Merge pull request #2284 from Redrield/feature/embassy-usb-dfu

Add embassy-usb-dfu crate, with related modifications to embassy-boot

23 files changed, 1219 insertions, 7 deletions

diff --git a/ci.sh b/ci.sh
index 8a5e206d2..83c05d1b9 100755
--- a/ci.sh
+++ b/ci.sh
@@ -173,10 +173,12 @@ cargo batch  \
     --- build --release --manifest-path examples/boot/application/stm32l1/Cargo.toml --target thumbv7m-none-eabi --features skip-include --out-dir out/examples/boot/stm32l1 \
     --- build --release --manifest-path examples/boot/application/stm32l4/Cargo.toml --target thumbv7em-none-eabi --features skip-include --out-dir out/examples/boot/stm32l4 \
     --- build --release --manifest-path examples/boot/application/stm32wl/Cargo.toml --target thumbv7em-none-eabihf --features skip-include --out-dir out/examples/boot/stm32wl \
+    --- build --release --manifest-path examples/boot/application/stm32wb-dfu/Cargo.toml --target thumbv7em-none-eabihf --out-dir out/examples/boot/stm32wb-dfu \
     --- build --release --manifest-path examples/boot/bootloader/nrf/Cargo.toml --target thumbv7em-none-eabi --features embassy-nrf/nrf52840 \
     --- build --release --manifest-path examples/boot/bootloader/nrf/Cargo.toml --target thumbv8m.main-none-eabihf --features embassy-nrf/nrf9160-ns \
     --- build --release --manifest-path examples/boot/bootloader/rp/Cargo.toml --target thumbv6m-none-eabi \
     --- build --release --manifest-path examples/boot/bootloader/stm32/Cargo.toml --target thumbv7em-none-eabi --features embassy-stm32/stm32wl55jc-cm4 \
+    --- build --release --manifest-path examples/boot/bootloader/stm32wb-dfu/Cargo.toml --target thumbv7em-none-eabihf \
     --- build --release --manifest-path examples/wasm/Cargo.toml --target wasm32-unknown-unknown --out-dir out/examples/wasm \
     --- build --release --manifest-path tests/stm32/Cargo.toml --target thumbv7m-none-eabi --features stm32f103c8 --out-dir out/tests/stm32f103c8 \
     --- build --release --manifest-path tests/stm32/Cargo.toml --target thumbv7em-none-eabi --features stm32f429zi --out-dir out/tests/stm32f429zi \
diff --git a/embassy-boot/boot/src/boot_loader.rs b/embassy-boot/boot/src/boot_loader.rs
index 65b12dc5f..e568001bc 100644
--- a/embassy-boot/boot/src/boot_loader.rs
+++ b/embassy-boot/boot/src/boot_loader.rs
@@ -5,7 +5,7 @@ use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use embassy_sync::blocking_mutex::Mutex;
 use embedded_storage::nor_flash::{NorFlash, NorFlashError, NorFlashErrorKind};
 
-use crate::{State, BOOT_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
+use crate::{State, BOOT_MAGIC, DFU_DETACH_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
 
 /// Errors returned by bootloader
 #[derive(PartialEq, Eq, Debug)]
@@ -371,6 +371,8 @@ impl<ACTIVE: NorFlash, DFU: NorFlash, STATE: NorFlash> BootLoader<ACTIVE, DFU, S
 
         if !state_word.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
+        } else if !state_word.iter().any(|&b| b != DFU_DETACH_MAGIC) {
+            Ok(State::DfuDetach)
         } else {
             Ok(State::Boot)
         }
diff --git a/embassy-boot/boot/src/firmware_updater/asynch.rs b/embassy-boot/boot/src/firmware_updater/asynch.rs
index ae713bb6f..d8d85c3d2 100644
--- a/embassy-boot/boot/src/firmware_updater/asynch.rs
+++ b/embassy-boot/boot/src/firmware_updater/asynch.rs
@@ -6,7 +6,7 @@ use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use embedded_storage_async::nor_flash::NorFlash;
 
 use super::FirmwareUpdaterConfig;
-use crate::{FirmwareUpdaterError, State, BOOT_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
+use crate::{FirmwareUpdaterError, State, BOOT_MAGIC, DFU_DETACH_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
 
 /// FirmwareUpdater is an application API for interacting with the BootLoader without the ability to
 /// 'mess up' the internal bootloader state
@@ -161,6 +161,12 @@ impl<'d, DFU: NorFlash, STATE: NorFlash> FirmwareUpdater<'d, DFU, STATE> {
         self.state.mark_updated().await
     }
 
+    /// Mark to trigger USB DFU on next boot.
+    pub async fn mark_dfu(&mut self) -> Result<(), FirmwareUpdaterError> {
+        self.state.verify_booted().await?;
+        self.state.mark_dfu().await
+    }
+
     /// Mark firmware boot successful and stop rollback on reset.
     pub async fn mark_booted(&mut self) -> Result<(), FirmwareUpdaterError> {
         self.state.mark_booted().await
@@ -207,6 +213,16 @@ pub struct FirmwareState<'d, STATE> {
 }
 
 impl<'d, STATE: NorFlash> FirmwareState<'d, STATE> {
+    /// Create a firmware state instance from a FirmwareUpdaterConfig with a buffer for magic content and state partition.
+    ///
+    /// # Safety
+    ///
+    /// The `aligned` buffer must have a size of STATE::WRITE_SIZE, and follow the alignment rules for the flash being read from
+    /// and written to.
+    pub fn from_config<DFU: NorFlash>(config: FirmwareUpdaterConfig<DFU, STATE>, aligned: &'d mut [u8]) -> Self {
+        Self::new(config.state, aligned)
+    }
+
     /// Create a firmware state instance with a buffer for magic content and state partition.
     ///
     /// # Safety
@@ -247,6 +263,11 @@ impl<'d, STATE: NorFlash> FirmwareState<'d, STATE> {
         self.set_magic(SWAP_MAGIC).await
     }
 
+    /// Mark to trigger USB DFU on next boot.
+    pub async fn mark_dfu(&mut self) -> Result<(), FirmwareUpdaterError> {
+        self.set_magic(DFU_DETACH_MAGIC).await
+    }
+
     /// Mark firmware boot successful and stop rollback on reset.
     pub async fn mark_booted(&mut self) -> Result<(), FirmwareUpdaterError> {
         self.set_magic(BOOT_MAGIC).await
diff --git a/embassy-boot/boot/src/firmware_updater/blocking.rs b/embassy-boot/boot/src/firmware_updater/blocking.rs
index 76e4264a0..c4c142169 100644
--- a/embassy-boot/boot/src/firmware_updater/blocking.rs
+++ b/embassy-boot/boot/src/firmware_updater/blocking.rs
@@ -6,7 +6,7 @@ use embassy_sync::blocking_mutex::raw::NoopRawMutex;
 use embedded_storage::nor_flash::NorFlash;
 
 use super::FirmwareUpdaterConfig;
-use crate::{FirmwareUpdaterError, State, BOOT_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
+use crate::{FirmwareUpdaterError, State, BOOT_MAGIC, DFU_DETACH_MAGIC, STATE_ERASE_VALUE, SWAP_MAGIC};
 
