dist/tools/bmp: improve auto-detection of firmware

Parse the version number from the product description as returned by
libusb. This works for stable firmware releases, and ensures that
older firmwares work out of the box.

dist/tools/bmp/README.md

@@ -51,13 +51,17 @@ The probe is auto discovered based on the USB VID (0x1D50) and PID (0x6018,
 `--serial` is provided.
 
 If `--port` is provided, then that port will be used as the GDB port for all
-actions, except for the `term` action.
+actions, except for the `term` action. `--port` also accepts values such as
+network addresses.
 
 ## Supported firmwares
-This tool assumes firmware version 1.10 of the Black Magic debugger.
+There are minor differences in the available firmwares of the Black Magic
+debugger. Compatibility has been tested with version 1.8+.
 
-Compatibility for older versions is limited, but can be selected by providing
-`--bmp-version x.y.z`.
+This tool will try to determine which version of the firmware is installed,
+unless the probe is accessed remotely (e.g. `--port` is a network address). If
+the firmware version cannot be determined, it will assume version 1.10.2. This
+can be overridden using the `--bmp-version` flag.
 
 ## Examples (tested with BluePill STM32F103F8C6)
 * test connection:

dist/tools/bmp/bmp.py

@@ -25,6 +25,7 @@
 from pygdbmi.gdbcontroller import GdbController
 
 TIMEOUT = 100  # seconds
+DEFAULT_VERSION = Version('1.10.2')
 
 
 # find a suitable gdb executable, falling back to defaults if needed
@@ -41,12 +42,24 @@ def find_suitable_gdb(gdb_path):
     sys.exit(-1)
 
 
+# detect the firmware version by parsing the product description for something like v1.10.2
+def detect_firmware_version(port):
+    matches = re.search(r"v[0-9]+.[0-9]+.[0-9]+", port.product)
+
+    if not matches:
+        return None
+
+    return Version(matches.group(0)[1:])
+
+
 # find all connected BMPs and store both GDB and UART interfaces
 def detect_probes():
     gdb_ports = []
     uart_ports = []
     for p in serial.tools.list_ports.comports():
         if p.vid == 0x1D50 and p.pid in {0x6018, 0x6017}:
+            p.firmware_version = detect_firmware_version(p)
+
             if re.fullmatch(r'COM\d\d', p.device):
                 p.device = '//./' + p.device
             if 'GDB' in str(p.interface) \
@@ -65,6 +78,8 @@ def enumerate_probes(ports):
         print(f"\t[{s.device}]", end=' ')
         if len(s.serial_number) > 1:
             print(f"Serial: {s.serial_number}", end=' ')
+        if s.firmware_version:
+            print(f"Firmware: {s.firmware_version}", end=' ')
         if i == 0:
             print("<- default", end=' ')
         print('')
@@ -74,7 +89,14 @@ def enumerate_probes(ports):
 def search_serial(snr, ports):
     for port in ports:
         if snr in port.serial_number:
-            return port.device
+            return port
+
+
+# search device with specific port number <prt> in a list of ports <ports>
+def search_port(prt, ports):
+    for port in ports:
+        if prt == port.device:
+            return port
 
 
 # parse GDB output for targets
@@ -167,20 +189,41 @@ def check_flash(gdbmi):
         res = gdbmi.get_gdb_response(timeout_sec=TIMEOUT)
 
 
-# choose GDB or UART port, based on available ports and application arguments
-def choose_port(args, ports):
-    if args.port:
-        port = args.port
+# choose GDB or UART port, based on available ports and application arguments.
+def choose_probe(args, ports):
+    if args.serial:
+        descriptor = search_serial(args.serial, ports)
+        assert descriptor, "no BMP with this serial found"
+    elif args.port:
+        descriptor = search_port(args.port, ports)
+
+        # bail out if no descriptor found, because port could be a network address, a pipe or
+        # something else.
+        if not descriptor:
+            return (args.port, None)
     else:
-        enumerate_probes(ports)
-        if args.serial:
-            port = search_serial(args.serial, ports)
-            assert port, "no BMP with this serial found"
+        assert len(ports) > 0, "no ports found"
+        descriptor = ports[0]
+
+    enumerate_probes(ports)
+    print(f'connecting to [{descriptor.device}]...')
+    return (descriptor.device, descriptor)
+
+
+# choose firmware version, based on available descriptors and application arguments.
+def choose_firmware_version(args, descriptor):
+    if args.bmp_version == "auto":
+        if descriptor and descriptor.firmware_version:
+            version = descriptor.firmware_version
+            print(f"auto-detected firmware version {version}")
         else:
-            assert len(ports) > 0, "no ports found"
-            port = ports[0].device
-    print(f'connecting to [{port}]...')
-    return port
+            version = DEFAULT_VERSION
+            print(f"unable to detect firmware version, assuming {version} or later")
+    else:
+        version = Version(args.bmp_version)
+        print(f"using firmware version {version}")
+
+    return version
 
 
 # terminal mode, opens TTY program
@@ -258,7 +301,7 @@ def parse_args():
     parser.add_argument('--port', help='choose specific probe by port (overrides auto selection)')
     parser.add_argument('--attach', help='choose specific target by number', type=int, default='1')
     parser.add_argument('--gdb-path', help='path to GDB', default='gdb-multiarch')
-    parser.add_argument('--bmp-version', help='choose specific firmware version', default='1.10.0')
+    parser.add_argument('--bmp-version', help='choose specific firmware version', default='auto')
     parser.add_argument('--term-cmd', help='serial terminal command',
                         default='picocom --nolock --imap lfcrlf --baud 115200 %s')
 
@@ -277,14 +320,14 @@ def main():
     g, u = detect_probes()
 
     if args.action == 'term':
-        port = choose_port(args, u)
+        (port, _) = choose_probe(args, u)
 
         term_mode(args, port)
     else:
-        port = choose_port(args, g)
+        (port, descriptor) = choose_probe(args, g)
 
         args.file = args.file if args.file else ''
-        args.bmp_version = Version(args.bmp_version)
+        args.bmp_version = choose_firmware_version(args, descriptor)
         args.gdb_path = find_suitable_gdb(args.gdb_path)
 
         if args.action == 'debug':