wip (+4 squashed commits)

Squashed commits:
[d29a350] wip
[7f541ed] wip
[1e2902e] basic working version
[14b497a] wip

bumble/drivers/__init__.py

@@ -0,0 +1,68 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+Drivers that can be used to customize the interaction between a host and a controller,
+like loading firmware after a cold start.
+"""
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import abc
+import logging
+from . import rtk
+
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Classes
+# -----------------------------------------------------------------------------
+class Driver(abc.ABC):
+    """Base class for drivers."""
+
+    @staticmethod
+    async def for_host(_host):
+        """Return a driver instance for a host.
+
+        Args:
+            host: Host object for which a driver should be created.
+
+        Returns:
+            A Driver instance if a driver should be instantiated for this host, or
+            None if no driver instance of this class is needed.
+        """
+        return None
+
+    @abc.abstractmethod
+    async def init_controller(self):
+        """Initialize the controller."""
+
+
+# -----------------------------------------------------------------------------
+# Functions
+# -----------------------------------------------------------------------------
+async def get_driver_for_host(host):
+    """Probe all known diver classes until one returns a valid instance for a host,
+    or none is found.
+    """
+    if (driver := await rtk.Driver.for_host(host)):
+        logger.debug("Instantiated RTK driver")
+        return driver
+
+    return None