 /// Blocking FirmwareUpdater is an application API for interacting with the BootLoader without the ability to
 /// 'mess up' the internal bootloader state
@@ -168,6 +168,12 @@ impl<'d, DFU: NorFlash, STATE: NorFlash> BlockingFirmwareUpdater<'d, DFU, STATE>
         self.state.mark_updated()
     }
 
+    /// Mark to trigger USB DFU device on next boot.
+    pub fn mark_dfu(&mut self) -> Result<(), FirmwareUpdaterError> {
+        self.state.verify_booted()?;
+        self.state.mark_dfu()
+    }
+
     /// Mark firmware boot successful and stop rollback on reset.
     pub fn mark_booted(&mut self) -> Result<(), FirmwareUpdaterError> {
         self.state.mark_booted()
@@ -213,6 +219,16 @@ pub struct BlockingFirmwareState<'d, STATE> {
 }
 
 impl<'d, STATE: NorFlash> BlockingFirmwareState<'d, STATE> {
+    /// Creates a firmware state instance from a FirmwareUpdaterConfig, with a buffer for magic content and state partition.
+    ///
+    /// # Safety
+    ///
+    /// The `aligned` buffer must have a size of STATE::WRITE_SIZE, and follow the alignment rules for the flash being read from
+    /// and written to.
+    pub fn from_config<DFU: NorFlash>(config: FirmwareUpdaterConfig<DFU, STATE>, aligned: &'d mut [u8]) -> Self {
+        Self::new(config.state, aligned)
+    }
+
     /// Create a firmware state instance with a buffer for magic content and state partition.
     ///
     /// # Safety
@@ -226,7 +242,7 @@ impl<'d, STATE: NorFlash> BlockingFirmwareState<'d, STATE> {
 
     // Make sure we are running a booted firmware to avoid reverting to a bad state.
     fn verify_booted(&mut self) -> Result<(), FirmwareUpdaterError> {
-        if self.get_state()? == State::Boot {
+        if self.get_state()? == State::Boot || self.get_state()? == State::DfuDetach {
             Ok(())
         } else {
             Err(FirmwareUpdaterError::BadState)
@@ -243,6 +259,8 @@ impl<'d, STATE: NorFlash> BlockingFirmwareState<'d, STATE> {
 
         if !self.aligned.iter().any(|&b| b != SWAP_MAGIC) {
             Ok(State::Swap)
+        } else if !self.aligned.iter().any(|&b| b != DFU_DETACH_MAGIC) {
+            Ok(State::DfuDetach)
         } else {
             Ok(State::Boot)
         }
@@ -253,6 +271,11 @@ impl<'d, STATE: NorFlash> BlockingFirmwareState<'d, STATE> {
         self.set_magic(SWAP_MAGIC)
     }
 
+    /// Mark to trigger USB DFU on next boot.
+    pub fn mark_dfu(&mut self) -> Result<(), FirmwareUpdaterError> {
+        self.set_magic(DFU_DETACH_MAGIC)
+    }
+
     /// Mark firmware boot successful and stop rollback on reset.
     pub fn mark_booted(&mut self) -> Result<(), FirmwareUpdaterError> {
         self.set_magic(BOOT_MAGIC)
diff --git a/embassy-boot/boot/src/lib.rs b/embassy-boot/boot/src/lib.rs
index 9e70a4dca..15b69f69d 100644
--- a/embassy-boot/boot/src/lib.rs
+++ b/embassy-boot/boot/src/lib.rs
@@ -23,6 +23,7 @@ pub use firmware_updater::{
 
 pub(crate) const BOOT_MAGIC: u8 = 0xD0;
 pub(crate) const SWAP_MAGIC: u8 = 0xF0;
+pub(crate) const DFU_DETACH_MAGIC: u8 = 0xE0;
 
 /// The state of the bootloader after running prepare.
 #[derive(PartialEq, Eq, Debug)]
@@ -32,6 +33,8 @@ pub enum State {
     Boot,
     /// Bootloader has swapped the active partition with the dfu partition and will attempt boot.
     Swap,
+    /// Application has received a request to reboot into DFU mode to apply an update.
+    DfuDetach,
 }
 
 /// Buffer aligned to 32 byte boundary, largest known alignment requirement for embassy-boot.
diff --git a/embassy-boot/stm32/src/lib.rs b/embassy-boot/stm32/src/lib.rs
index c418cb262..4b4091ac9 100644
--- a/embassy-boot/stm32/src/lib.rs
+++ b/embassy-boot/stm32/src/lib.rs
@@ -10,7 +10,10 @@ pub use embassy_boot::{
 use embedded_storage::nor_flash::NorFlash;
 
 /// A bootloader for STM32 devices.
-pub struct BootLoader;
+pub struct BootLoader {
+    /// The reported state of the bootloader after preparing for boot
+    pub state: State,
+}
 
 impl BootLoader {
     /// Inspect the bootloader state and perform actions required before booting, such as swapping firmware
@@ -19,8 +22,8 @@ impl BootLoader {
     ) -> Self {
         let mut aligned_buf = AlignedBuffer([0; BUFFER_SIZE]);
         let mut boot = embassy_boot::BootLoader::new(config);
-        boot.prepare_boot(aligned_buf.as_mut()).expect("Boot prepare error");
-        Self
+        let state = boot.prepare_boot(aligned_buf.as_mut()).expect("Boot prepare error");
+        Self { state }
     }
 
