflow => panic!("Buffer overflow"),
+            EndpointError::Disabled => Disconnected {},
+        }
+    }
+}
+
+async fn echo<'d, T: Instance + 'd>(
+    class: &mut CdcAcmClass<'d, Driver<'d, T>>,
+) -> Result<(), Disconnected> {
+    let mut buf = [0; 64];
+    loop {
+        let n = class.read_packet(&mut buf).await?;
+        let data = &buf[..n];
+        info!("data: {:x}", data);
+        class.write_packet(data).await?;
+    }
+}

examples/stm32f3/.cargo/config.toml

@@ -1,6 +1,6 @@
 [target.'cfg(all(target_arch = "arm", target_os = "none"))']
 # replace STM32F429ZITx with your chip as listed in `probe-run --list-chips`
-runner = "probe-run --chip STM32F303VCTx"
+runner = "probe-run --chip STM32F303ZETx"
 
 [build]
 target = "thumbv7em-none-eabihf"

examples/stm32f3/Cargo.toml

@@ -7,7 +7,10 @@ resolver = "2"
 
 [dependencies]
 embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-timestamp-uptime", "time-tick-32768hz"] }
-embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f303vc", "unstable-pac", "memory-x", "time-driver-any", "exti"]  }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "stm32f303ze", "unstable-pac", "memory-x", "time-driver-any", "exti"]  }
+embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
+embassy-usb-serial = { version = "0.1.0", path = "../../embassy-usb-serial", features = ["defmt"] }
+embassy-usb-hid = { version = "0.1.0", path = "../../embassy-usb-hid", features = ["defmt"] }
 
 defmt = "0.3"
 defmt-rtt = "0.3"

examples/stm32f3/src/bin/usb_serial.rs

@@ -0,0 +1,116 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::panic;
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::executor::Spawner;
+use embassy::time::Duration;
+use embassy::time::Timer;
+use embassy_stm32::gpio::Level;
+use embassy_stm32::gpio::Output;
+use embassy_stm32::gpio::Speed;
+use embassy_stm32::interrupt;
+use embassy_stm32::time::U32Ext;
+use embassy_stm32::usb::{Driver, Instance};
+use embassy_stm32::{Config, Peripherals};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::Builder;
+use embassy_usb_serial::{CdcAcmClass, State};
+use futures::future::join;
+use panic_probe as _;
+
+fn config() -> Config {
+    let mut config = Config::default();
+
+    config.rcc.hse = Some(8.mhz().into());
+    config.rcc.sysclk = Some(48.mhz().into());
+    config.rcc.pclk1 = Some(24.mhz().into());
+    config.rcc.pclk2 = Some(24.mhz().into());
+    config.rcc.pll48 = true;
+
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    // Needed for nucleo-stm32f303ze
+    let mut dp_pullup = Output::new(p.PG6, Level::Low, Speed::Medium);
+    Timer::after(Duration::from_millis(10)).await;
+    dp_pullup.set_high();
+
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USB_LP_CAN_RX0);
+    let driver = Driver::new(p.USB, irq, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let config = embassy_usb::Config::new(0xc0de, 0xcafe);
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut device_descriptor = [0; 256];
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 7];
+
+    let mut state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut control_buf,
+        None,
+    );
+
+    // Create classes on the builder.
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            info!("Connected");
+            let _ = echo(&mut class).await;
+            info!("Disconnected");
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, echo_fut).await;
+}
+
+struct Disconnected {}
+
+impl From<EndpointError> for Disconnected {
+    fn from(val: EndpointError) -> Self {
+        match val {
+            EndpointError::BufferOverflow => panic!("Buffer overflow"),
+            EndpointError::Disabled => Disconnected {},
+        }
+    }
+}
+
+async fn echo<'d, T: Instance + 'd>(
+    class: &mut CdcAcmClass<'d, Driver<'d, T>>,
+) -> Result<(), Disconnected> {
+    let mut buf = [0; 64];
+    loop {
+        let n = class.read_packet(&mut buf).await?;
+        let data = &buf[..n];
+        info!("data: {:x}", data);
+        class.write_packet(data).await?;
+    }
+}