bumble/drivers/rtk.py

@@ -0,0 +1,604 @@
+# Copyright 2021-2023 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+Support for Realtek USB dongles.
+Based on various online bits of information, including the Linux kernel.
+(see `drivers/bluetooth/btrtl.c`)
+"""
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+from dataclasses import dataclass
+import asyncio
+import enum
+import logging
+import math
+import os
+import pathlib
+import struct
+import weakref
+
+
+from bumble.hci import (
+    hci_command_op_code,
+    STATUS_SPEC,
+    HCI_SUCCESS,
+    HCI_COMMAND_NAMES,
+    HCI_Command,
+    HCI_Reset_Command,
+    HCI_Read_Local_Version_Information_Command,
+)
+
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+# Constants
+# -----------------------------------------------------------------------------
+RTK_ROM_LMP_8723A = 0x1200
+RTK_ROM_LMP_8723B = 0x8723
+RTK_ROM_LMP_8821A = 0x8821
+RTK_ROM_LMP_8761A = 0x8761
+RTK_ROM_LMP_8822B = 0x8822
+RTK_ROM_LMP_8852A = 0x8852
+RTK_CONFIG_MAGIC = 0x8723AB55
+
+RTK_EPATCH_SIGNATURE = b"Realtech"
+
+RTK_FRAGMENT_LENGTH = 252
+
+RTK_FIRMWARE_DIR_ENV = "BUMBLE_RTK_FIRMWARE_DIR"
+
+
+class RtlProjectId(enum.IntEnum):
+    PROJECT_ID_8723A = 0
+    PROJECT_ID_8723B = 1
+    PROJECT_ID_8821A = 2
+    PROJECT_ID_8761A = 3
+    PROJECT_ID_8822B = 8
+    PROJECT_ID_8723D = 9
+    PROJECT_ID_8821C = 10
+    PROJECT_ID_8822C = 13
+    PROJECT_ID_8761B = 14
+    PROJECT_ID_8852A = 18
+    PROJECT_ID_8852B = 20
+    PROJECT_ID_8852C = 25
+
+
+RTK_PROJECT_ID_TO_ROM = {
+    0: RTK_ROM_LMP_8723A,
+    1: RTK_ROM_LMP_8723B,
+    2: RTK_ROM_LMP_8821A,
+    3: RTK_ROM_LMP_8761A,
+    8: RTK_ROM_LMP_8822B,
+    9: RTK_ROM_LMP_8723B,
+    10: RTK_ROM_LMP_8821A,
+    13: RTK_ROM_LMP_8822B,
+    14: RTK_ROM_LMP_8761A,
+    18: RTK_ROM_LMP_8852A,
+    20: RTK_ROM_LMP_8852A,
+    25: RTK_ROM_LMP_8852A,
+}
+
+# List of USB (VendorID, ProductID) for Realtek-based devices.
+RTK_USB_PRODUCTS = {
+    # Realtek 8723AE
+    (0x0930, 0x021D),
+    (0x13D3, 0x3394),
+    # Realtek 8723BE
+    (0x0489, 0xE085),
+    (0x0489, 0xE08B),
+    (0x04F2, 0xB49F),
+    (0x13D3, 0x3410),
+    (0x13D3, 0x3416),
+    (0x13D3, 0x3459),
+    (0x13D3, 0x3494),
+    # Realtek 8723BU
+    (0x7392, 0xA611),
+    # Realtek 8723DE
+    (0x0BDA, 0xB009),
+    (0x2FF8, 0xB011),
+    # Realtek 8761BUV
+    (0x2357, 0x0604),
+    (0x0B05, 0x190E),
+    (0x2550, 0x8761),
+    (0x0BDA, 0x8771),
+    (0x7392, 0xC611),
+    (0x2B89, 0x8761),
+    (0x2230, 0x0016),
+    # Realtek 8821AE
+    (0x0B05, 0x17DC),
+    (0x13D3, 0x3414),
+    (0x13D3, 0x3458),
+    (0x13D3, 0x3461),
+    (0x13D3, 0x3462),
+    # Realtek 8822BE
+    (0x13D3, 0x3526),
+    (0x0B05, 0x185C),
+    # Realtek 8822CE
+    (0x04CA, 0x4005),
+    (0x04C5, 0x161F),
+    (0x0B05, 0x18EF),
+    (0x13D3, 0x3548),
+    (0x13D3, 0x3549),
+    (0x13D3, 0x3553),
+    (0x13D3, 0x3555),
+    (0x2FF8, 0x3051),
+    (0x1358, 0xC123),
+    (0x0BDA, 0xC123),
+    (0x0CB5, 0xC547),
+}
+
+# -----------------------------------------------------------------------------
+# HCI Commands
+# -----------------------------------------------------------------------------
+HCI_RTK_READ_ROM_VERSION_COMMAND = hci_command_op_code(0x3F, 0x6D)
+HCI_COMMAND_NAMES[HCI_RTK_READ_ROM_VERSION_COMMAND] = "HCI_RTK_READ_ROM_VERSION_COMMAND"
+
+
+@HCI_Command.command(return_parameters_fields=[("status", STATUS_SPEC), ("version", 1)])
+class HCI_RTK_Read_ROM_Version_Command(HCI_Command):
+    pass
+
+
+HCI_RTK_DOWNLOAD_COMMAND = hci_command_op_code(0x3F, 0x20)
+HCI_COMMAND_NAMES[HCI_RTK_DOWNLOAD_COMMAND] = "HCI_RTK_DOWNLOAD_COMMAND"
+
+
+@HCI_Command.command(
+    fields=[("index", 1), ("payload", RTK_FRAGMENT_LENGTH)],
+    return_parameters_fields=[("status", STATUS_SPEC), ("index", 1)],
+)
+class HCI_RTK_Download_Command(HCI_Command):
+    pass
+
+
+HCI_RTK_DROP_FIRMWARE_COMMAND = hci_command_op_code(0x3F, 0x66)
+HCI_COMMAND_NAMES[HCI_RTK_DROP_FIRMWARE_COMMAND] = "HCI_RTK_DROP_FIRMWARE_COMMAND"
+
+
+@HCI_Command.command()
+class HCI_RTK_Drop_Firmware_Command(HCI_Command):
+    pass
+
+
+# -----------------------------------------------------------------------------
+class Firmware:
+    def __init__(self, firmware):
+        extension_sig = bytes([0x51, 0x04, 0xFD, 0x77])
+
+        if not firmware.startswith(RTK_EPATCH_SIGNATURE):
+            raise ValueError("Firmware does not start with epatch signature")
+
+        if not firmware.endswith(extension_sig):
+            raise ValueError("Firmware does not end with extension sig")
+
+        # The firmware should start with a 14 byte header.
+        epatch_header_size = 14
+        if len(firmware) < epatch_header_size:
+            raise ValueError("Firmware too short")
+
+        # Look for the "project ID", starting from the end.