     /// Boots the application.
diff --git a/embassy-usb-dfu/Cargo.toml b/embassy-usb-dfu/Cargo.toml
new file mode 100644
index 000000000..ee110ee87
--- /dev/null
+++ b/embassy-usb-dfu/Cargo.toml
@@ -0,0 +1,32 @@
+[package]
+edition = "2021"
+name = "embassy-usb-dfu"
+version = "0.1.0"
+description = "An implementation of the USB DFU 1.1 protocol, using embassy-boot"
+license = "MIT OR Apache-2.0"
+repository = "https://github.com/embassy-rs/embassy"
+categories = [
+    "embedded",
+    "no-std",
+    "asynchronous"
+]
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+bitflags = "2.4.1"
+cortex-m = { version = "0.7.7", features = ["inline-asm"], optional = true }
+defmt = { version = "0.3.5", optional = true }
+embassy-boot = { version = "0.1.1", path = "../embassy-boot/boot" }
+# embassy-embedded-hal = { version = "0.1.0", path = "../embassy-embedded-hal" }
+embassy-futures = { version = "0.1.1", path = "../embassy-futures" }
+embassy-sync = { version = "0.5.0", path = "../embassy-sync" }
+embassy-time = { version = "0.2.0", path = "../embassy-time" }
+embassy-usb = { version = "0.1.0", path = "../embassy-usb", default-features = false }
+embedded-storage = { version = "0.3.1" }
+esp32c3-hal = { version = "0.13.0", optional = true, default-features = false }
+
+[features]
+dfu = []
+application = []
+defmt = ["dep:defmt"]
diff --git a/embassy-usb-dfu/src/application.rs b/embassy-usb-dfu/src/application.rs
new file mode 100644
index 000000000..75689db26
--- /dev/null
+++ b/embassy-usb-dfu/src/application.rs
@@ -0,0 +1,135 @@
+use core::marker::PhantomData;
+
+use embassy_boot::BlockingFirmwareState;
+use embassy_time::{Duration, Instant};
+use embassy_usb::control::{InResponse, OutResponse, Recipient, RequestType};
+use embassy_usb::driver::Driver;
+use embassy_usb::{Builder, Handler};
+use embedded_storage::nor_flash::NorFlash;
+
+use crate::consts::{
+    DfuAttributes, Request, State, Status, APPN_SPEC_SUBCLASS_DFU, DESC_DFU_FUNCTIONAL, DFU_PROTOCOL_RT,
+    USB_CLASS_APPN_SPEC,
+};
+use crate::Reset;
+
+/// Internal state for the DFU class
+pub struct Control<'d, STATE: NorFlash, RST: Reset> {
+    firmware_state: BlockingFirmwareState<'d, STATE>,
+    attrs: DfuAttributes,
+    state: State,
+    timeout: Option<Duration>,
+    detach_start: Option<Instant>,
+    _rst: PhantomData<RST>,
+}
+
+impl<'d, STATE: NorFlash, RST: Reset> Control<'d, STATE, RST> {
+    pub fn new(firmware_state: BlockingFirmwareState<'d, STATE>, attrs: DfuAttributes) -> Self {
+        Control {
+            firmware_state,
+            attrs,
+            state: State::AppIdle,
+            detach_start: None,
+            timeout: None,
+            _rst: PhantomData,
+        }
+    }
+}
+
+impl<'d, STATE: NorFlash, RST: Reset> Handler for Control<'d, STATE, RST> {
+    fn reset(&mut self) {
+        if let Some(start) = self.detach_start {
+            let delta = Instant::now() - start;
+            let timeout = self.timeout.unwrap();
+            trace!(
+                "Received RESET with delta = {}, timeout = {}",
+                delta.as_millis(),
+                timeout.as_millis()
+            );
+            if delta < timeout {
+                self.firmware_state
+                    .mark_dfu()
+                    .expect("Failed to mark DFU mode in bootloader");
+                RST::sys_reset()
+            }
+        }
+    }
+
+    fn control_out(
+        &mut self,
+        req: embassy_usb::control::Request,
+        _: &[u8],
+    ) -> Option<embassy_usb::control::OutResponse> {
+        if (req.request_type, req.recipient) != (RequestType::Class, Recipient::Interface) {
+            return None;
+        }
+
+        trace!("Received request {}", req);
+
+        match Request::try_from(req.request) {
+            Ok(Request::Detach) => {
+                trace!("Received DETACH, awaiting USB reset");
+                self.detach_start = Some(Instant::now());
+                self.timeout = Some(Duration::from_millis(req.value as u64));
+                self.state = State::AppDetach;
+                Some(OutResponse::Accepted)
+            }
+            _ => None,
+        }
+    }
+
+    fn control_in<'a>(
+        &'a mut self,
+        req: embassy_usb::control::Request,
+        buf: &'a mut [u8],
+    ) -> Option<embassy_usb::control::InResponse<'a>> {
+        if (req.request_type, req.recipient) != (RequestType::Class, Recipient::Interface) {
+            return None;
+        }
+
+        trace!("Received request {}", req);
+
+        match Request::try_from(req.request) {
+            Ok(Request::GetStatus) => {
+                buf[0..6].copy_from_slice(&[Status::Ok as u8, 0x32, 0x00, 0x00, self.state as u8, 0x00]);
+                Some(InResponse::Accepted(buf))
+            }
+            _ => None,
+        }
+    }
+}
+
+/// An implementation of the USB DFU 1.1 runtime protocol
+///
+/// This function will add a DFU interface descriptor to the provided Builder, and register the provided Control as a handler for the USB device. The USB builder can be used as normal once this is complete.
+/// The handler is responsive to DFU GetStatus and Detach commands.
+///
+/// Once a detach command, followed by a USB reset is received by the host, a magic number will be written into the bootloader state partition to indicate that
+/// it should expose a DFU device, and a software reset will be issued.
+///
+/// To apply USB DFU updates, the bootloader must be capable of recognizing the DFU magic and exposing a device to handle the full DFU transaction with the host.
+pub fn usb_dfu<'d, D: Driver<'d>, STATE: NorFlash, RST: Reset>(
+    builder: &mut Builder<'d, D>,
+    handler: &'d mut Control<'d, STATE, RST>,
+    timeout: Duration,
+) {
+    let mut func = builder.function(0x00, 0x00, 0x00);
+    let mut iface = func.interface();
+    let mut alt = iface.alt_setting(USB_CLASS_APPN_SPEC, APPN_SPEC_SUBCLASS_DFU, DFU_PROTOCOL_RT, None);
+    let timeout = timeout.as_millis() as u16;
+    alt.descriptor(
+        DESC_DFU_FUNCTIONAL,
+        &[
+            handler.attrs.bits(),
+            (timeout & 0xff) as u8,
+            ((timeout >> 8) & 0xff) as u8,
+            0x40,
+            0x00, // 64B control buffer size for application side
+            0x10,
+            0x01, // DFU 1.1
+        ],
+    );
+
+    drop(func);
+    builder.handler(handler);
+}
diff --git a/embassy-usb-dfu/src/bootloader.rs b/embassy-usb-dfu/src/bootloader.rs
new file mode 100644
index 000000000..d41e6280d
--- /dev/null
+++ b/embassy-usb-dfu/src/bootloader.rs
@@ -0,0 +1,189 @@
+use core::marker::PhantomData;
+
+use embassy_boot::{AlignedBuffer, BlockingFirmwareUpdater};
