4 files changed, 58 insertions, 14 deletions

diff --git a/embassy-usb-dfu/Cargo.toml b/embassy-usb-dfu/Cargo.toml
index 62398afbc..02146c646 100644
--- a/embassy-usb-dfu/Cargo.toml
+++ b/embassy-usb-dfu/Cargo.toml
@@ -15,15 +15,16 @@ categories = [
 
 [dependencies]
 bitflags = "2.4.1"
-cortex-m = { version = "0.7.7", features = ["inline-asm"] }
+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-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]
 bootloader = []
diff --git a/embassy-usb-dfu/src/application.rs b/embassy-usb-dfu/src/application.rs
index 5ff8f90f8..75689db26 100644
--- a/embassy-usb-dfu/src/application.rs
+++ b/embassy-usb-dfu/src/application.rs
@@ -1,3 +1,5 @@
+use core::marker::PhantomData;
+
 use embassy_boot::BlockingFirmwareState;
 use embassy_time::{Duration, Instant};
 use embassy_usb::control::{InResponse, OutResponse, Recipient, RequestType};
@@ -9,17 +11,19 @@ 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> {
+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> Control<'d, STATE> {
+impl<'d, STATE: NorFlash, RST: Reset> Control<'d, STATE, RST> {
     pub fn new(firmware_state: BlockingFirmwareState<'d, STATE>, attrs: DfuAttributes) -> Self {
         Control {
             firmware_state,
@@ -27,11 +31,12 @@ impl<'d, STATE: NorFlash> Control<'d, STATE> {
             state: State::AppIdle,
             detach_start: None,
             timeout: None,
+            _rst: PhantomData,
         }
     }
 }
 
-impl<'d, STATE: NorFlash> Handler for Control<'d, STATE> {
+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;
@@ -45,7 +50,7 @@ impl<'d, STATE: NorFlash> Handler for Control<'d, STATE> {
                 self.firmware_state
                     .mark_dfu()
                     .expect("Failed to mark DFU mode in bootloader");
-                cortex_m::peripheral::SCB::sys_reset();
+                RST::sys_reset()
             }
         }
     }
@@ -103,9 +108,9 @@ impl<'d, STATE: NorFlash> Handler for Control<'d, STATE> {
 /// 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>(
+pub fn usb_dfu<'d, D: Driver<'d>, STATE: NorFlash, RST: Reset>(
     builder: &mut Builder<'d, D>,
-    handler: &'d mut Control<'d, STATE>,
+    handler: &'d mut Control<'d, STATE, RST>,
     timeout: Duration,
 ) {
     let mut func = builder.function(0x00, 0x00, 0x00);
diff --git a/embassy-usb-dfu/src/bootloader.rs b/embassy-usb-dfu/src/bootloader.rs
index 99384d961..d41e6280d 100644
--- a/embassy-usb-dfu/src/bootloader.rs
+++ b/embassy-usb-dfu/src/bootloader.rs
@@ -1,3 +1,5 @@
+use core::marker::PhantomData;
+
 use embassy_boot::{AlignedBuffer, BlockingFirmwareUpdater};
 use embassy_usb::control::{InResponse, OutResponse, Recipient, RequestType};
 use embassy_usb::driver::Driver;
@@ -8,17 +10,19 @@ 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, const BLOCK_SIZE: usize> {
+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, const BLOCK_SIZE: usize> Control<'d, DFU, STATE, BLOCK_SIZE> {
+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,
@@ -26,6 +30,7 @@ impl<'d, DFU: NorFlash, STATE: NorFlash, const BLOCK_SIZE: usize> Control<'d, DF
             state: State::DfuIdle,
             status: Status::Ok,
             offset: 0,
+            _rst: PhantomData,
         }
     }
 
@@ -36,7 +41,9 @@ impl<'d, DFU: NorFlash, STATE: NorFlash, const BLOCK_SIZE: usize> Control<'d, DF
     }
 }
 
-impl<'d, DFU: NorFlash, STATE: NorFlash, const BLOCK_SIZE: usize> Handler for Control<'d, DFU, STATE, BLOCK_SIZE> {
+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,
@@ -131,7 +138,7 @@ impl<'d, DFU: NorFlash, STATE: NorFlash, const BLOCK_SIZE: usize> Handler for Co
                 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 => cortex_m::peripheral::SCB::sys_reset(),
+                    State::ManifestSync => RST::sys_reset(),
                     _ => {}
                 }
 
@@ -157,9 +164,9 @@ impl<'d, DFU: NorFlash, STATE: NorFlash, const BLOCK_SIZE: usize> Handler for Co
 ///
 /// 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, const BLOCK_SIZE: usize>(
+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, BLOCK_SIZE>,
+    handler: &'d mut Control<'d, DFU, STATE, RST, BLOCK_SIZE>,
 ) {
     let mut func = builder.function(0x00, 0x00, 0x00);
     let mut iface = func.interface();
diff --git a/embassy-usb-dfu/src/lib.rs b/embassy-usb-dfu/src/lib.rs
index ae0fbbd4c..283905de9 100644
--- a/embassy-usb-dfu/src/lib.rs
+++ b/embassy-usb-dfu/src/lib.rs
@@ -18,3 +18,34 @@ pub use self::application::*;
     not(any(feature = "bootloader", 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()
+    }
+}