Abstract chip reset logic, add Reset impls for cortex-m and esp32c3

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()
+    }
+}