+use embassy_usb::control::{InResponse, OutResponse, Recipient, RequestType};
+use embassy_usb::driver::Driver;
+use embassy_usb::{Builder, Handler};
+use embedded_storage::nor_flash::{NorFlash, NorFlashErrorKind};
+
+use crate::consts::{
+    DfuAttributes, Request, State, Status, APPN_SPEC_SUBCLASS_DFU, DESC_DFU_FUNCTIONAL, DFU_PROTOCOL_DFU,
+    USB_CLASS_APPN_SPEC,
+};
+use crate::Reset;
+
+/// Internal state for USB DFU
+pub struct Control<'d, DFU: NorFlash, STATE: NorFlash, RST: Reset, const BLOCK_SIZE: usize> {
+    updater: BlockingFirmwareUpdater<'d, DFU, STATE>,
+    attrs: DfuAttributes,
+    state: State,
+    status: Status,
+    offset: usize,
+    _rst: PhantomData<RST>,
+}
+
+impl<'d, DFU: NorFlash, STATE: NorFlash, RST: Reset, const BLOCK_SIZE: usize> Control<'d, DFU, STATE, RST, BLOCK_SIZE> {
+    pub fn new(updater: BlockingFirmwareUpdater<'d, DFU, STATE>, attrs: DfuAttributes) -> Self {
+        Self {
+            updater,
+            attrs,
+            state: State::DfuIdle,
+            status: Status::Ok,
+            offset: 0,
+            _rst: PhantomData,
+        }
+    }
+
+    fn reset_state(&mut self) {
+        self.offset = 0;
+        self.state = State::DfuIdle;
+        self.status = Status::Ok;
+    }
+}
+
+impl<'d, DFU: NorFlash, STATE: NorFlash, RST: Reset, const BLOCK_SIZE: usize> Handler
+    for Control<'d, DFU, STATE, RST, BLOCK_SIZE>
+{
+    fn control_out(
+        &mut self,
+        req: embassy_usb::control::Request,
+        data: &[u8],
+    ) -> Option<embassy_usb::control::OutResponse> {
+        if (req.request_type, req.recipient) != (RequestType::Class, Recipient::Interface) {
+            return None;
+        }
+        match Request::try_from(req.request) {
+            Ok(Request::Abort) => {
+                self.reset_state();
+                Some(OutResponse::Accepted)
+            }
+            Ok(Request::Dnload) if self.attrs.contains(DfuAttributes::CAN_DOWNLOAD) => {
+                if req.value == 0 {
+                    self.state = State::Download;
+                    self.offset = 0;
+                }
+
+                let mut buf = AlignedBuffer([0; BLOCK_SIZE]);
+                buf.as_mut()[..data.len()].copy_from_slice(data);
+
+                if req.length == 0 {
+                    match self.updater.mark_updated() {
+                        Ok(_) => {
+                            self.status = Status::Ok;
+                            self.state = State::ManifestSync;
+                        }
+                        Err(e) => {
+                            self.state = State::Error;
+                            match e {
+                                embassy_boot::FirmwareUpdaterError::Flash(e) => match e {
+                                    NorFlashErrorKind::NotAligned => self.status = Status::ErrWrite,
+                                    NorFlashErrorKind::OutOfBounds => self.status = Status::ErrAddress,
+                                    _ => self.status = Status::ErrUnknown,
+                                },
+                                embassy_boot::FirmwareUpdaterError::Signature(_) => self.status = Status::ErrVerify,
+                                embassy_boot::FirmwareUpdaterError::BadState => self.status = Status::ErrUnknown,
+                            }
+                        }
+                    }
+                } else {
+                    if self.state != State::Download {
+                        // Unexpected DNLOAD while chip is waiting for a GETSTATUS
+                        self.status = Status::ErrUnknown;
+                        self.state = State::Error;
+                        return Some(OutResponse::Rejected);
+                    }
+                    match self.updater.write_firmware(self.offset, buf.as_ref()) {
+                        Ok(_) => {
+                            self.status = Status::Ok;
+                            self.state = State::DlSync;
+                            self.offset += data.len();
+                        }
+                        Err(e) => {
+                            self.state = State::Error;
+                            match e {
+                                embassy_boot::FirmwareUpdaterError::Flash(e) => match e {
+                                    NorFlashErrorKind::NotAligned => self.status = Status::ErrWrite,
+                                    NorFlashErrorKind::OutOfBounds => self.status = Status::ErrAddress,
+                                    _ => self.status = Status::ErrUnknown,
+                                },
+                                embassy_boot::FirmwareUpdaterError::Signature(_) => self.status = Status::ErrVerify,
+                                embassy_boot::FirmwareUpdaterError::BadState => self.status = Status::ErrUnknown,
+                            }
+                        }
+                    }
+                }
+
+                Some(OutResponse::Accepted)
+            }
+            Ok(Request::Detach) => Some(OutResponse::Accepted), // Device is already in DFU mode
+            Ok(Request::ClrStatus) => {
+                self.reset_state();
+                Some(OutResponse::Accepted)
+            }
+            _ => None,
+        }
+    }
+
+    fn control_in<'a>(
+        &'a mut self,
+        req: embassy_usb::control::Request,
+        buf: &'a mut [u8],
+    ) -> Option<embassy_usb::control::InResponse<'a>> {
+        if (req.request_type, req.recipient) != (RequestType::Class, Recipient::Interface) {
+            return None;
+        }
+        match Request::try_from(req.request) {
+            Ok(Request::GetStatus) => {
+                //TODO: Configurable poll timeout, ability to add string for Vendor error
+                buf[0..6].copy_from_slice(&[self.status as u8, 0x32, 0x00, 0x00, self.state as u8, 0x00]);
+                match self.state {
+                    State::DlSync => self.state = State::Download,
+                    State::ManifestSync => RST::sys_reset(),
+                    _ => {}
+                }
+
+                Some(InResponse::Accepted(&buf[0..6]))
+            }
+            Ok(Request::GetState) => {
+                buf[0] = self.state as u8;
+                Some(InResponse::Accepted(&buf[0..1]))
+            }
+            Ok(Request::Upload) if self.attrs.contains(DfuAttributes::CAN_UPLOAD) => {
+                //TODO: FirmwareUpdater does not provide a way of reading the active partition, can't upload.
+                Some(InResponse::Rejected)
+            }
+            _ => None,
+        }
+    }
+}
+
+/// An implementation of the USB DFU 1.1 protocol
+///
+/// This function will add a DFU interface descriptor to the provided Builder, and register the provided Control as a handler for the USB device
