probe-rs 0.31.0

A collection of on chip debugging tools to communicate with microchips.
Documentation
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
use super::CmsisDapDevice;
use crate::probe::{
    BoxedProbeError, DebugProbeInfo, DebugProbeSelector, ProbeCreationError,
    cmsisdap::{CmsisDapFactory, commands::CmsisDapError, commands::DEFAULT_USB_TIMEOUT},
};
#[cfg(feature = "cmsisdap_v1")]
use hidapi::HidApi;
use nusb::{DeviceInfo, MaybeFuture, descriptors::TransferType, transfer::Direction};

const USB_CLASS_HID: u8 = 0x03;
const USB_CMSIS_DAP_CLASS: u8 = 0xFF;
const USB_CMSIS_DAP_SUBCLASS: u8 = 0;

/// Finds all CMSIS-DAP devices, either v1 (HID) or v2 (WinUSB Bulk).
///
/// This method uses nusb to read device strings, which might fail due
/// to permission or driver errors, so it falls back to listing only
/// HID devices if it does not find any suitable devices.
#[tracing::instrument(skip_all)]
pub fn list_cmsisdap_devices() -> Vec<DebugProbeInfo> {
    tracing::debug!("Searching for CMSIS-DAP probes using nusb");

    #[cfg_attr(not(feature = "cmsisdap_v1"), expect(unused_mut))]
    let mut probes = match nusb::list_devices().wait() {
        Ok(devices) => devices
            .flat_map(|device| get_cmsisdap_info(&device, false))
            .collect(),
        Err(e) => {
            tracing::warn!("error listing devices with nusb: {e}");
            vec![]
        }
    };

    #[cfg(feature = "cmsisdap_v1")]
    tracing::debug!(
        "Found {} CMSIS-DAP probes using nusb, searching HID",
        probes.len()
    );

    #[cfg(feature = "cmsisdap_v1")]
    if let Ok(api) = hidapi::HidApi::new() {
        for device in api.device_list() {
            if let Some(info) = get_cmsisdap_hid_info(device) {
                if !probes.iter().any(|p| {
                    p.vendor_id == info.vendor_id
                        && p.product_id == info.product_id
                        && p.serial_number == info.serial_number
                }) {
                    tracing::trace!("Adding new HID-only probe {:?}", info);
                    probes.push(info)
                } else {
                    tracing::trace!("Ignoring duplicate {:?}", info);
                }
            }
        }
    }

    tracing::debug!("Found {} CMSIS-DAP probes total", probes.len());
    probes
}

/// Checks if a given Device is a CMSIS-DAP probe, returning Some(DebugProbeInfo) if so.
///
/// If `list_both_versions` is true, both v1 and v2 interfaces will be returned.
/// Otherwise, only v2 interfaces will be returned, unless there are no v2 interfaces,
/// in which case v1 interfaces will be returned.
///
/// To list probes, this function should be called with `list_both_versions` set to false,
/// so that devices with both v1 and v2 interfaces are listed only once.
///
/// To open a probe, this function should be called with `list_both_versions` set to true,
/// so that the user can manually fall back to the v1 interface.
fn get_cmsisdap_info(device: &DeviceInfo, list_both_versions: bool) -> Vec<DebugProbeInfo> {
    // Open device handle and read basic information
    let prod_str = device.product_string().unwrap_or("");
    let sn_str = device.serial_number();

    // Most CMSIS-DAP probes say something like "CMSIS-DAP"
    let cmsis_dap_product = is_cmsis_dap(prod_str) || is_known_cmsis_dap_dev(device);

    let mut v1_ifaces = vec![];
    let mut v2_ifaces = vec![];

    // Iterate all interfaces, looking for:
    // 1. Any with CMSIS-DAP in their interface string
    // 2. Any that are HID, if the product string says CMSIS-DAP,
    //    to save for potential HID-only operation.
    for interface in device.interfaces() {
        let Some(interface_desc) = interface.interface_string() else {
            tracing::trace!(
                "interface {} has no string, skipping",
                interface.interface_number()
            );
            continue;
        };
        if is_cmsis_dap(interface_desc) {
            tracing::trace!(
                "  Interface {}: {}",
                interface.interface_number(),
                interface_desc,
            );
            let selected_interface = Some(interface.interface_number());
            let is_hid_interface = if interface.class() == USB_CLASS_HID {
                tracing::trace!("    HID interface found");
                true
            } else if (interface.class(), interface.subclass())
                != (USB_CMSIS_DAP_CLASS, USB_CMSIS_DAP_SUBCLASS)
            {
                tracing::trace!(
                    "Interface {} has a cmsis-dap description but wrong classes ({}, {}), skipping",
                    interface.interface_number(),
                    interface.class(),
                    interface.subclass(),
                );
                // Not a CMSIS-DAP v2 interface, skip.
                continue;
            } else {
                false
            };

