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//! A crate for talking to J-Link debug probes connected via USB. //! //! This crate allows access to the vendor-specific USB interface used to control JTAG / SWD //! operations and other functionality. It does *not* provide access to the virtual COM port //! functionality (which is a regular CDC device, so no special support is needed). //! //! Inspired by [libjaylink] (though this library is not a port). //! //! [libjaylink]: https://repo.or.cz/libjaylink.git //! //! # Pinout //! //! J-Link uses a pinout based on the standard 20-pin ARM JTAG connector, extended for SWD //! compatibility and with pins for UART. //! //! JTAG pinout: //! //! ```notrust //! ┌───────────┐ //! VTref │ * 1 2 * │ NC //! nTRST │ * 3 4 * │ GND //! TDI │ * 5 6 * │ GND //! TMS │ * 7 8 * │ GND //! TCK ┌┘ * 9 10 * │ GND //! RTCK └┐ * 11 12 * │ GND //! TDO │ * 13 14 * │ GND //! RESET │ * 15 16 * │ GND //! DBGRQ │ * 17 18 * │ GND //! 5V-Supply │ * 19 20 * │ GND //! └───────────┘ //! ``` //! //! SWD (+ UART) pinout: //! //! ```notrust //! ┌───────────┐ //! VTref │ * 1 2 * │ NC //! - │ * 3 4 * │ GND //! J-Link TX │ * 5 6 * │ GND //! SWDIO │ * 7 8 * │ GND //! SWCLK ┌┘ * 9 10 * │ GND //! - └┐ * 11 12 * │ GND //! SWO │ * 13 14 * │ GND //! RESET │ * 15 16 * │ GND //! J-Link RX │ * 17 18 * │ GND //! 5V-Supply │ * 19 20 * │ GND //! └───────────┘ //! ``` //! //! # Reference //! //! Segger has released a PDF documenting the USB protocol: "Reference manual for J-Link USB //! Protocol" (Document RM08001-R2). //! //! The archive.org version is the most up-to-date one. #![doc(html_root_url = "https://docs.rs/jaylink/0.1.0")] // Deny a few warnings in doctests, since rustdoc `allow`s many warnings by default #![doc(test(attr(deny(unused_imports, unused_must_use))))] #![warn(missing_debug_implementations, rust_2018_idioms)] mod bits; mod capabilities; mod error; mod readme; mod private { /// Used in `__NonExhaustive` variants to make them unconstructible. /// /// Users are still able to match on them, unfortunately. #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)] pub enum Private {} } pub use self::bits::BitIter; pub use self::capabilities::Capabilities; pub use self::error::{Error, ErrorKind}; use self::bits::IteratorExt as _; use self::error::ResultExt as _; use bitflags::bitflags; use byteorder::{LittleEndian, ReadBytesExt}; use log::{debug, trace, warn}; use std::cell::{Cell, RefCell, RefMut}; use std::sync::atomic::{AtomicBool, Ordering}; use std::time::Duration; use std::{cmp, fmt}; /// A result type with the error hardwired to [`Error`]. /// /// [`Error`]: struct.Error.html pub type Result<T> = std::result::Result<T, Error>; const VID_SEGGER: u16 = 0x1366; const TIMEOUT_DEFAULT: Duration = Duration::from_millis(500); #[repr(u8)] #[allow(dead_code)] enum Command { Version = 0x01, GetSpeeds = 0xC0, GetMaxMemBlock = 0xD4, GetCaps = 0xE8, GetCapsEx = 0xED, GetHwVersion = 0xF0, GetState = 0x07, GetHwInfo = 0xC1, GetCounters = 0xC2, MeasureRtckReact = 0xF6, ResetTrst = 0x02, SetSpeed = 0x05, SelectIf = 0xC7, SetKsPower = 0x08, HwClock = 0xC8, HwTms0 = 0xC9, HwTms1 = 0xCA, HwData0 = 0xCB, HwData1 = 0xCC, HwJtag = 0xCD, HwJtag2 = 0xCE, HwJtag3 = 0xCF, HwJtagWrite = 0xD5, HwJtagGetResult = 0xD6, HwTrst0 = 0xDE, HwTrst1 = 0xDF, WriteDcc = 0xF1, ResetTarget = 0x03, HwReleaseResetStopEx = 0xD0, HwReleaseResetStopTimed = 0xD1, HwReset0 = 0xDC, HwReset1 = 0xDD, GetCpuCaps = 0xE9, ExecCpuCmd = 0xEA, WriteMem = 0xF4, ReadMem = 0xF5, WriteMemArm79 = 0xF7, ReadMemArm79 = 0xF8, ReadConfig = 0xF2, WriteConfig = 0xF3, } /// A handle to a J-Link USB device. /// /// This is the main interface type of this library. There are multiple ways of obtaining an /// instance of it: /// /// * [`JayLink::open_by_serial`]: Either opens the only J-Link device connected to the computer, or /// opens a specific one by its serial number. Recommended for applications that interact with one /// J-Link device only (ie. most of them). /// * [`JayLink::open_usb`]: Opens a specific J-Link device according