+/// The handler is responsive to DFU GetState, GetStatus, Abort, and ClrStatus commands, as well as Download if configured by the user.
+///
+/// Once the host has initiated a DFU download operation, the chunks sent by the host will be written to the DFU partition.
+/// Once the final sync in the manifestation phase has been received, the handler will trigger a system reset to swap the new firmware.
+pub fn usb_dfu<'d, D: Driver<'d>, DFU: NorFlash, STATE: NorFlash, RST: Reset, const BLOCK_SIZE: usize>(
+    builder: &mut Builder<'d, D>,
+    handler: &'d mut Control<'d, DFU, STATE, RST, BLOCK_SIZE>,
+) {
+    let mut func = builder.function(0x00, 0x00, 0x00);
+    let mut iface = func.interface();
+    let mut alt = iface.alt_setting(USB_CLASS_APPN_SPEC, APPN_SPEC_SUBCLASS_DFU, DFU_PROTOCOL_DFU, None);
+    alt.descriptor(
+        DESC_DFU_FUNCTIONAL,
+        &[
+            handler.attrs.bits(),
+            0xc4,
+            0x09, // 2500ms timeout, doesn't affect operation as DETACH not necessary in bootloader code
+            (BLOCK_SIZE & 0xff) as u8,
+            ((BLOCK_SIZE & 0xff00) >> 8) as u8,
+            0x10,
+            0x01, // DFU 1.1
+        ],
+    );
+
+    drop(func);
+    builder.handler(handler);
+}
diff --git a/embassy-usb-dfu/src/consts.rs b/embassy-usb-dfu/src/consts.rs
new file mode 100644
index 000000000..b359a107e
--- /dev/null
+++ b/embassy-usb-dfu/src/consts.rs
@@ -0,0 +1,95 @@
+pub(crate) const USB_CLASS_APPN_SPEC: u8 = 0xFE;
+pub(crate) const APPN_SPEC_SUBCLASS_DFU: u8 = 0x01;
+#[allow(unused)]
+pub(crate) const DFU_PROTOCOL_DFU: u8 = 0x02;
+#[allow(unused)]
+pub(crate) const DFU_PROTOCOL_RT: u8 = 0x01;
+pub(crate) const DESC_DFU_FUNCTIONAL: u8 = 0x21;
+
+#[cfg(feature = "defmt")]
+defmt::bitflags! {
+    pub struct DfuAttributes: u8 {
+        const WILL_DETACH = 0b0000_1000;
+        const MANIFESTATION_TOLERANT = 0b0000_0100;
+        const CAN_UPLOAD = 0b0000_0010;
+        const CAN_DOWNLOAD = 0b0000_0001;
+    }
+}
+
+#[cfg(not(feature = "defmt"))]
+bitflags::bitflags! {
+    pub struct DfuAttributes: u8 {
+        const WILL_DETACH = 0b0000_1000;
+        const MANIFESTATION_TOLERANT = 0b0000_0100;
+        const CAN_UPLOAD = 0b0000_0010;
+        const CAN_DOWNLOAD = 0b0000_0001;
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(u8)]
+#[allow(unused)]
+pub enum State {
+    AppIdle = 0,
+    AppDetach = 1,
+    DfuIdle = 2,
+    DlSync = 3,
+    DlBusy = 4,
+    Download = 5,
+    ManifestSync = 6,
+    Manifest = 7,
+    ManifestWaitReset = 8,
+    UploadIdle = 9,
+    Error = 10,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(u8)]
+#[allow(unused)]
+pub enum Status {
+    Ok = 0x00,
+    ErrTarget = 0x01,
+    ErrFile = 0x02,
+    ErrWrite = 0x03,
+    ErrErase = 0x04,
+    ErrCheckErased = 0x05,
+    ErrProg = 0x06,
+    ErrVerify = 0x07,
+    ErrAddress = 0x08,
+    ErrNotDone = 0x09,
+    ErrFirmware = 0x0A,
+    ErrVendor = 0x0B,
+    ErrUsbr = 0x0C,
+    ErrPor = 0x0D,
+    ErrUnknown = 0x0E,
+    ErrStalledPkt = 0x0F,
+}
+
+#[derive(Copy, Clone, PartialEq, Eq)]
+#[repr(u8)]
+pub enum Request {
+    Detach = 0,
+    Dnload = 1,
+    Upload = 2,
+    GetStatus = 3,
+    ClrStatus = 4,
+    GetState = 5,
+    Abort = 6,
+}
+
+impl TryFrom<u8> for Request {
+    type Error = ();
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        match value {
+            0 => Ok(Request::Detach),
+            1 => Ok(Request::Dnload),
+            2 => Ok(Request::Upload),
+            3 => Ok(Request::GetStatus),
+            4 => Ok(Request::ClrStatus),
+            5 => Ok(Request::GetState),
+            6 => Ok(Request::Abort),
+            _ => Err(()),
+        }
+    }
+}
diff --git a/embassy-usb-dfu/src/fmt.rs b/embassy-usb-dfu/src/fmt.rs
new file mode 100644
index 000000000..78e583c1c
--- /dev/null
+++ b/embassy-usb-dfu/src/fmt.rs
@@ -0,0 +1,258 @@
+#![macro_use]
+#![allow(unused_macros)]
+
+use core::fmt::{Debug, Display, LowerHex};
+
+#[cfg(all(feature = "defmt", feature = "log"))]
+compile_error!("You may not enable both `defmt` and `log` features.");
+
+macro_rules! assert {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::assert!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::assert!($($x)*);
+        }
+    };
+}
+
+macro_rules! assert_eq {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::assert_eq!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::assert_eq!($($x)*);
+        }
+    };
+}
+
+macro_rules! assert_ne {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::assert_ne!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::assert_ne!($($x)*);
+        }
+    };
+}
+
+macro_rules! debug_assert {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::debug_assert!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::debug_assert!($($x)*);
+        }
+    };
+}
+
+macro_rules! debug_assert_eq {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::debug_assert_eq!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::debug_assert_eq!($($x)*);
+        }
+    };
+}
+
+macro_rules! debug_assert_ne {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::debug_assert_ne!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::debug_assert_ne!($($x)*);
+        }
+    };
+}
+
+macro_rules! todo {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::todo!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::todo!($($x)*);
+        }
+    };
+}
+
+#[cfg(not(feature = "defmt"))]
+macro_rules! unreachable {
+    ($($x:tt)*) => {
+        ::core::unreachable!($($x)*)
+    };
+}
+
+#[cfg(feature = "defmt")]
+macro_rules! unreachable {
+    ($($x:tt)*) => {
+        ::defmt::unreachable!($($x)*)
+    };
+}
+
+macro_rules! panic {
+    ($($x:tt)*) => {
+        {
+            #[cfg(not(feature = "defmt"))]
+            ::core::panic!($($x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::panic!($($x)*);
+        }
+    };
+}
+
+macro_rules! trace {
+    ($s:literal $(, $x:expr)* $(,)?) => {
+        {
+            #[cfg(feature = "log")]
+            ::log::trace!($s $(, $x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::trace!($s $(, $x)*);
+            #[cfg(not(any(feature = "log", feature="defmt")))]
+            let _ = ($( & $x ),*);
+        }
+    };
+}
+
+macro_rules! debug {
+    ($s:literal $(, $x:expr)* $(,)?) => {
+        {
+            #[cfg(feature = "log")]
+            ::log::debug!($s $(, $x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::debug!($s $(, $x)*);
+            #[cfg(not(any(feature = "log", feature="defmt")))]
+            let _ = ($( & $x ),*);
+        }
+    };
+}
+
+macro_rules! info {