            let info = DebugProbeInfo::new(
                prod_str.to_string(),
                device.vendor_id(),
                device.product_id(),
                sn_str.map(Into::into),
                &CmsisDapFactory,
                selected_interface,
                is_hid_interface,
            );

            if is_hid_interface {
                v1_ifaces.push(info);
            } else {
                v2_ifaces.push(info);
            }
        }
    }

    if cmsis_dap_product {
        tracing::trace!(
            "{}: CMSIS-DAP device with {} interfaces",
            prod_str,
            device.interfaces().count()
        );
        if !v1_ifaces.is_empty() {
            tracing::trace!("Device has {} CMSIS-DAPv1 interfaces", v1_ifaces.len());
        }
        if !v2_ifaces.is_empty() {
            tracing::trace!("Device has {} CMSIS-DAPv2 interfaces", v2_ifaces.len());
        }
    }
    // Make sure cmsis-dap v2 interfaces are tried first
    let mut results = v2_ifaces;
    if list_both_versions || results.is_empty() {
        results.extend(v1_ifaces);
    }
    results
}

/// Checks if a given HID device is a CMSIS-DAP v1 probe, returning Some(DebugProbeInfo) if so.
#[cfg(feature = "cmsisdap_v1")]
fn get_cmsisdap_hid_info(device: &hidapi::DeviceInfo) -> Option<DebugProbeInfo> {
    let prod_str = device.product_string().unwrap_or("");
    let path = device.path().to_str().unwrap_or("");
    if is_cmsis_dap(prod_str) || is_cmsis_dap(path) {
        tracing::trace!("CMSIS-DAP device with USB path: {:?}", device.path());
        tracing::trace!("                product_string: {:?}", prod_str);
        tracing::trace!(
            "                     interface: {}",
            device.interface_number()
        );

        Some(DebugProbeInfo::new(
            prod_str.to_owned(),
            device.vendor_id(),
            device.product_id(),
            device.serial_number().map(|s| s.to_owned()),
            &CmsisDapFactory,
            Some(device.interface_number() as u8),
            true,
        ))
    } else {
        None
    }
}

/// Attempt to open the given device in CMSIS-DAP v2 mode
pub fn open_v2_device(
    device_info: &DeviceInfo,
    selected_interface: Option<u8>,
) -> Result<Option<CmsisDapDevice>, ProbeCreationError> {
    // Open device handle and read basic information
    let vid = device_info.vendor_id();
    let pid = device_info.product_id();

    tracing::trace!(
        "Trying to open {:04x}:{:04x} in cmsis-dap v2 mode",
        vid,
        pid
    );

    let device = match device_info.open().wait() {
        Ok(device) => device,
        Err(e) => {
            tracing::debug!(
                vendor_id = %format!("{vid:04x}"),
                product_id = %format!("{pid:04x}"),
                error = %e,
                "failed to open device for CMSIS-DAP v2"
            );
            return Ok(None);
        }
    };

    // Go through interfaces to try and find a v2 interface.
    // The CMSIS-DAPv2 spec says that v2 interfaces should use a specific
    // WinUSB interface GUID, but in addition to being hard to read, the
    // official DAPLink firmware doesn't use it. Instead, we scan for an
    // interface whose string like "CMSIS-DAP" and has two or three
    // endpoints of the correct type and direction.
    let Some(c_desc) = device.configurations().next() else {
        tracing::trace!("No cmsis-dap v2 interface found");
        return Ok(None);
    };
    for interface in c_desc.interfaces() {
        tracing::trace!("Checking interface {}", interface.interface_number());
        if let Some(iface) = selected_interface
            && interface.interface_number() != iface
        {
            tracing::trace!(
                "Interface number does not match selector {} != {}",
                iface,
                interface.interface_number()
            );
            continue;
        }
        for i_desc in interface.alt_settings() {
            // Skip interfaces without "CMSIS-DAP" like pattern in their string
            let Some(interface_str) = device_info
                .interfaces()
                .find(|i| i.interface_number() == interface.interface_number())
                .and_then(|i| i.interface_string())
            else {
                tracing::trace!("Interface does not have interface string");
                continue;
            };
            if !is_cmsis_dap(interface_str) {
                tracing::trace!("Interface does not have 'CMSIS-DAP' in string");
                continue;
            }