examples/stm32l5/.cargo/config.toml

@@ -0,0 +1,6 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# replace STM32F429ZITx with your chip as listed in `probe-run --list-chips`
+runner = "probe-run --chip STM32L552ZETxQ"
+
+[build]
+target = "thumbv8m.main-none-eabihf"

examples/stm32l5/Cargo.toml

@@ -0,0 +1,30 @@
+[package]
+authors = ["Dario Nieuwenhuis <dirbaio@dirbaio.net>"]
+edition = "2018"
+name = "embassy-stm32l5-examples"
+version = "0.1.0"
+resolver = "2"
+
+[features]
+
+[dependencies]
+embassy = { version = "0.1.0", path = "../../embassy", features = ["defmt", "defmt-timestamp-uptime", "time-tick-32768hz"] }
+embassy-stm32 = { version = "0.1.0", path = "../../embassy-stm32", features = ["nightly", "defmt", "unstable-pac", "stm32l552ze", "time-driver-any", "exti", "unstable-traits", "memory-x"]  }
+embassy-usb = { version = "0.1.0", path = "../../embassy-usb", features = ["defmt"] }
+embassy-usb-serial = { version = "0.1.0", path = "../../embassy-usb-serial", features = ["defmt"] }
+embassy-usb-hid = { version = "0.1.0", path = "../../embassy-usb-hid", features = ["defmt"] }
+embassy-usb-ncm = { version = "0.1.0", path = "../../embassy-usb-ncm", features = ["defmt"] }
+embassy-net = { version = "0.1.0", path = "../../embassy-net", features = ["defmt", "tcp", "dhcpv4", "medium-ethernet", "pool-16"] }
+usbd-hid = "0.5.2"
+
+defmt = "0.3"
+defmt-rtt = "0.3"
+panic-probe = { version = "0.3", features = ["print-defmt"] }
+
+cortex-m = "0.7.3"
+cortex-m-rt = "0.7.0"
+embedded-hal = "0.2.6"
+futures = { version = "0.3.17", default-features = false, features = ["async-await"] }
+heapless = { version = "0.7.5", default-features = false }
+rand_core = { version = "0.6.3", default-features = false }
+embedded-io = { version = "0.3.0", features = ["async"] }

examples/stm32l5/build.rs

@@ -0,0 +1,5 @@
+fn main() {
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink.x");
+    println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+}

examples/stm32l5/src/bin/button_exti.rs

@@ -0,0 +1,28 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::executor::Spawner;
+use embassy_stm32::exti::ExtiInput;
+use embassy_stm32::gpio::{Input, Pull};
+use embassy_stm32::Peripherals;
+use panic_probe as _;
+
+#[embassy::main]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let button = Input::new(p.PC13, Pull::Down);
+    let mut button = ExtiInput::new(button, p.EXTI13);
+
+    info!("Press the USER button...");
+
+    loop {
+        button.wait_for_falling_edge().await;
+        info!("Pressed!");
+        button.wait_for_rising_edge().await;
+        info!("Released!");
+    }
+}

examples/stm32l5/src/bin/rng.rs

@@ -0,0 +1,34 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::executor::Spawner;
+use embassy_stm32::rcc::{ClockSrc, PLLClkDiv, PLLMul, PLLSource, PLLSrcDiv};
+use embassy_stm32::rng::Rng;
+use embassy_stm32::{Config, Peripherals};
+use panic_probe as _;
+
+fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.mux = ClockSrc::PLL(
+        PLLSource::HSI16,
+        PLLClkDiv::Div2,
+        PLLSrcDiv::Div1,
+        PLLMul::Mul8,
+        Some(PLLClkDiv::Div2),
+    );
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    let mut rng = Rng::new(p.RNG);
+
+    let mut buf = [0u8; 16];
+    unwrap!(rng.async_fill_bytes(&mut buf).await);
+    info!("random bytes: {:02x}", buf);
+}