+    ($s:literal $(, $x:expr)* $(,)?) => {
+        {
+            #[cfg(feature = "log")]
+            ::log::info!($s $(, $x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::info!($s $(, $x)*);
+            #[cfg(not(any(feature = "log", feature="defmt")))]
+            let _ = ($( & $x ),*);
+        }
+    };
+}
+
+macro_rules! warn {
+    ($s:literal $(, $x:expr)* $(,)?) => {
+        {
+            #[cfg(feature = "log")]
+            ::log::warn!($s $(, $x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::warn!($s $(, $x)*);
+            #[cfg(not(any(feature = "log", feature="defmt")))]
+            let _ = ($( & $x ),*);
+        }
+    };
+}
+
+macro_rules! error {
+    ($s:literal $(, $x:expr)* $(,)?) => {
+        {
+            #[cfg(feature = "log")]
+            ::log::error!($s $(, $x)*);
+            #[cfg(feature = "defmt")]
+            ::defmt::error!($s $(, $x)*);
+            #[cfg(not(any(feature = "log", feature="defmt")))]
+            let _ = ($( & $x ),*);
+        }
+    };
+}
+
+#[cfg(feature = "defmt")]
+macro_rules! unwrap {
+    ($($x:tt)*) => {
+        ::defmt::unwrap!($($x)*)
+    };
+}
+
+#[cfg(not(feature = "defmt"))]
+macro_rules! unwrap {
+    ($arg:expr) => {
+        match $crate::fmt::Try::into_result($arg) {
+            ::core::result::Result::Ok(t) => t,
+            ::core::result::Result::Err(e) => {
+                ::core::panic!("unwrap of `{}` failed: {:?}", ::core::stringify!($arg), e);
+            }
+        }
+    };
+    ($arg:expr, $($msg:expr),+ $(,)? ) => {
+        match $crate::fmt::Try::into_result($arg) {
+            ::core::result::Result::Ok(t) => t,
+            ::core::result::Result::Err(e) => {
+                ::core::panic!("unwrap of `{}` failed: {}: {:?}", ::core::stringify!($arg), ::core::format_args!($($msg,)*), e);
+            }
+        }
+    }
+}
+
+#[derive(Debug, Copy, Clone, Eq, PartialEq)]
+pub struct NoneError;
+
+pub trait Try {
+    type Ok;
+    type Error;
+    fn into_result(self) -> Result<Self::Ok, Self::Error>;
+}
+
+impl<T> Try for Option<T> {
+    type Ok = T;
+    type Error = NoneError;
+
+    #[inline]
+    fn into_result(self) -> Result<T, NoneError> {
+        self.ok_or(NoneError)
+    }
+}
+
+impl<T, E> Try for Result<T, E> {
+    type Ok = T;
+    type Error = E;
+
+    #[inline]
+    fn into_result(self) -> Self {
+        self
+    }
+}
+
+#[allow(unused)]
+pub(crate) struct Bytes<'a>(pub &'a [u8]);
+
+impl<'a> Debug for Bytes<'a> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{:#02x?}", self.0)
+    }
+}
+
+impl<'a> Display for Bytes<'a> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{:#02x?}", self.0)
+    }
+}
+
+impl<'a> LowerHex for Bytes<'a> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{:#02x?}", self.0)
+    }
+}
+
+#[cfg(feature = "defmt")]
+impl<'a> defmt::Format for Bytes<'a> {
+    fn format(&self, fmt: defmt::Formatter) {
+        defmt::write!(fmt, "{:02x}", self.0)
+    }
+}
diff --git a/embassy-usb-dfu/src/lib.rs b/embassy-usb-dfu/src/lib.rs
new file mode 100644
index 000000000..389bb33f2
--- /dev/null
+++ b/embassy-usb-dfu/src/lib.rs
@@ -0,0 +1,51 @@
+#![no_std]
+mod fmt;
+
+pub mod consts;
+
+#[cfg(feature = "dfu")]
+mod bootloader;
+#[cfg(feature = "dfu")]
+pub use self::bootloader::*;
+
+#[cfg(feature = "application")]
+mod application;
+#[cfg(feature = "application")]
+pub use self::application::*;
+
+#[cfg(any(
+    all(feature = "dfu", feature = "application"),
+    not(any(feature = "dfu", feature = "application"))
+))]
+compile_error!("usb-dfu must be compiled with exactly one of `bootloader`, or `application` features");
+
+/// Provides a platform-agnostic interface for initiating a system reset.
+///
+/// This crate exposes `ResetImmediate` when compiled with cortex-m or esp32c3 support, which immediately issues a
+/// reset request without interfacing with any other peripherals.
+///
+/// If alternate behaviour is desired, a custom implementation of Reset can be provided as a type argument to the usb_dfu function.
+pub trait Reset {
+    fn sys_reset() -> !;
+}
+
+#[cfg(feature = "esp32c3-hal")]
+pub struct ResetImmediate;
+
+#[cfg(feature = "esp32c3-hal")]
+impl Reset for ResetImmediate {
+    fn sys_reset() -> ! {
+        esp32c3_hal::reset::software_reset();
+        loop {}
+    }
+}
+
+#[cfg(feature = "cortex-m")]
+pub struct ResetImmediate;
+
+#[cfg(feature = "cortex-m")]
+impl Reset for ResetImmediate {
+    fn sys_reset() -> ! {
+        cortex_m::peripheral::SCB::sys_reset()
+    }
+}
diff --git a/examples/boot/application/stm32wb-dfu/.cargo/config.toml b/examples/boot/application/stm32wb-dfu/.cargo/config.toml
new file mode 100644
index 000000000..4f8094ff2
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/.cargo/config.toml
@@ -0,0 +1,9 @@
+[target.'cfg(all(target_arch = "arm", target_os = "none"))']
+# replace your chip as listed in `probe-rs chip list`
+runner = "probe-rs run --chip STM32WLE5JCIx"
+
+[build]
+target = "thumbv7em-none-eabihf"
+
+[env]
+DEFMT_LOG = "trace"
diff --git a/examples/boot/application/stm32wb-dfu/Cargo.toml b/examples/boot/application/stm32wb-dfu/Cargo.toml
new file mode 100644
index 000000000..f6beea498
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/Cargo.toml
@@ -0,0 +1,32 @@
+[package]
+edition = "2021"
+name = "embassy-boot-stm32wb-dfu-examples"
+version = "0.1.0"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+embassy-sync = { version = "0.5.0", path = "../../../../embassy-sync" }
+embassy-executor = { version = "0.4.0", path = "../../../../embassy-executor", features = ["arch-cortex-m", "executor-thread", "nightly", "integrated-timers"] }
+embassy-time = { version = "0.2", path = "../../../../embassy-time", features = [ "tick-hz-32_768"] }
+embassy-stm32 = { version = "0.1.0", path = "../../../../embassy-stm32", features = ["stm32wb55rg", "time-driver-any", "exti"]  }
+embassy-boot-stm32 = { version = "0.1.0", path = "../../../../embassy-boot/stm32", features = [] }
+embassy-embedded-hal = { version = "0.1.0", path = "../../../../embassy-embedded-hal" }
+embassy-usb = { version = "0.1.0", path = "../../../../embassy-usb" }
+embassy-usb-dfu = { version = "0.1.0", path = "../../../../embassy-usb-dfu", features = ["application", "cortex-m"] }
+
+defmt = { version = "0.3", optional = true }
+defmt-rtt = { version = "0.4", optional = true }
+panic-reset = { version = "0.1.1" }
+embedded-hal = { version = "0.2.6" }
+
+cortex-m = { version = "0.7.6", features = ["inline-asm", "critical-section-single-core"] }
+cortex-m-rt = "0.7.0"
+
+[features]
+defmt = [
+      "dep:defmt",
+      "dep:defmt-rtt",
+      "embassy-stm32/defmt",
+      "embassy-boot-stm32/defmt",
+      "embassy-sync/defmt",
+]