to the given /// [`UsbDeviceInfo`]. Also see [`scan_usb`]. /// /// [`JayLink::open_by_serial`]: struct.JayLink.html#method.open_by_serial /// [`JayLink::open_usb`]: struct.JayLink.html#method.open_usb /// [`UsbDeviceInfo`]: struct.UsbDeviceInfo.html /// [`scan_usb`]: fn.scan_usb.html pub struct JayLink { handle: rusb::DeviceHandle<rusb::GlobalContext>, read_ep: u8, write_ep: u8, cmd_buf: RefCell<Vec<u8>>, /// The capabilities reported by the device. They're fetched lazily and are globally cached /// since they don't change while connected to the device (hopefully!). caps: Cell<Option<Capabilities>>, /// The currently selected target interface. This is cached to avoid unnecessary roundtrips when /// performing JTAG/SWD operations. interface: Cell<Option<Interface>>, /// The configured interface speed. This is stored here when the user sets it. Switching /// interfaces will revert to the default speed, in which case this library restores the speed /// stored here. speed: Cell<Option<CommunicationSpeed>>, manufacturer: String, product: String, serial: String, } impl JayLink { /// Opens an attached J-Link device by its serial number. /// /// If `serial` is `None`, this will open the only attached J-Link device, and return an error /// of type [`MultipleDevicesFound`] when more than one is attached. This is usually the desired /// behavior of robust applications. /// /// [`MultipleDevicesFound`]: enum.ErrorKind.html#variant.MultipleDevicesFound pub fn open_by_serial(serial: Option<&str>) -> Result<Self> { let mut devices = scan_usb()?.filter_map(|usb_device| { let dev = match usb_device.open() { Ok(dev) => dev, Err(_) => return None, }; if let Some(serial) = serial { if dev.serial_string() == serial { Some(dev) } else { None } } else { Some(dev) } }); let first = devices.next().ok_or_else(|| { let message = if let Some(serial ) = serial { format!("no J-Link device with serial {} was found (make sure your current user has permissions to access it)", serial) } else { "no J-Link devices found (make sure your current user has permissions to access them)".to_string() }; Error::new(ErrorKind::DeviceNotFound, message) })?; if devices.next().is_some() { let msg = if let Some(serial) = serial { format!("found multiple devices matching serial {}", serial) } else { "multiple devices found (specify serial number to select one)".to_string() }; return Err(Error::new(ErrorKind::MultipleDevicesFound, msg)); } Ok(first) } /// Opens a specific J-Link USB device. pub fn open_usb(usb_device: UsbDeviceInfo) -> Result<Self> { // NB: We take `UsbDeviceInfo` by value since it isn't cloneable (yet), so taking it by-ref // would lock us into a less flexible API. It should be easy to make it cloneable with a few // changes to rusb though. let descr = usb_device .inner .device_descriptor() .expect("libusb_get_device_descriptor returned unexpected error"); let mut handle = usb_device .inner .open() .jaylink_err_while("opening USB device")?; debug!("open_usb: device descriptor: {:#x?}", descr); if descr.num_configurations() != 1 { warn!( "device has {} configurations, expected 1", descr.num_configurations() ); } let conf = handle .active_configuration() .jaylink_err_while("reading device configuration")?; // Device configurations are 1-indexed, apparently if conf != 1 { warn!( "device in configuration {}, expected 1; changing configuration", conf ); handle.set_active_configuration(1).jaylink_err()?; } let conf = usb_device .inner .active_config_descriptor() .jaylink_err_while("reading device configuration descriptor")?; debug!("scanning {} interfaces", conf.num_interfaces()); trace!("active configuration descriptor: {:#x?}", conf); let mut jlink_intf = None; for (i, intf) in conf.interfaces().enumerate() { trace!("interface #{} descriptors:", i + 1); for descr in intf.descriptors() { trace!("{:#x?}", descr); // We detect the proprietary J-Link interface using the vendor-specific class codes // and the endpoint properties if descr.class_code() == 0xff && descr.sub_class_code() == 0xff && descr.protocol_code() == 0xff { if let Some((intf, _, _)) = jlink_intf { return Err(format!