            // Skip interfaces without 2 or 3 endpoints
            let n_ep = i_desc.num_endpoints();
            if !(2..=3).contains(&n_ep) {
                tracing::trace!(
                    "Interface does not have the correct number of endpoints ({})",
                    n_ep
                );
                continue;
            }

            let eps: Vec<_> = i_desc.endpoints().collect();

            // Check the first endpoint is bulk out
            if eps[0].transfer_type() != TransferType::Bulk || eps[0].direction() != Direction::Out
            {
                tracing::trace!("First interface endpoint is not bulk out");
                continue;
            }

            // Check the second endpoint is bulk in
            if eps[1].transfer_type() != TransferType::Bulk || eps[1].direction() != Direction::In {
                tracing::trace!("Second interface endpoint is not bulk in");
                continue;
            }

            // Detect a third bulk EP which will be for SWO streaming
            let mut swo_ep = None;

            if eps.len() > 2
                && eps[2].transfer_type() == TransferType::Bulk
                && eps[2].direction() == Direction::In
            {
                swo_ep = Some((eps[2].address(), eps[2].max_packet_size()));
            }
            // Attempt to claim this interface
            match device.claim_interface(interface.interface_number()).wait() {
                Ok(handle) => {
                    tracing::debug!("Opening {:04x}:{:04x} in CMSIS-DAPv2 mode", vid, pid);
                    reject_probe_by_version(
                        device_info.vendor_id(),
                        device_info.product_id(),
                        device_info.device_version(),
                    )?;
                    return Ok(Some(CmsisDapDevice::V2 {
                        handle,
                        out_ep: eps[0].address(),
                        in_ep: eps[1].address(),
                        swo_ep,
                        max_packet_size: eps[1].max_packet_size(),
                        usb_timeout: DEFAULT_USB_TIMEOUT,
                    }));
                }
                Err(e) => {
                    tracing::debug!(
                        interface = interface.interface_number(),
                        error = %e,
                        "failed to claim interface"
                    );
                    continue;
                }
            }
        }
    }

    // Could not open in v2
    tracing::debug!(
        "Could not open {:04x}:{:04x} in CMSIS-DAP v2 mode",
        vid,
        pid
    );
    Ok(None)
}

fn reject_probe_by_version(
    vendor_id: u16,
    product_id: u16,
    device_version: u16,
) -> Result<(), ProbeCreationError> {
    let denylist = [
        |vid, pid, version| (vid == 0x2e8a && pid == 0x000c && version < 0x0220).then_some("2.2.0"), // Old RPi debugprobe
    ];

    tracing::debug!(
        "Checking against denylist: {:04x}:{:04x} v{:04x}",
        vendor_id,
        product_id,
        device_version
    );
    for deny in denylist {
        if let Some(min_version) = deny(vendor_id, product_id, device_version) {
            return Err(ProbeCreationError::ProbeSpecific(BoxedProbeError::from(
                CmsisDapError::ProbeFirmwareOutdated(min_version),
            )));
        }
    }

    Ok(())
}

/// Attempt to open the given DebugProbeInfo in CMSIS-DAP v2 mode if possible,
/// otherwise in v1 mode.
pub fn open_device_from_selector(
    selector: &DebugProbeSelector,
) -> Result<CmsisDapDevice, ProbeCreationError> {
    tracing::trace!("Attempting to open device matching {}", selector);

    // We need to use nusb to detect the proper HID interface to use
    // if a probe has multiple HID interfaces. The hidapi lib unfortunately
    // offers no method to get the interface description string directly,
    // so we retrieve the device information using nusb and store it here.
    //
    // If nusb cannot be used, we will just use the first HID interface and
    // try to open that.
    #[cfg(feature = "cmsisdap_v1")]
    let mut hid_device_info = None;

    // Try using nusb to open a v2 device. This might fail if
    // the device does not support v2 operation or due to driver
    // or permission issues with opening bulk devices.
    match nusb::list_devices().wait() {
        Ok(devices) => {
            for device in devices {
                tracing::trace!("Trying device {:?}", device);

                if selector.matches(&device)
                    && let Some(device_info) =
                        get_cmsisdap_info(&device, true).into_iter().find(|dpi| {
                            tracing::trace!("DebugProbeInfo: {:?}", dpi);
                            // Only compare if the selector has an interface to compare to
                            selector.interface.is_none_or(|i| Some(i) == dpi.interface)
                        })
                {
                    // If the VID, PID, and potentially SN all match,
                    // and the device is a valid CMSIS-DAP probe,
                    // attempt to open the device in v2 mode.
                    if let Some(device) = open_v2_device(&device, device_info.interface)? {
                        return Ok(device);
                    } else {
                        #[cfg(feature = "cmsisdap_v1")]
                        {
                            // Otherwise, save as a potential CMSIS-DAP v1 HID device and continue.
                            hid_device_info = Some(device_info);
                        }
                    }
                }

                tracing::trace!("Device did not match");
            }
        }
        Err(e) => {
            tracing::debug!("No devices matched using nusb: {e}");
        }
    }