examples/stm32l5/src/bin/usb_ethernet.rs

@@ -0,0 +1,290 @@
+#![no_std]
+#![no_main]
+#![feature(generic_associated_types)]
+#![feature(type_alias_impl_trait)]
+
+use core::sync::atomic::{AtomicBool, Ordering};
+use core::task::Waker;
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::blocking_mutex::raw::ThreadModeRawMutex;
+use embassy::channel::Channel;
+use embassy::executor::Spawner;
+use embassy::util::Forever;
+use embassy_net::tcp::TcpSocket;
+use embassy_net::{PacketBox, PacketBoxExt, PacketBuf, Stack, StackResources};
+use embassy_stm32::interrupt;
+use embassy_stm32::rcc::*;
+use embassy_stm32::rng::Rng;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::usb::Driver;
+use embassy_stm32::{Config, Peripherals};
+use embassy_usb::{Builder, UsbDevice};
+use embassy_usb_ncm::{CdcNcmClass, Receiver, Sender, State};
+use panic_probe as _;
+
+use defmt_rtt as _;
+use embedded_io::asynch::{Read, Write};
+// global logger
+use panic_probe as _;
+use rand_core::RngCore;
+
+type MyDriver = Driver<'static, embassy_stm32::peripherals::USB>;
+
+macro_rules! forever {
+    ($val:expr) => {{
+        type T = impl Sized;
+        static FOREVER: Forever<T> = Forever::new();
+        FOREVER.put_with(move || $val)
+    }};
+}
+
+#[embassy::task]
+async fn usb_task(mut device: UsbDevice<'static, MyDriver>) -> ! {
+    device.run().await
+}
+
+#[embassy::task]
+async fn usb_ncm_rx_task(mut class: Receiver<'static, MyDriver>) {
+    loop {
+        warn!("WAITING for connection");
+        LINK_UP.store(false, Ordering::Relaxed);
+
+        class.wait_connection().await.unwrap();
+
+        warn!("Connected");
+        LINK_UP.store(true, Ordering::Relaxed);
+
+        loop {
+            let mut p = unwrap!(PacketBox::new(embassy_net::Packet::new()));
+            let n = match class.read_packet(&mut p[..]).await {
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("error reading packet: {:?}", e);
+                    break;
+                }
+            };
+
+            let buf = p.slice(0..n);
+            if RX_CHANNEL.try_send(buf).is_err() {
+                warn!("Failed pushing rx'd packet to channel.");
+            }
+        }
+    }
+}
+
+#[embassy::task]
+async fn usb_ncm_tx_task(mut class: Sender<'static, MyDriver>) {
+    loop {
+        let pkt = TX_CHANNEL.recv().await;
+        if let Err(e) = class.write_packet(&pkt[..]).await {
+            warn!("Failed to TX packet: {:?}", e);
+        }
+    }
+}
+
+#[embassy::task]
+async fn net_task(stack: &'static Stack<Device>) -> ! {
+    stack.run().await
+}
+
+fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.mux = ClockSrc::HSE(Hertz(16_000_000));
+
+    config.rcc.mux = ClockSrc::PLL(
+        PLLSource::HSI16,
+        PLLClkDiv::Div2,
+        PLLSrcDiv::Div1,
+        PLLMul::Mul10,
+        None,
+    );
+    config.rcc.hsi48 = true;
+
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(spawner: Spawner, p: Peripherals) {
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USB_FS);
+    let driver = Driver::new(p.USB, irq, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("USB-Ethernet example");
+    config.serial_number = Some("12345678");
+    config.max_power = 100;
+    config.max_packet_size_0 = 64;
+
+    // Required for Windows support.
+    config.composite_with_iads = true;
+    config.device_class = 0xEF;
+    config.device_sub_class = 0x02;
+    config.device_protocol = 0x01;
+
+    struct Resources {
+        device_descriptor: [u8; 256],
+        config_descriptor: [u8; 256],
+        bos_descriptor: [u8; 256],
+        control_buf: [u8; 128],
+        serial_state: State<'static>,
+    }
+    let res: &mut Resources = forever!(Resources {
+        device_descriptor: [0; 256],
+        config_descriptor: [0; 256],
+        bos_descriptor: [0; 256],
+        control_buf: [0; 128],
+        serial_state: State::new(),
+    });
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut res.device_descriptor,
+        &mut res.config_descriptor,
+        &mut res.bos_descriptor,
+        &mut res.control_buf,
+        None,
+    );
+
+    // WARNINGS for Android ethernet tethering:
+    // - On Pixel 4a, it refused to work on Android 11, worked on Android 12.
+    // - if the host's MAC address has the "locally-administered" bit set (bit 1 of first byte),