( "found multiple matching USB interfaces ({} and {})", intf, descr.interface_number() )) .jaylink_err(); } let endpoints: Vec<_> = descr.endpoint_descriptors().collect(); trace!("endpoint descriptors: {:#x?}", endpoints); if endpoints.len() != 2 { warn!("vendor-specific interface with {} endpoints, expected 2 (skipping interface)", endpoints.len()); continue; } if !endpoints .iter() .all(|ep| ep.transfer_type() == rusb::TransferType::Bulk) { warn!( "encountered non-bulk endpoints, skipping interface: {:#x?}", endpoints ); continue; } let (read_ep, write_ep) = if endpoints[0].direction() == rusb::Direction::In { (endpoints[0].address(), endpoints[1].address()) } else { (endpoints[1].address(), endpoints[0].address()) }; jlink_intf = Some((descr.interface_number(), read_ep, write_ep)); debug!("J-Link interface is #{}", descr.interface_number()); } } } let (intf, read_ep, write_ep) = if let Some(intf) = jlink_intf { intf } else { return Err("device is not a J-Link device".to_string()).jaylink_err(); }; handle .claim_interface(intf) .jaylink_err_while("taking control over USB device")?; // Check that we're still in the expected configuration (another application could // interfere). // See: http://libusb.sourceforge.net/api-1.0/caveats.html let conf = handle.active_configuration().jaylink_err()?; if conf != 1 { return Err("another application is accessing the device".to_string()).jaylink_err(); } Ok(Self { manufacturer: handle .read_manufacturer_string_ascii(&descr) .jaylink_err()?, product: handle.read_product_string_ascii(&descr).jaylink_err()?, serial: handle .read_serial_number_string_ascii(&descr) .jaylink_err()?, read_ep, write_ep, cmd_buf: RefCell::new(Vec::new()), caps: Cell::new(None), interface: Cell::new(None), speed: Cell::new(None), handle, }) } /// Returns the manufacturer string stored in the device descriptor. pub fn manufacturer_string(&self) -> &str { &self.manufacturer } /// Returns the product string stored in the device descriptor. pub fn product_string(&self) -> &str { &self.product } /// Returns the serial number string stored in the device descriptor. /// /// This serial number string can be passed to [`JayLink::open_by_serial`] to open a specific /// J-Link device. /// /// [`JayLink::open_by_serial`]: #method.open_by_serial pub fn serial_string(&self) -> &str { &self.serial } fn buf(&self, len: usize) -> RefMut<'_, Vec<u8>> { let mut vec = self.cmd_buf.borrow_mut(); vec.resize(len, 0); vec } fn write_cmd(&self, cmd: &[u8]) -> Result<()> { trace!("write {} bytes: {:x?}", cmd.len(), cmd); let bytes = self .handle .write_bulk(self.write_ep, cmd, TIMEOUT_DEFAULT) .jaylink_err_while("writing data to device")?; if bytes != cmd.len() { return Err(format!( "incomplete write (expected {} bytes, wrote {})", cmd.len(), bytes )) .jaylink_err(); } Ok(()) } fn read(&self, buf: &mut [u8]) -> Result<()> { let mut total = 0; while total < buf.len() { let buf = &mut buf[total..]; let bytes = self .handle .read_bulk(self.read_ep, buf, TIMEOUT_DEFAULT) .jaylink_err_while("reading from device")?; total += bytes; } trace!("read {} bytes: {:x?}", buf.len(), buf); Ok(()) } fn require_capabilities(&self, cap: Capabilities) -> Result<()> { let caps = self.read_capabilities()?; if caps.contains(cap) { Ok(()) } else { Err(Error::new( ErrorKind::MissingCapability, format!("device is missing capabilities ({:?}) for operation", cap), )) } } fn has_capabilities(&self, cap: Capabilities) -> Result<bool> { let caps = self.read_capabilities()?; Ok(caps.contains(cap)) } /// Reads the firmware version string from the device. pub fn read_firmware_version(&self) -> Result<String> { self.write_cmd(&[Command::Version as u8])?; let mut buf = [0; 2]; self.read(&mut buf)?; let num_bytes = u16::from_le_bytes(buf); let mut buf = self.buf(num_bytes.into()); let mut buf = &mut buf[..usize::from(num_bytes)]; self.read(&mut buf)?; Ok(String::from_utf8_lossy(buf).to_string()) } /// Reads the hardware version from the device. /// /// This requires the [`GET_HW_VERSION`] capability. /// /// [`GET_HW_VERSION`]: struct.Capabilities.html#associatedconstant.GET_HW_VERSION pub fn read_hardware_version(&self) -> Result<HardwareVersion> { self.require_capabilities(Capabilities::GET_HW_VERSION)?; self.write_cmd(&[Command::GetHwVersion as u8])?; let mut buf = [0; 4]; self.read(&mut buf)?; Ok(HardwareVersion::from_u32(u32::from_le_bytes(buf))) } /// Read the probe's CPU speed information. /// /// This requires the [`SPEED_INFO`] capability. /// /// [`SPEED_INFO`]: struct.Capabilities.html#associatedconstant.SPEED_INFO pub fn read_speeds(&self) -> Result<Speeds> { self.require_capabilities(Capabilities::SPEED_INFO)?; self.write_cmd(&[Command::GetSpeeds as u8])?; let mut buf = [0; 6]; self.read(&mut buf)?; let mut buf = &buf[..]; Ok(Speeds { base_freq: buf.read_u32::<LittleEndian>().unwrap(), min_div: buf.read_u16::<LittleEndian>().unwrap(), }) } /// Reads the maximum mem block size in Bytes. /// /// This requires the [`GET_MAX_BLOCK_SIZE`] capability. /// /// [`GET_MAX_BLOCK_SIZE`]: struct.Capabilities.html#associatedconstant.GET_MAX_BLOCK_SIZE pub fn read_max_mem_block(&self) -> Result<u32> { // This cap refers to a nonexistent command `GET_MAX_BLOCK_SIZE`, but it probably means // `GET_MAX_MEM_BLOCK`. self.require_capabilities(Capabilities::GET_MAX_BLOCK_SIZE)?; self.write_cmd(&[Command::GetMaxMemBlock as u8])?; let mut buf = [0; 4]; self.read(&mut buf)?; Ok(u32::from_le_bytes(buf)) } /// Reads the advertised capabilities from the device. pub fn read_capabilities(&self) -> Result<Capabilities> { if let Some(caps) = self.caps.get() { Ok(caps) } else { self.write_cmd(&[Command::GetCaps as u8])?; let mut buf = [0; 4]; self.read(&mut buf)?; let mut caps = Capabilities::from_raw_legacy(u32::from_le_bytes(buf)); debug!("legacy caps: {:?}", caps); // If the `GET_CAPS_EX` capability is set, use the extended capability command to fetch // all the capabilities. if caps.contains(Capabilities::GET_CAPS_EX) { self.write_cmd(&[Command::GetCapsEx as u8])?; let mut buf = [0; 32]; self.read(&mut buf)?; let real_caps = Capabilities::from_raw_ex(buf); if !real_caps.contains(caps) { return Err(format!( "ext. caps are not a superset of legacy caps (legacy: {:?}, ex: {:?})", caps, real_caps )) .jaylink_err(); } debug!("extended caps: {:?}", real_caps); caps = real_caps; } else { debug!("extended caps not supported"); } self.caps.set(Some(caps)); Ok(caps) } } /// Changes the state of the TMS / SWDIO pin (pin 7). /// /// The pin will be set to the level of `VTref` if `tms` is `true`, and to GND if it is `false`. /// /// **Note**: On some hardware, detaching `VTref` might not affect the internal reading, so the /// old level might still be used afterwards. pub fn set_tms(&mut self, tms: bool) -> Result<()> { let cmd = if tms { Command::HwTms1 } else { Command::HwTms0 }; self.write_cmd(&[cmd as u8]) } /// Changes the state of the TDI / TX pin (pin 5). /// /// The pin will be set to the level of `VTref` if `tdi` is `true`, and to GND if it is `false`. /// /// **Note**: On some hardware, detaching `VTref` might not affect the internal reading, so the /// old level might still be used afterwards. pub fn set_tdi(&mut self, tdi: bool) -> Result<()> { let cmd = if tdi { Command::HwData1 } else { Command::HwData0 }; self.write_cmd(&[cmd as u8]) } /// Changes the state of the (n)TRST pin (pin 3). /// /// The pin will be set to the level of `VTref` if `trst` is `true`, and to GND if it is /// `false`. /// /// **Note**: On some hardware, detaching `VTref` might not affect the internal reading, so the /// old level might still be used afterwards. /// /// **Note**: Some embedded J-Link probes may not expose this pin or may not allow controlling /// it using this function. pub fn set_trst(&mut self, trst: bool) -> Result<()> { let cmd = if trst { Command::HwTrst1 } else { Command::HwTrst0 }; self.write_cmd(&[cmd as u8]) } /// Changes the state of the RESET pin (pin 15). /// /// RESET is an open-collector / open-drain output. If `reset` is `true`, the output will float. /// If `reset` is `false`, the output will be pulled to ground. /// /// **Note**: Some embedded J-Link probes may not expose this pin or may not allow controlling /// it using this function. pub fn set_reset(&mut self, reset: bool) -> Result<()> { let cmd = if reset { Command::HwReset1 } else { Command::HwReset0 }; self.write_cmd(&[cmd as u8]) } /// Resets the target's JTAG TAP controller by temporarily asserting (n)TRST (Pin 3). pub fn reset_trst(&mut self) -> Result<()> { self.write_cmd(&[Command::ResetTrst as u8]) } /// Resets the target by temporarily asserting the RESET pin (pin 15). pub fn reset_target(&mut self) -> Result<()> { self.write_cmd(&[Command::ResetTarget as u8]) } /// Reads the currently selected target interface. /// /// This requires the [`SELECT_IF`] capability. /// /// **Note**: There is no guarantee that the returned interface is actually supported (ie. it /// might not be in the list returned by [`read_available_interfaces`]). In particular, some /// embedded J-Link probes start up with JTAG selected, but only support SWD. /// /// [`SELECT_IF`]: struct.Capabilities.html#associatedconstant.SELECT_IF /// [`read_available_interfaces`]: #method.read_available_interfaces pub fn read_current_interface(&self) -> Result<Interface> { if let Some(intf) = self.interface.get() { Ok(intf) } else { self.require_capabilities(Capabilities::SELECT_IF)?; self.write_cmd(&[Command::SelectIf as u8, 0xFE])?; let mut buf = [0; 4]; self.read(&mut buf)?; let raw = u32::from_le_bytes(buf); let intf = Interface::from_u32(raw) .ok_or_else(|| format!("invalid interface value {}", raw)) .jaylink_err()?; debug!("read active interface: {:?}", intf); self.interface.set(Some(intf)); Ok(intf) } } /// Reads the list of available target interfaces that can be selected. /// /// This requires the [`SELECT_IF`] capability. /// /// [`SELECT_IF`]: struct.Capabilities.html#associatedconstant.SELECT_IF pub fn read_available_interfaces(&self) -> Result<impl Iterator<Item = Interface>> { self.require_capabilities(Capabilities::SELECT_IF)?; self.write_cmd(&[Command::SelectIf as u8, 0xFF])?; let mut buf = [0; 4]; self.read(&mut buf)?; let intfs = Interfaces::from_bits_truncate(u32::from_le_bytes(buf)); Ok(intfs.into_iter()) } /// Selects the interface to use for talking to the target MCU. /// /// This requires the [`SELECT_IF`] capability. /// /// [`SELECT_IF`]: struct.Capabilities.html#associatedconstant.SELECT_IF pub fn select_interface(&mut self, intf: Interface) -> Result<()> { if self.interface.get() == Some(intf) { return Ok(()); } self.require_capabilities(Capabilities::SELECT_IF)?; self.write_cmd(&[Command::SelectIf as u8, intf.as_u8()])?; // Returns the previous interface, ignore it let mut buf = [0; 4]; self.read(&mut buf)?; self.interface.set(Some(intf)); if let Some(speed) = self.speed.get() { // Restore previously configured comm speed self.set_speed(speed)?; } Ok(()) } /// Sets the target communication speed. /// /// If `speed` is set to [`CommunicationSpeed::ADAPTIVE`], then the [`ADAPTIVE_CLOCKING`] /// capability is required. /// /// [`CommunicationSpeed::ADAPTIVE`]: struct.CommunicationSpeed.html#associatedconstant.ADAPTIVE /// [`ADAPTIVE_CLOCKING`]: struct.Capabilities.html#associatedconstant.ADAPTIVE_CLOCKING pub fn set_speed(&mut self, speed: CommunicationSpeed) -> Result<()> { if speed.raw == CommunicationSpeed::ADAPTIVE.raw { self.require_capabilities(Capabilities::ADAPTIVE_CLOCKING)?; } let mut buf = [Command::SetSpeed as u8, 0, 0]; buf[1..3].copy_from_slice(&speed.raw.to_le_bytes()); self.write_cmd(&buf)?; self.speed.set(Some(speed)); Ok(()) } /// Reads the target voltage measured on the `VTref` pin, in millivolts. pub fn read_target_voltage(&self) -> Result<u16> { self.write_cmd(&[Command::GetState as u8])?; let mut buf = [0; 8]; self.read(&mut buf)?; let voltage = [buf[0], buf[1]]; Ok(u16::from_le_bytes(voltage)) } /// Enable or disable the 5V Power supply on pin 19. /// /// This requires the [`SET_KS_POWER`] capability. /// /// **Note**: The startup state of the power supply can be