+        offset = len(firmware) - len(extension_sig)
+        project_id = -1
+        while offset >= epatch_header_size:
+            length, opcode = firmware[offset - 2 : offset]
+            offset -= 2
+
+            if opcode == 0xFF:
+                # End
+                break
+
+            if length == 0:
+                raise ValueError("Invalid 0-length instruction")
+
+            if opcode == 0 and length == 1:
+                project_id = firmware[offset - 1]
+                break
+
+            offset -= length
+
+        if project_id < 0:
+            raise ValueError("Project ID not found")
+
+        self.project_id = project_id
+
+        # Read the patch tables info.
+        self.version, num_patches = struct.unpack("<IH", firmware[8:14])
+        self.patches = []
+
+        # The patches tables are laid out as:
+        # <ChipID_1><ChipID_2>...<ChipID_N>  (16 bits each)
+        # <PatchLength_1><PatchLength_2>...<PatchLength_N> (16 bits each)
+        # <PatchOffset_1><PatchOffset_2>...<PatchOffset_N> (32 bits each)
+        if epatch_header_size + 8 * num_patches > len(firmware):
+            raise ValueError("Firmware too short")
+        chip_id_table_offset = epatch_header_size
+        patch_length_table_offset = chip_id_table_offset + 2 * num_patches
+        patch_offset_table_offset = chip_id_table_offset + 4 * num_patches
+        for patch_index in range(num_patches):
+            chip_id_offset = chip_id_table_offset + 2 * patch_index
+            (chip_id,) = struct.unpack_from("<H", firmware, chip_id_offset)
+            (patch_length,) = struct.unpack_from(
+                "<H", firmware, patch_length_table_offset + 2 * patch_index
+            )
+            (patch_offset,) = struct.unpack_from(
+                "<I", firmware, patch_offset_table_offset + 4 * patch_index
+            )
+            if patch_offset + patch_length > len(firmware):
+                raise ValueError("Firmware too short")
+
+            # Get the SVN version for the patch
+            (svn_version,) = struct.unpack_from(
+                "<I", firmware, patch_offset + patch_length - 8
+            )
+
+            # Create a payload with the patch, replacing the last 4 bytes with
+            # the firmware version.
+            self.patches.append(
+                (
+                    chip_id,
+                    firmware[patch_offset : patch_offset + patch_length - 4]
+                    + struct.pack("<I", self.version),
+                    svn_version
+                )
+            )
+
+
+class Driver:
+    @dataclass
+    class DriverInfo:
+        rom: int
+        hci: tuple[int, int]
+        config_needed: bool
+        has_rom_version: bool
+        has_msft_ext: bool = False
+        fw_name: str = ""
+        config_name: str = ""
+
+    DRIVER_INFOS = [
+        # 8723A
+        DriverInfo(
+            rom=RTK_ROM_LMP_8723A,
+            hci=(0x0B, 0x06),
+            config_needed=False,
+            has_rom_version=False,
+            fw_name="rtl8723a_fw.bin",
+            config_name="",
+        ),
+        # 8723B
+        DriverInfo(
+            rom=RTK_ROM_LMP_8723B,
+            hci=(0x0B, 0x06),
+            config_needed=False,
+            has_rom_version=True,
+            fw_name="rtl8723b_fw.bin",
+            config_name="rtl8723b_config.bin",
+        ),
+        # 8723D
+        DriverInfo(
+            rom=RTK_ROM_LMP_8723B,
+            hci=(0x0D, 0x08),
+            config_needed=True,
+            has_rom_version=True,
+            fw_name="rtl8723d_fw.bin",
+            config_name="rtl8723d_config.bin",
+        ),
+        # 8821A
+        DriverInfo(
+            rom=RTK_ROM_LMP_8821A,
+            hci=(0x0A, 0x06),
+            config_needed=False,
+            has_rom_version=True,
+            fw_name="rtl8821a_fw.bin",
+            config_name="rtl8821a_config.bin",
+        ),
+        # 8821C
+        DriverInfo(
+            rom=RTK_ROM_LMP_8821A,
+            hci=(0x0C, 0x08),
+            config_needed=False,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8821c_fw.bin",
+            config_name="rtl8821c_config.bin",
+        ),
+        # 8761A
+        DriverInfo(
+            rom=RTK_ROM_LMP_8761A,
+            hci=(0x0A, 0x06),
+            config_needed=False,
+            has_rom_version=True,
+            fw_name="rtl8761a_fw.bin",
+            config_name="rtl8761a_config.bin",
+        ),
+        # 8761BU
+        DriverInfo(
+            rom=RTK_ROM_LMP_8761A,
+            hci=(0x0B, 0x0A),
+            config_needed=False,
+            has_rom_version=True,
+            fw_name="rtl8761bu_fw.bin",
+            config_name="rtl8761bu_config.bin",
+        ),
