embassy/embassy-usb-dfu/src/application.rs

136 lines
4.6 KiB
Rust

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);
}