diff --git a/examples/boot/application/stm32wb-dfu/README.md b/examples/boot/application/stm32wb-dfu/README.md
new file mode 100644
index 000000000..c8dce0387
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/README.md
@@ -0,0 +1,29 @@
+# Examples using bootloader
+
+Example for STM32WL demonstrating the bootloader. The example consists of application binaries, 'a'
+which allows you to press a button to start the DFU process, and 'b' which is the updated
+application.
+
+
+## Prerequisites
+
+* `cargo-binutils`
+* `cargo-flash`
+* `embassy-boot-stm32`
+
+## Usage
+
+```
+# Flash bootloader
+cargo flash --manifest-path ../../bootloader/stm32/Cargo.toml --release --features embassy-stm32/stm32wl55jc-cm4 --chip STM32WLE5JCIx
+# Build 'b'
+cargo build --release --bin b
+# Generate binary for 'b'
+cargo objcopy --release --bin b -- -O binary b.bin
+```
+
+# Flash `a` (which includes b.bin)
+
+```
+cargo flash --release --bin a --chip STM32WLE5JCIx
+```
diff --git a/examples/boot/application/stm32wb-dfu/build.rs b/examples/boot/application/stm32wb-dfu/build.rs
new file mode 100644
index 000000000..e1da69328
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/build.rs
@@ -0,0 +1,37 @@
+//! This build script copies the `memory.x` file from the crate root into
+//! a directory where the linker can always find it at build time.
+//! For many projects this is optional, as the linker always searches the
+//! project root directory -- wherever `Cargo.toml` is. However, if you
+//! are using a workspace or have a more complicated build setup, this
+//! build script becomes required. Additionally, by requesting that
+//! Cargo re-run the build script whenever `memory.x` is changed,
+//! updating `memory.x` ensures a rebuild of the application with the
+//! new memory settings.
+
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink.x");
+    if env::var("CARGO_FEATURE_DEFMT").is_ok() {
+        println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+    }
+}
diff --git a/examples/boot/application/stm32wb-dfu/memory.x b/examples/boot/application/stm32wb-dfu/memory.x
new file mode 100644
index 000000000..ff1b800d2
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/memory.x
@@ -0,0 +1,15 @@
+MEMORY
+{
+  /* NOTE 1 K = 1 KiBi = 1024 bytes */
+  BOOTLOADER                        : ORIGIN = 0x08000000, LENGTH = 24K
+  BOOTLOADER_STATE                  : ORIGIN = 0x08006000, LENGTH = 4K
+  FLASH                             : ORIGIN = 0x08008000, LENGTH = 128K
+  DFU                               : ORIGIN = 0x08028000, LENGTH = 132K
+  RAM                         (rwx) : ORIGIN = 0x20000000, LENGTH = 32K
+}
+
+__bootloader_state_start = ORIGIN(BOOTLOADER_STATE) - ORIGIN(BOOTLOADER);
+__bootloader_state_end = ORIGIN(BOOTLOADER_STATE) + LENGTH(BOOTLOADER_STATE) - ORIGIN(BOOTLOADER);
+
+__bootloader_dfu_start = ORIGIN(DFU) - ORIGIN(BOOTLOADER);
+__bootloader_dfu_end = ORIGIN(DFU) + LENGTH(DFU) - ORIGIN(BOOTLOADER);
diff --git a/examples/boot/application/stm32wb-dfu/src/main.rs b/examples/boot/application/stm32wb-dfu/src/main.rs
new file mode 100644
index 000000000..fbecbf23b
--- /dev/null
+++ b/examples/boot/application/stm32wb-dfu/src/main.rs
@@ -0,0 +1,64 @@
+#![no_std]
+#![no_main]
+#![feature(type_alias_impl_trait)]
+
+use core::cell::RefCell;
+
+#[cfg(feature = "defmt-rtt")]
+use defmt_rtt::*;
+use embassy_boot_stm32::{AlignedBuffer, BlockingFirmwareState, FirmwareUpdaterConfig};
+use embassy_executor::Spawner;
+use embassy_stm32::flash::{Flash, WRITE_SIZE};
+use embassy_stm32::rcc::WPAN_DEFAULT;
+use embassy_stm32::usb::{self, Driver};
+use embassy_stm32::{bind_interrupts, peripherals};
+use embassy_sync::blocking_mutex::Mutex;
+use embassy_time::Duration;
+use embassy_usb::Builder;
+use embassy_usb_dfu::consts::DfuAttributes;
+use embassy_usb_dfu::{usb_dfu, Control, ResetImmediate};
+use panic_reset as _;
+
+bind_interrupts!(struct Irqs {
+    USB_LP => usb::InterruptHandler<peripherals::USB>;
+});
+
+#[embassy_executor::main]
+async fn main(_spawner: Spawner) {
+    let mut config = embassy_stm32::Config::default();
+    config.rcc = WPAN_DEFAULT;
+    let p = embassy_stm32::init(config);
+    let flash = Flash::new_blocking(p.FLASH);
+    let flash = Mutex::new(RefCell::new(flash));
+
+    let config = FirmwareUpdaterConfig::from_linkerfile_blocking(&flash);
+    let mut magic = AlignedBuffer([0; WRITE_SIZE]);
+    let mut firmware_state = BlockingFirmwareState::from_config(config, &mut magic.0);
+    firmware_state.mark_booted().expect("Failed to mark booted");
+
+    let driver = Driver::new(p.USB, Irqs, p.PA12, p.PA11);
+    let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
+    config.manufacturer = Some("Embassy");
+    config.product = Some("USB-DFU Runtime example");
+    config.serial_number = Some("1235678");
+
+    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 mut state = Control::new(firmware_state, DfuAttributes::CAN_DOWNLOAD);
+    let mut builder = Builder::new(
+        driver,
+        config,
+        &mut device_descriptor,
+        &mut config_descriptor,
+        &mut bos_descriptor,
+        &mut [],
+        &mut control_buf,
+    );
+
+    usb_dfu::<_, _, ResetImmediate>(&mut builder, &mut state, Duration::from_millis(2500));
+
+    let mut dev = builder.build();
+    dev.run().await
+}
diff --git a/examples/boot/bootloader/stm32wb-dfu/Cargo.toml b/examples/boot/bootloader/stm32wb-dfu/Cargo.toml
new file mode 100644
index 000000000..ada073970
--- /dev/null
+++ b/examples/boot/bootloader/stm32wb-dfu/Cargo.toml
@@ -0,0 +1,63 @@
+[package]
+edition = "2021"
+name = "stm32wb-dfu-bootloader-example"
+version = "0.1.0"
+description = "Example USB DFUbootloader for the STM32WB series of chips"
+license = "MIT OR Apache-2.0"
+
+[dependencies]
+defmt = { version = "0.3", optional = true }
+defmt-rtt = { version = "0.4", optional = true }
+
+embassy-stm32 = { path = "../../../../embassy-stm32", features = ["stm32wb55rg"] }
+embassy-boot-stm32 = { path = "../../../../embassy-boot/stm32" }
+cortex-m = { version = "0.7.6", features = ["inline-asm", "critical-section-single-core"] }
+embassy-sync = { version = "0.5.0", path = "../../../../embassy-sync" }
+cortex-m-rt = { version = "0.7" }
+embedded-storage = "0.3.1"
+embedded-storage-async = "0.4.0"
+cfg-if = "1.0.0"
+embassy-usb-dfu = { version = "0.1.0", path = "../../../../embassy-usb-dfu", features = ["dfu", "cortex-m"] }
+embassy-usb = { version = "0.1.0", path = "../../../../embassy-usb", default-features = false }
+embassy-futures = { version = "0.1.1", path = "../../../../embassy-futures" }
+
+[features]
+defmt = [
+    "dep:defmt",
+    "embassy-boot-stm32/defmt",
+    "embassy-stm32/defmt",
+    "embassy-usb/defmt",