+    //   it doesn't work! The "Ethernet tethering" option in settings doesn't get enabled.
+    //   This is due to regex spaghetti: https://android.googlesource.com/platform/frameworks/base/+/refs/tags/android-mainline-12.0.0_r84/core/res/res/values/config.xml#417
+    //   and this nonsense in the linux kernel: https://github.com/torvalds/linux/blob/c00c5e1d157bec0ef0b0b59aa5482eb8dc7e8e49/drivers/net/usb/usbnet.c#L1751-L1757
+
+    // Our MAC addr.
+    let our_mac_addr = [0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC];
+    // Host's MAC addr. This is the MAC the host "thinks" its USB-to-ethernet adapter has.
+    let host_mac_addr = [0x88, 0x88, 0x88, 0x88, 0x88, 0x88];
+
+    // Create classes on the builder.
+    let class = CdcNcmClass::new(&mut builder, &mut res.serial_state, host_mac_addr, 64);
+
+    // Build the builder.
+    let usb = builder.build();
+
+    unwrap!(spawner.spawn(usb_task(usb)));
+
+    let (tx, rx) = class.split();
+    unwrap!(spawner.spawn(usb_ncm_rx_task(rx)));
+    unwrap!(spawner.spawn(usb_ncm_tx_task(tx)));
+
+    let config = embassy_net::ConfigStrategy::Dhcp;
+    //let config = embassy_net::ConfigStrategy::Static(embassy_net::Config {
+    //    address: Ipv4Cidr::new(Ipv4Address::new(10, 42, 0, 61), 24),
+    //    dns_servers: Vec::new(),
+    //    gateway: Some(Ipv4Address::new(10, 42, 0, 1)),
+    //});
+
+    // Generate random seed
+    let mut rng = Rng::new(p.RNG);
+    let seed = rng.next_u64();
+
+    // Init network stack
+    let device = Device {
+        mac_addr: our_mac_addr,
+    };
+    let stack = &*forever!(Stack::new(
+        device,
+        config,
+        forever!(StackResources::<1, 2, 8>::new()),
+        seed
+    ));
+
+    unwrap!(spawner.spawn(net_task(stack)));
+
+    // And now we can use it!
+
+    let mut rx_buffer = [0; 4096];
+    let mut tx_buffer = [0; 4096];
+    let mut buf = [0; 4096];
+
+    loop {
+        let mut socket = TcpSocket::new(stack, &mut rx_buffer, &mut tx_buffer);
+        socket.set_timeout(Some(embassy_net::SmolDuration::from_secs(10)));
+
+        info!("Listening on TCP:1234...");
+        if let Err(e) = socket.accept(1234).await {
+            warn!("accept error: {:?}", e);
+            continue;
+        }
+
+        info!("Received connection from {:?}", socket.remote_endpoint());
+
+        loop {
+            let n = match socket.read(&mut buf).await {
+                Ok(0) => {
+                    warn!("read EOF");
+                    break;
+                }
+                Ok(n) => n,
+                Err(e) => {
+                    warn!("read error: {:?}", e);
+                    break;
+                }
+            };
+
+            info!("rxd {:02x}", &buf[..n]);
+
+            match socket.write_all(&buf[..n]).await {
+                Ok(()) => {}
+                Err(e) => {
+                    warn!("write error: {:?}", e);
+                    break;
+                }
+            };
+        }
+    }
+}
+
+static TX_CHANNEL: Channel<ThreadModeRawMutex, PacketBuf, 8> = Channel::new();
+static RX_CHANNEL: Channel<ThreadModeRawMutex, PacketBuf, 8> = Channel::new();
+static LINK_UP: AtomicBool = AtomicBool::new(false);
+
+struct Device {
+    mac_addr: [u8; 6],
+}
+
+impl embassy_net::Device for Device {
+    fn register_waker(&mut self, waker: &Waker) {
+        // loopy loopy wakey wakey
+        waker.wake_by_ref()
+    }
+
+    fn link_state(&mut self) -> embassy_net::LinkState {
+        match LINK_UP.load(Ordering::Relaxed) {
+            true => embassy_net::LinkState::Up,
+            false => embassy_net::LinkState::Down,
+        }
+    }
+
+    fn capabilities(&self) -> embassy_net::DeviceCapabilities {
+        let mut caps = embassy_net::DeviceCapabilities::default();
+        caps.max_transmission_unit = 1514; // 1500 IP + 14 ethernet header
+        caps.medium = embassy_net::Medium::Ethernet;
+        caps
+    }
+
+    fn is_transmit_ready(&mut self) -> bool {
+        true
+    }
+
+    fn transmit(&mut self, pkt: PacketBuf) {
+        if TX_CHANNEL.try_send(pkt).is_err() {
+            warn!("TX failed")
+        }
+    }
+
+    fn receive<'a>(&mut self) -> Option<PacketBuf> {
+        RX_CHANNEL.try_recv().ok()
+    }
+
+    fn ethernet_address(&self) -> [u8; 6] {
+        self.mac_addr
+    }
+}