+        # 8822C
+        DriverInfo(
+            rom=RTK_ROM_LMP_8822B,
+            hci=(0x0C, 0x0A),
+            config_needed=False,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8822cu_fw.bin",
+            config_name="rtl8822cu_config.bin",
+        ),
+        # 8822B
+        DriverInfo(
+            rom=RTK_ROM_LMP_8822B,
+            hci=(0x0B, 0x07),
+            config_needed=True,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8822b_fw.bin",
+            config_name="rtl8822b_config.bin",
+        ),
+        # 8852A
+        DriverInfo(
+            rom=RTK_ROM_LMP_8852A,
+            hci=(0x0A, 0x0B),
+            config_needed=False,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8852au_fw.bin",
+            config_name="rtl8852au_config.bin",
+        ),
+        # 8852B
+        DriverInfo(
+            rom=RTK_ROM_LMP_8852A,
+            hci=(0xB, 0xB),
+            config_needed=False,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8852bu_fw.bin",
+            config_name="rtl8852bu_config.bin",
+        ),
+        # 8852C
+        DriverInfo(
+            rom=RTK_ROM_LMP_8852A,
+            hci=(0x0C, 0x0C),
+            config_needed=False,
+            has_rom_version=True,
+            has_msft_ext=True,
+            fw_name="rtl8852cu_fw.bin",
+            config_name="rtl8852cu_config.bin",
+        ),
+    ]
+
+    POST_DROP_DELAY = 0.2
+
+    @staticmethod
+    def find_driver_info(hci_version, hci_subversion, lmp_subversion):
+        for driver_info in Driver.DRIVER_INFOS:
+            if driver_info.rom == lmp_subversion and driver_info.hci == (
+                hci_subversion,
+                hci_version,
+            ):
+                return driver_info
+
+        return None
+
+    @staticmethod
+    def find_binary_path(file_name):
+        # First check if an environment variable is set
+        if RTK_FIRMWARE_DIR_ENV in os.environ:
+            if (path := pathlib.Path(os.environ[RTK_FIRMWARE_DIR_ENV])).is_file():
+                logger.debug(f"{file_name} found in env dir")
+                return path
+
+            # When the environment variable is set, don't look elsewhere
+            return None
+
+        # Then, look in the package's driver directory
+        directory = pathlib.Path(__file__).parent / "rtl"
+        if directory.is_dir() and (path := (directory / file_name)).is_file():
+            logger.debug(f"{file_name} found in package dir")
+            return path
+
+        # Finally look in the current directory
+        if (path := (pathlib.Path.cwd() / file_name)).is_file():
+            logger.debug(f"{file_name} found in CWD")
+            return path
+
+        return None
+
+    @staticmethod
+    def check(host):
+        if not host.hci_metadata:
+            logger.debug("USB metadata not found")
+            return False
+
+        vendor_id = host.hci_metadata.get("vendor_id", None)
+        product_id = host.hci_metadata.get("product_id", None)
+        if vendor_id is None or product_id is None:
+            logger.debug("USB metadata not sufficient")
+            return False
+
+        if (vendor_id, product_id) not in RTK_USB_PRODUCTS:
+            logger.debug("USB device not in known list")
+            return False
+
+        return True
+
+    @classmethod
+    async def driver_info_for_host(cls, host):
+        response = await host.send_command(
+            HCI_Read_Local_Version_Information_Command(), check_result=True
+        )
+        local_version = response.return_parameters
+
+        logger.debug(
+            f"looking for a driver: 0x{local_version.lmp_subversion:04X} "
+            f"(0x{local_version.hci_version:02X}, "
+            f"0x{local_version.hci_subversion:04X})"
+        )
+
+        driver_info = cls.find_driver_info(
+            local_version.hci_version,
+            local_version.hci_subversion,
+            local_version.lmp_subversion,
+        )
+        if driver_info is None:
+            # TODO: it seems that the Linux driver will send command (0x3f, 0x66)
+            # in this case and then re-read the local version, then re-match.
+            logger.debug("firmware already loaded or no known driver for this device")
+
+        return driver_info
+
+    @classmethod
+    async def for_host(cls, host, force=False):
+        # Check that a driver is needed for this host
+        if not force and not cls.check(host):
+            return None
+
+        # Get the driver info
+        if (driver_info := await cls.driver_info_for_host(host)) is None:
+            return None
+
+        # Load the firmware
+        firmware_path = cls.find_binary_path(driver_info.fw_name)
+        if not firmware_path:
+            logger.warning("Firmware file not found")