+    "embassy-usb-dfu/defmt"
+]
+debug = ["defmt-rtt", "defmt"]
+
+[profile.dev]
+debug = 2
+debug-assertions = true
+incremental = false
+opt-level = 'z'
+overflow-checks = true
+
+[profile.release]
+codegen-units = 1
+debug = 2
+debug-assertions = false
+incremental = false
+lto = 'fat'
+opt-level = 'z'
+overflow-checks = false
+
+# do not optimize proc-macro crates = faster builds from scratch
+[profile.dev.build-override]
+codegen-units = 8
+debug = false
+debug-assertions = false
+opt-level = 0
+overflow-checks = false
+
+[profile.release.build-override]
+codegen-units = 8
+debug = false
+debug-assertions = false
+opt-level = 0
+overflow-checks = false
diff --git a/examples/boot/bootloader/stm32wb-dfu/README.md b/examples/boot/bootloader/stm32wb-dfu/README.md
new file mode 100644
index 000000000..a82b730b9
--- /dev/null
+++ b/examples/boot/bootloader/stm32wb-dfu/README.md
@@ -0,0 +1,11 @@
+# Bootloader for STM32
+
+The bootloader uses `embassy-boot` to interact with the flash.
+
+# Usage
+
+Flash the bootloader
+
+```
+cargo flash --features embassy-stm32/stm32wl55jc-cm4 --release --chip STM32WLE5JCIx
+```
diff --git a/examples/boot/bootloader/stm32wb-dfu/build.rs b/examples/boot/bootloader/stm32wb-dfu/build.rs
new file mode 100644
index 000000000..fd605991f
--- /dev/null
+++ b/examples/boot/bootloader/stm32wb-dfu/build.rs
@@ -0,0 +1,27 @@
+use std::env;
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+
+fn main() {
+    // Put `memory.x` in our output directory and ensure it's
+    // on the linker search path.
+    let out = &PathBuf::from(env::var_os("OUT_DIR").unwrap());
+    File::create(out.join("memory.x"))
+        .unwrap()
+        .write_all(include_bytes!("memory.x"))
+        .unwrap();
+    println!("cargo:rustc-link-search={}", out.display());
+
+    // By default, Cargo will re-run a build script whenever
+    // any file in the project changes. By specifying `memory.x`
+    // here, we ensure the build script is only re-run when
+    // `memory.x` is changed.
+    println!("cargo:rerun-if-changed=memory.x");
+
+    println!("cargo:rustc-link-arg-bins=--nmagic");
+    println!("cargo:rustc-link-arg-bins=-Tlink.x");
+    if env::var("CARGO_FEATURE_DEFMT").is_ok() {
+        println!("cargo:rustc-link-arg-bins=-Tdefmt.x");
+    }
+}
diff --git a/examples/boot/bootloader/stm32wb-dfu/memory.x b/examples/boot/bootloader/stm32wb-dfu/memory.x
new file mode 100644
index 000000000..858062631
--- /dev/null
+++ b/examples/boot/bootloader/stm32wb-dfu/memory.x
@@ -0,0 +1,18 @@
+MEMORY
+{
+  /* NOTE 1 K = 1 KiBi = 1024 bytes */
+  FLASH                             : ORIGIN = 0x08000000, LENGTH = 24K
+  BOOTLOADER_STATE                  : ORIGIN = 0x08006000, LENGTH = 4K
+  ACTIVE                            : ORIGIN = 0x08008000, LENGTH = 128K
+  DFU                               : ORIGIN = 0x08028000, LENGTH = 132K
+  RAM                         (rwx) : ORIGIN = 0x20000000, LENGTH = 16K
+}
+
+__bootloader_state_start = ORIGIN(BOOTLOADER_STATE) - ORIGIN(FLASH);
+__bootloader_state_end = ORIGIN(BOOTLOADER_STATE) + LENGTH(BOOTLOADER_STATE) - ORIGIN(FLASH);
+
+__bootloader_active_start = ORIGIN(ACTIVE) - ORIGIN(FLASH);
+__bootloader_active_end = ORIGIN(ACTIVE) + LENGTH(ACTIVE) - ORIGIN(FLASH);
+
+__bootloader_dfu_start = ORIGIN(DFU) - ORIGIN(FLASH);
+__bootloader_dfu_end = ORIGIN(DFU) + LENGTH(DFU) - ORIGIN(FLASH);
diff --git a/examples/boot/bootloader/stm32wb-dfu/src/main.rs b/examples/boot/bootloader/stm32wb-dfu/src/main.rs
new file mode 100644
index 000000000..a7ab813b6
--- /dev/null
+++ b/examples/boot/bootloader/stm32wb-dfu/src/main.rs
@@ -0,0 +1,93 @@
+#![no_std]
+#![no_main]
+
+use core::cell::RefCell;
+
+use cortex_m_rt::{entry, exception};
+#[cfg(feature = "defmt")]
+use defmt_rtt as _;
+use embassy_boot_stm32::*;
+use embassy_stm32::flash::{Flash, BANK1_REGION, WRITE_SIZE};
+use embassy_stm32::rcc::WPAN_DEFAULT;
+use embassy_stm32::usb::Driver;
+use embassy_stm32::{bind_interrupts, peripherals, usb};
+use embassy_sync::blocking_mutex::Mutex;
+use embassy_usb::Builder;
+use embassy_usb_dfu::consts::DfuAttributes;
+use embassy_usb_dfu::{usb_dfu, Control, ResetImmediate};
+
+bind_interrupts!(struct Irqs {
+    USB_LP => usb::InterruptHandler<peripherals::USB>;
+});
+
+#[entry]
+fn main() -> ! {
+    let mut config = embassy_stm32::Config::default();
+    config.rcc = WPAN_DEFAULT;
+    let p = embassy_stm32::init(config);
+
+    // Prevent a hard fault when accessing flash 'too early' after boot.
+    #[cfg(feature = "defmt")]
+    for _ in 0..10000000 {
+        cortex_m::asm::nop();
+    }
+
+    let layout = Flash::new_blocking(p.FLASH).into_blocking_regions();
+    let flash = Mutex::new(RefCell::new(layout.bank1_region));
+
+    let config = BootLoaderConfig::from_linkerfile_blocking(&flash);
+    let active_offset = config.active.offset();
+    let bl = BootLoader::prepare::<_, _, _, 2048>(config);
+    if bl.state == State::DfuDetach {
+        let driver = Driver::new(p.USB, Irqs, p.PA12, p.PA11);
+        let mut config = embassy_usb::Config::new(0xc0de, 0xcafe);
+        config.manufacturer = Some("Embassy");
+        config.product = Some("USB-DFU Bootloader example");
+        config.serial_number = Some("1235678");
+
+        let fw_config = FirmwareUpdaterConfig::from_linkerfile_blocking(&flash);
+        let mut buffer = AlignedBuffer([0; WRITE_SIZE]);
+        let updater = BlockingFirmwareUpdater::new(fw_config, &mut buffer.0[..]);
+
+        let mut device_descriptor = [0; 256];
+        let mut config_descriptor = [0; 256];
+        let mut bos_descriptor = [0; 256];
+        let mut control_buf = [0; 4096];
+        let mut state = Control::new(updater, DfuAttributes::CAN_DOWNLOAD);
+        let mut builder = Builder::new(
+            driver,
+            config,
+            &mut device_descriptor,
+            &mut config_descriptor,
+            &mut bos_descriptor,
+            &mut [],
+            &mut control_buf,
+        );
+
+        usb_dfu::<_, _, _, ResetImmediate, 4096>(&mut builder, &mut state);
+
+        let mut dev = builder.build();
+        embassy_futures::block_on(dev.run());
+    }
+
+    unsafe { bl.load(BANK1_REGION.base + active_offset) }
+}
+
+#[no_mangle]
+#[cfg_attr(target_os = "none", link_section = ".HardFault.user")]
+unsafe extern "C" fn HardFault() {
+    cortex_m::peripheral::SCB::sys_reset();
+}
+
+#[exception]
+unsafe fn DefaultHandler(_: i16) -> ! {
+    const SCB_ICSR: *const u32 = 0xE000_ED04 as *const u32;
+    let irqn = core::ptr::read_volatile(SCB_ICSR) as u8 as i16 - 16;
+
+    panic!("DefaultHandler #{:?}", irqn);
+}
+
+#[panic_handler]
+fn panic(_info: &core::panic::PanicInfo) -> ! {
+    cortex_m::asm::udf();
+}