examples/stm32l5/src/bin/usb_hid_mouse.rs

@@ -0,0 +1,136 @@
+#![no_std]
+#![no_main]
+#![feature(generic_associated_types)]
+#![feature(type_alias_impl_trait)]
+
+use defmt::*;
+use embassy::executor::Spawner;
+use embassy::time::{Duration, Timer};
+use embassy_stm32::interrupt;
+use embassy_stm32::rcc::*;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::usb::Driver;
+use embassy_stm32::{Config, Peripherals};
+use embassy_usb::control::OutResponse;
+use embassy_usb::Builder;
+use embassy_usb_hid::{HidWriter, ReportId, RequestHandler, State};
+use futures::future::join;
+use usbd_hid::descriptor::{MouseReport, SerializedDescriptor};
+
+use defmt_rtt as _; // global logger
+use panic_probe as _;
+
+fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.mux = ClockSrc::HSE(Hertz(16_000_000));
+
+    config.rcc.mux = ClockSrc::PLL(
+        PLLSource::HSI16,
+        PLLClkDiv::Div2,
+        PLLSrcDiv::Div1,
+        PLLMul::Mul10,
+        None,
+    );
+    config.rcc.hsi48 = true;
+
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USB_FS);
+    let driver = Driver::new(p.USB, irq, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("HID mouse example");
+    config.serial_number = Some("12345678");
+    config.max_power = 100;
+    config.max_packet_size_0 = 64;
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut device_descriptor = [0; 256];
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 64];
+    let request_handler = MyRequestHandler {};
+
+    let mut state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut control_buf,
+        None,
+    );
+
+    // Create classes on the builder.
+    let config = embassy_usb_hid::Config {
+        report_descriptor: MouseReport::desc(),
+        request_handler: Some(&request_handler),
+        poll_ms: 60,
+        max_packet_size: 8,
+    };
+
+    let mut writer = HidWriter::<_, 5>::new(&mut builder, &mut state, config);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let hid_fut = async {
+        let mut y: i8 = 5;
+        loop {
+            Timer::after(Duration::from_millis(500)).await;
+
+            y = -y;
+            let report = MouseReport {
+                buttons: 0,
+                x: 0,
+                y,
+                wheel: 0,
+                pan: 0,
+            };
+            match writer.write_serialize(&report).await {
+                Ok(()) => {}
+                Err(e) => warn!("Failed to send report: {:?}", e),
+            }
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, hid_fut).await;
+}
+
+struct MyRequestHandler {}
+
+impl RequestHandler for MyRequestHandler {
+    fn get_report(&self, id: ReportId, _buf: &mut [u8]) -> Option<usize> {
+        info!("Get report for {:?}", id);
+        None
+    }
+
+    fn set_report(&self, id: ReportId, data: &[u8]) -> OutResponse {
+        info!("Set report for {:?}: {=[u8]}", id, data);
+        OutResponse::Accepted
+    }
+
+    fn set_idle(&self, id: Option<ReportId>, dur: Duration) {
+        info!("Set idle rate for {:?} to {:?}", id, dur);
+    }
+
+    fn get_idle(&self, id: Option<ReportId>) -> Option<Duration> {
+        info!("Get idle rate for {:?}", id);
+        None
+    }
+}