+            return None
+        with open(firmware_path, "rb") as firmware_file:
+            firmware = firmware_file.read()
+
+        # Load the config
+        config = None
+        if driver_info.config_name:
+            config_path = cls.find_binary_path(driver_info.config_name)
+            if config_path:
+                with open(driver_info.config_name, "rb") as config_file:
+                    config = config_file.read()
+        if driver_info.config_needed and not config:
+            logger.warning("Config needed, but no config file available")
+            return None
+
+        return cls(host, driver_info, firmware, config)
+
+    def __init__(self, host, driver_info, firmware, config):
+        self.host = weakref.proxy(host)
+        self.driver_info = driver_info
+        self.firmware = firmware
+        self.config = config
+
+    @staticmethod
+    async def drop_firmware(host):
+        host.send_hci_packet(HCI_RTK_Drop_Firmware_Command())
+
+        # Wait for the command to be effective (no response is sent)
+        await asyncio.sleep(Driver.POST_DROP_DELAY)
+
+    async def download_for_rtl8723a(self):
+        # Check that the firmware image does not include an epatch signature.
+        if RTK_EPATCH_SIGNATURE in self.firmware:
+            logger.warning(
+                "epatch signature found in firmware, it is probably the wrong firmware"
+            )
+            return
+
+        # TODO: load the firmware
+
+    async def download_for_rtl8723b(self):
+        if self.driver_info.has_rom_version:
+            response = await self.host.send_command(
+                HCI_RTK_Read_ROM_Version_Command(), check_result=True
+            )
+            if response.return_parameters.status != HCI_SUCCESS:
+                logger.warning("can't get ROM version")
+                return
+            rom_version = response.return_parameters.version
+            logger.debug(f"ROM version before download: {rom_version:04X}")
+        else:
+            rom_version = 0
+
+        firmware = Firmware(self.firmware)
+        logger.debug(f"firmware: project_id=0x{firmware.project_id:04X}")
+        for patch in firmware.patches:
+            if patch[0] == rom_version + 1:
+                logger.debug(f"using patch {patch[0]}")
+                break
+        else:
+            logger.warning("no valid patch found for rom version {rom_version}")
+            return
+
+        # Append the config if there is one.
+        if self.config:
+            payload = patch[1] + self.config
+        else:
+            payload = patch[1]
+
+        # Download the payload, one fragment at a time.
+        fragment_count = math.ceil(len(payload) / RTK_FRAGMENT_LENGTH)
+        for fragment_index in range(fragment_count):
+            # NOTE: the Linux driver somehow adds 1 to the index after it wraps around.
+            # That's odd, but we"ll do the same here.
+            download_index = fragment_index & 0x7F
+            if download_index >= 0x80:
+                download_index += 1
+            if fragment_index == fragment_count - 1:
+                download_index |= 0x80  # End marker.
+            fragment_offset = fragment_index * RTK_FRAGMENT_LENGTH
+            fragment = payload[fragment_offset : fragment_offset + RTK_FRAGMENT_LENGTH]
+            logger.debug(f"downloading fragment {fragment_index}")
+            await self.host.send_command(
+                HCI_RTK_Download_Command(
+                    index=download_index, payload=fragment, check_result=True
+                )
+            )
+
+        logger.debug("download complete!")
+
+        # Read the version again
+        response = await self.host.send_command(
+            HCI_RTK_Read_ROM_Version_Command(), check_result=True
+        )
+        if response.return_parameters.status != HCI_SUCCESS:
+            logger.warning("can't get ROM version")
+        else:
+            rom_version = response.return_parameters.version
+            logger.debug(f"ROM version after download: {rom_version:04X}")
+
+    async def download_firmware(self):
+        if self.driver_info.rom == RTK_ROM_LMP_8723A:
+            return await self.download_for_rtl8723a()
+
+        if self.driver_info.rom in (
+            RTK_ROM_LMP_8723B,
+            RTK_ROM_LMP_8821A,
+            RTK_ROM_LMP_8761A,
+            RTK_ROM_LMP_8822B,
+            RTK_ROM_LMP_8852A,
+        ):
+            return await self.download_for_rtl8723b()
+
+        raise ValueError("ROM not supported")
+
+    async def init_controller(self):
+        await self.download_firmware()
+        await self.host.send_command(HCI_Reset_Command(), check_result=True)
+        logger.info(f"loaded FW image {self.driver_info.fw_name}")