    #[cfg(not(feature = "cmsisdap_v1"))]
    return Err(ProbeCreationError::NotFound);

    #[cfg(feature = "cmsisdap_v1")]
    {
        // If nusb failed or the device didn't support v2, try using hidapi to open in v1 mode.
        let vid = selector.vendor_id;
        let pid = selector.product_id;
        let sn = selector.serial_number.as_deref();

        tracing::debug!(
            "Attempting to open {:04x}:{:04x} in CMSIS-DAP v1 mode",
            vid,
            pid
        );

        // Attempt to open provided VID/PID/SN with hidapi

        let Ok(hid_api) = HidApi::new() else {
            return Err(ProbeCreationError::NotFound);
        };

        let mut device_list = hid_api.device_list();

        // We have to filter manually so that we can check the correct HID interface number.
        // Using HidApi::open() will return the first device which matches PID and VID,
        // which is not always what we want.
        let device_info = device_list
            .find(|info| {
                let mut device_match = info.vendor_id() == vid && info.product_id() == pid;

                if let Some(sn) = sn {
                    device_match &= Some(sn) == info.serial_number();
                }

                if let Some(hid_interface) = hid_device_info
                    .as_ref()
                    .and_then(|info| info.interface.filter(|_| info.is_hid_interface))
                {
                    device_match &= info.interface_number() == hid_interface as i32;
                }

                device_match
            })
            .ok_or(ProbeCreationError::NotFound)?;

        let Ok(device) = device_info.open_device(&hid_api) else {
            return Err(ProbeCreationError::NotFound);
        };

        match device.get_product_string() {
            Ok(Some(s)) if is_cmsis_dap(&s) => {
                reject_probe_by_version(
                    device_info.vendor_id(),
                    device_info.product_id(),
                    device_info.release_number(),
                )?;
                Ok(CmsisDapDevice::V1 {
                    handle: device,
                    report_size: hid_report_size(device_info),
                    usb_timeout: DEFAULT_USB_TIMEOUT,
                })
            }
            _ => {
                // Return NotFound if this VID:PID was not a valid CMSIS-DAP probe,
                // or if it couldn't be opened, so that other probe modules can
                // attempt to open it instead.
                Err(ProbeCreationError::NotFound)
            }
        }
    }
}

/// We recognise cmsis dap interfaces if they have string like "CMSIS-DAP"
/// in them. As devices spell CMSIS DAP differently we go through known
/// spellings/patterns looking for a match
fn is_cmsis_dap(id: &str) -> bool {
    id.contains("CMSIS-DAP") || id.contains("CMSIS_DAP")
}

/// Some devices don't have a CMSIS-DAP interface string, but are still
/// CMSIS-DAP probes. We hardcode a list of known VID/PID pairs here.
fn is_known_cmsis_dap_dev(device: &DeviceInfo) -> bool {
    // - 1a86:8012 WCH-Link in DAP mode, This shares the same description string as the
    //   WCH-Link in RV mode, so we have to check by vendor ID and product ID.
    const KNOWN_DAPS: &[(u16, u16)] = &[(0x1a86, 0x8012)];

    KNOWN_DAPS
        .iter()
        .any(|&(vid, pid)| device.vendor_id() == vid && device.product_id() == pid)
}

/// Manual override of HID report size
///
/// This is only needed for devices which:
///
/// 1. Don't use the default 64 bytes, and
/// 2. Don't respond to being asked the report size until they've received a full packet,
///    causing a long delay at startup as many 64-byte packets must be sent with a timeout
///    between each one.
///
/// Devices not on this list will still work but with a slow startup time
/// as the packet size is auto-determined.
#[cfg(feature = "cmsisdap_v1")]
fn hid_report_size(device: &hidapi::DeviceInfo) -> usize {
    // EDBG are 512-bytes and don't respond until you give them 512 bytes.
    if device.vendor_id() == 0x03eb
        && let Some(s) = device.product_string()
        && s.contains("EDBG")
    {
        tracing::debug!("Overriding packet size to 512 bytes for EDBG device");
        return 512;
    }

    // Default for almost all CMSIS-DAPv1 devices.
    // Devices are queried at startup for their packet size so it can usually be increased quickly
    // if needed; only some devices are annoying to query the packet size so are worth an override.
    64
}