examples/stm32l5/src/bin/usb_serial.rs

@@ -0,0 +1,112 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use defmt::panic;
+use defmt::*;
+use defmt_rtt as _; // global logger
+use embassy::executor::Spawner;
+use embassy_stm32::interrupt;
+use embassy_stm32::rcc::*;
+use embassy_stm32::time::Hertz;
+use embassy_stm32::usb::{Driver, Instance};
+use embassy_stm32::{Config, Peripherals};
+use embassy_usb::driver::EndpointError;
+use embassy_usb::Builder;
+use embassy_usb_serial::{CdcAcmClass, State};
+use futures::future::join;
+use panic_probe as _;
+
+fn config() -> Config {
+    let mut config = Config::default();
+    config.rcc.mux = ClockSrc::HSE(Hertz(16_000_000));
+
+    config.rcc.mux = ClockSrc::PLL(
+        PLLSource::HSI16,
+        PLLClkDiv::Div2,
+        PLLSrcDiv::Div1,
+        PLLMul::Mul10,
+        None,
+    );
+    config.rcc.hsi48 = true;
+
+    config
+}
+
+#[embassy::main(config = "config()")]
+async fn main(_spawner: Spawner, p: Peripherals) {
+    info!("Hello World!");
+
+    // Create the driver, from the HAL.
+    let irq = interrupt::take!(USB_FS);
+    let driver = Driver::new(p.USB, irq, p.PA12, p.PA11);
+
+    // Create embassy-usb Config
+    let config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    //config.max_packet_size_0 = 64;
+
+    // Create embassy-usb DeviceBuilder using the driver and config.
+    // It needs some buffers for building the descriptors.
+    let mut device_descriptor = [0; 256];
+    let mut config_descriptor = [0; 256];
+    let mut bos_descriptor = [0; 256];
+    let mut control_buf = [0; 7];
+
+    let mut state = State::new();
+
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut control_buf,
+        None,
+    );
+
+    // Create classes on the builder.
+    let mut class = CdcAcmClass::new(&mut builder, &mut state, 64);
+
+    // Build the builder.
+    let mut usb = builder.build();
+
+    // Run the USB device.
+    let usb_fut = usb.run();
+
+    // Do stuff with the class!
+    let echo_fut = async {
+        loop {
+            class.wait_connection().await;
+            info!("Connected");
+            let _ = echo(&mut class).await;
+            info!("Disconnected");
+        }
+    };
+
+    // Run everything concurrently.
+    // If we had made everything `'static` above instead, we could do this using separate tasks instead.
+    join(usb_fut, echo_fut).await;
+}
+
+struct Disconnected {}
+
+impl From<EndpointError> for Disconnected {
+    fn from(val: EndpointError) -> Self {
+        match val {
+            EndpointError::BufferOverflow => panic!("Buffer overflow"),
+            EndpointError::Disabled => Disconnected {},
+        }
+    }
+}
+
+async fn echo<'d, T: Instance + 'd>(
+    class: &mut CdcAcmClass<'d, Driver<'d, T>>,
+) -> Result<(), Disconnected> {
+    let mut buf = [0; 64];
+    loop {
+        let n = class.read_packet(&mut buf).await?;
+        let data = &buf[..n];
+        info!("data: {:x}", data);
+        class.write_packet(data).await?;
+    }
+}