configured in non-volatile memory. /// /// **Note**: Some embedded J-Links may not provide this feature or do not have the 5V supply /// routed to a pin. /// /// **Note**: The 5V supply is protected against overcurrent. Check the device manual for more /// information on this. /// /// [`SET_KS_POWER`]: struct.Capabilities.html#associatedconstant.SET_KS_POWER pub fn set_kickstart_power(&mut self, enable: bool) -> Result<()> { self.require_capabilities(Capabilities::SET_KS_POWER)?; self.write_cmd(&[Command::SetKsPower as u8, enable as u8])?; Ok(()) } /// Performs a JTAG I/O operation. /// /// This will shift out data on `TMS` (pin 7) and `TDI` (pin 5), while reading data shifted /// into `TDO` (pin 13). /// /// The data received on `TDO` is returned to the caller as an iterator yielding `bool`s. /// /// The probe will be put into JTAG interface mode, if JTAG isn't selected already. /// /// # Parameters /// /// * `tms`: TMS bits to transmit. /// * `tdi`: TDI bits to transmit. /// /// # Panics /// /// This method will panic if `tms` and `tdi` have different lengths. It will also panic if any /// of them contains more then 65535 bits of data, which is the maximum amount that can be /// transferred in one operation. // NB: Explicit `'a` lifetime used to improve rustdoc output pub fn jtag_io<'a, M, D>(&'a mut self, tms: M, tdi: D) -> Result<BitIter<'a>> where M: IntoIterator<Item = bool>, D: IntoIterator<Item = bool>, { // There's 3 commands for doing a JTAG transfer. The older 2 are obsolete with hardware // version 5 and above, which adds the 3rd command. Unfortunately we cannot reliably use the // HW version to determine this since some embedded J-Link probes have a HW version of // 1.0.0, but still support SWD, so we use the `SELECT_IF` capability instead. let cmd = if self.has_capabilities(Capabilities::SELECT_IF)? { // Use the new JTAG3 command, make sure to select the JTAG interface mode self.select_interface(Interface::Jtag)?; Command::HwJtag3 } else { // Use the legacy JTAG2 command // FIXME is HW_JTAG relevant at all? Command::HwJtag2 }; // Collect the bit iterators into the buffer. We don't know the length in advance. let tms = tms.into_iter(); let tdi = tdi.into_iter(); let bit_count_hint = cmp::max(tms.size_hint().0, tdi.size_hint().0); let capacity = 1 + 1 + 2 + (bit_count_hint + 7 / 8) * 2; let mut buf = self.buf(capacity); buf.resize(4, 0); buf[0] = cmd as u8; // buf[1] is dummy data for alignment // buf[2..=3] is the bit count, which we'll fill in later buf.extend(tms.collapse_bytes()); let tms_bit_count = buf.len() - 4; buf.extend(tdi.collapse_bytes()); let tdi_bit_count = buf.len() - 4 - tms_bit_count; assert_eq!( tms_bit_count, tdi_bit_count, "TMS and TDI must have the same number of bits" ); assert!(tms_bit_count < 65535, "too much data to transfer"); // JTAG3 and JTAG2 use the same format for JTAG operations let num_bits = tms_bit_count as u16; buf[2..=3].copy_from_slice(&num_bits.to_le_bytes()); let num_bytes = usize::from((num_bits + 7) >> 3); self.write_cmd(&buf)?; // Response is `num_bytes` TDO data bytes and one status byte self.read(&mut buf[..num_bytes + 1])?; if buf[num_bytes] != 0 { return Err(format!("SWD op returned error code {:#x}", buf[num_bytes])).jaylink_err(); } drop(buf); Ok(BitIter::new( &self.cmd_buf.get_mut()[..num_bytes], tms_bit_count, )) } /// Performs an SWD I/O operation. /// /// This will put the probe in SWD mode if it isn't already in that mode. /// /// This requires the [`SELECT_IF`] capability. /// /// # Parameters /// /// * `dir`: Transfer directions of the `swdio` bits (`false` = 0 = Input, `true` = 1 = Output). /// * `swdio`: SWD data bits. /// /// If `dir` is `true`, the corresponding bit in `swdio` will be written to the target; if it is /// `false`, the bit in `swdio` is ignored and a bit is read from the target instead. /// /// # Return Value /// /// An iterator over the `SWDIO` bits is returned. Bits that were sent to the target (where /// `dir` = `true`) are undefined, and bits that were read from the target (`dir` = `false`) /// will have whatever value the target sent. /// /// [`SELECT_IF`]: struct.Capabilities.html#associatedconstant.SELECT_IF // NB: Explicit `'a` lifetime used to improve rustdoc output pub fn swd_io<'a, D, S>(&'a mut self, dir: D, swdio: S) -> Result<BitIter<'a>> where D: IntoIterator<Item = bool>, S: IntoIterator<Item = bool>, { self.select_interface(Interface::Swd)?; // Collect the bit iterators into the buffer. We don't know the length in advance. let dir = dir.into_iter(); let swdio = swdio.into_iter(); let bit_count_hint = cmp::max(dir.size_hint().0, swdio.size_hint().0); let capacity = 1 + 1 + 2 + (bit_count_hint + 7 / 8) * 2; let mut buf = self.buf(capacity); buf.resize(4, 0); buf[0] = Command::HwJtag3 as u8; buf[1] = 0; // buf[1] is dummy data for alignment // buf[2..=3] is the bit count, which we'll fill in later let mut dir_bit_count = 0; buf.extend(dir.inspect(|_| dir_bit_count += 1).collapse_bytes()); let mut swdio_bit_count = 0; buf.extend(swdio.inspect(|_| swdio_bit_count += 1).collapse_bytes()); assert_eq!( dir_bit_count, swdio_bit_count, "DIR and SWDIO must have the same number of bits" ); assert!(dir_bit_count < 65535, "too much data to transfer"); let num_bits = dir_bit_count as u16; buf[2..=3].copy_from_slice(&num_bits.to_le_bytes()); let num_bytes = usize::from((num_bits + 7) >> 3); self.write_cmd(&buf)?; // Response is `num_bytes` SWDIO data bytes and one status byte self.read(&mut buf[..num_bytes + 1])?; if buf[num_bytes] != 0 { return Err(format!("SWD op returned error code {:#x}", buf[num_bytes])).jaylink_err(); } drop(buf); Ok(BitIter::new( &self.cmd_buf.get_mut()[..num_bytes], dir_bit_count, )) } } impl fmt::Debug for JayLink { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { f.debug_struct("JayLink") .field("manufacturer", &self.manufacturer) .field("product", &self.product) .field("serial", &self.serial) .finish() } } /// Target communication speed setting. /// /// This determines the clock frequency of the JTAG/SWD communication. #[derive(Debug, Copy, Clone)] pub struct CommunicationSpeed { raw: u16, } impl CommunicationSpeed { /// Let the J-Link probe decide the speed. /// /// Requires the [`ADAPTIVE_CLOCKING`] capability. /// /// [`ADAPTIVE_CLOCKING`]: struct.Capabilities.html#associatedconstant.ADAPTIVE_CLOCKING pub const ADAPTIVE: Self = Self { raw: 0xFFFF }; /// Manually specify speed in kHz. /// /// Returns `None` if the value is the invalid value `0xFFFF`. Note that this doesn't mean that /// every other value will be accepted by the device. pub fn khz(khz: u16) -> Option<Self> { if khz == 0xFFFF { None } else { Some(Self { raw: khz }) } } } /// List of target interfaces (JTAG / SWD). #[derive(Debug, Copy, Clone, PartialEq, Eq)] pub enum Interface { /// JTAG interface. Jtag, /// SWD interface (Serial Wire Debug). Swd, #[doc(hidden)] __NonExhaustive(private::Private), } impl Interface { fn from_u32(raw: u32) -> Option<Self> { match raw { 0 => Some(Interface::Jtag), 1 => Some(Interface::Swd), _ => None, } } fn as_u8(self) -> u8 { match self { Interface::Jtag => 0, Interface::Swd => 1, Interface::__NonExhaustive(_) => unreachable!(), } } } impl fmt::Display for Interface { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { match self { Interface::Jtag => f.write_str("JTAG"), Interface::Swd => f.write_str("SWD"), Interface::__NonExhaustive(_) => unreachable!(), } } } bitflags! { /// Bitset of supported target interfaces. pub struct Interfaces: u32 { /// JTAG interface. const JTAG = (1 << 0); /// SWD interface (Serial Wire Debug). const SWD = (1 << 1); } } impl Interfaces { /// Returns an iterator over all [`Interface`]s in this bitset. /// /// [`Interface`]: enum.Interface.html pub fn into_iter(self) -> impl Iterator<Item = Interface> { [(Self::JTAG, Interface::Jtag), (Self::SWD, Interface::Swd)] .iter() .filter(move |(flag, _)| self.contains(*flag)) .map(|(_, intf)| *intf) } } /// A hardware version returned by [`JayLink::read_hardware_version`]. /// /// Note that the reported hardware version does not allow reliable feature detection, since /// embedded J-Link probes might return a hardware version of 1.0.0 despite supporting SWD and other /// much newer features. /// /// [`JayLink::read_hardware_version`]: struct.JayLink.html#method.read_hardware_version #[derive(Debug)] pub struct HardwareVersion(u32); impl HardwareVersion { fn from_u32(raw: u32) -> Self { HardwareVersion(raw) } /// Returns the type of hardware (or `None` if the hardware type is unknown). pub fn hardware_type(&self) -> Option<HardwareType> { Some(match (self.0 / 1000000) % 100 { 0 => HardwareType::JLink, 1 => HardwareType::JTrace, 2 => HardwareType::Flasher, 3 => HardwareType::JLinkPro, _ => return None, }) } /// The major version. pub fn major(&self) -> u8 { // Decimal coded Decimal, cool cool (self.0 / 10000) as u8 } /// The minor version. pub fn minor(&self) -> u8 { ((self.0 % 10000) / 100) as u8 } /// The hardware revision. pub fn revision(&self) -> u8 { (self.0 % 100) as u8 } } impl fmt::Display for HardwareVersion { fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { if let Some(hw) = self.hardware_type() { write!(f, "{:?} ", hw)?; } write!(f, "{}.{}.{}", self.major(), self.minor(), self.revision()) } } /// The hardware/product type of the device. #[derive(Copy, Clone, Debug, PartialEq, Eq)] pub enum HardwareType { JLink, JTrace, Flasher, JLinkPro, #[doc(hidden)] __NonExhaustive(private::Private), } /// J-Link CPU frequency info. #[derive(Debug)] pub struct Speeds { base_freq: u32, min_div: u16, } impl Speeds { pub fn base_freq(&self) -> u32 { self.base_freq } pub fn min_div(&self) -> u16 { self.min_div } } /// Generic info about a USB device. /// /// Returned by [`scan_usb`]. /// /// [`scan_usb`]: fn.scan_usb.html #[derive(Debug)] pub struct UsbDeviceInfo { inner: rusb::Device<rusb::GlobalContext>, vid: u16, pid: u16, } impl UsbDeviceInfo { /// Returns the vendor ID. /// /// Vendor IDs are centrally registered and can be looked up for example at /// [http://www.linux-usb.org/usb.ids](http://www.linux-usb.org/usb.ids). pub fn vid(&self) -> u16 { self.vid } /// Returns the product ID. pub fn pid(&self) -> u16 { self.pid } /// Returns the bus this device is attached to. pub fn bus_number(&self) -> u8 { self.inner.bus_number() } /// Returns the device address on the bus it's attached to. pub fn address(&self) -> u8 { self.inner.address() } /// Returns the port the device is attached to. pub fn port_number(&self) -> u8 { self.inner.port_number() } /// Tries to open this USB device. /// /// If successful, returns a [`JayLink`] instance. /// /// This method is equivalent to [`JayLink::open_usb`]. /// /// [`JayLink`]: struct.JayLink.html /// [`JayLink::open_usb`]: struct.JayLink.html#method.open_usb pub fn open(self) -> Result<JayLink> { JayLink::open_usb(self) } } /// Scans for J-Link USB devices. /// /// The returned iterator will yield all devices made by Segger, without filtering the product ID. pub fn scan_usb() -> Result<impl Iterator<Item = UsbDeviceInfo>> { log_libusb_info(); Ok(rusb::devices() .jaylink_err()? .iter() .filter_map(|dev| { // This calls `libusb_get_device_descriptor`, which should be unable to fail in any // libusb version (it only accesses cached descriptor data). let descr = dev .device_descriptor() .expect("libusb_get_device_descriptor returned unexpected error"); if descr.vendor_id() == VID_SEGGER { Some(UsbDeviceInfo { vid: descr.vendor_id(), pid: descr.product_id(), inner: dev, }) } else { None } }) .collect::<Vec<_>>() .into_iter()) } fn log_libusb_info() { static DID_LOG: AtomicBool = AtomicBool::new(false); if DID_LOG.swap(true, Ordering::Acquire) { return; } let vers = rusb::version(); debug!( "libusb {}.{}.{}.{}{}", vers.major(), vers.minor(), vers.micro(), vers.nano(), vers.rc() .map(|rc| format!("-{}", rc)) .unwrap_or(String::new()) ); debug!("libusb has capability API: {:?}", rusb::has_capability()); debug!("libusb has HID access: {:?}", rusb::has_hid_access()); debug!("libusb has hotplug support: {:?}", rusb::has_hotplug()); debug!( "libusb can detach kernel driver: {:?}", rusb::supports_detach_kernel_driver() ); }