bumble/hci.py

@@ -1641,9 +1641,11 @@ class HCI_Object:
             # Get the value for the field
             value = hci_object[key]
 
-            # Map the value if needed
+            # Check if there's a matching mapper passed
             if value_mappers:
                 value_mapper = value_mappers.get(key, value_mapper)
+
+            # Map the value if we have a mapper
             if value_mapper is not None:
                 value = value_mapper(value)
 

bumble/host.py

@@ -23,6 +23,7 @@ import struct
 from bumble.colors import color
 from bumble.l2cap import L2CAP_PDU
 from bumble.snoop import Snooper
+from bumble import drivers
 
 from typing import Optional
 
@@ -116,6 +117,7 @@ class Host(AbortableEventEmitter):
         super().__init__()
 
         self.hci_sink = None
+        self.hci_metadata = None
         self.ready = False  # True when we can accept incoming packets
         self.reset_done = False
         self.connections = {}  # Connections, by connection handle
@@ -141,6 +143,9 @@ class Host(AbortableEventEmitter):
         # Connect to the source and sink if specified
         if controller_source:
             controller_source.set_packet_sink(self)
+            self.hci_metadata = getattr(
+                controller_source, 'metadata', self.hci_metadata
+            )
         if controller_sink:
             self.set_packet_sink(controller_sink)
 
@@ -170,7 +175,7 @@ class Host(AbortableEventEmitter):
         self.emit('flush')
         self.command_semaphore.release()
 
-    async def reset(self):
+    async def reset(self, raw=False):
         if self.ready:
             self.ready = False
             await self.flush()
@@ -178,6 +183,15 @@ class Host(AbortableEventEmitter):
         await self.send_command(HCI_Reset_Command(), check_result=True)
         self.ready = True
 
+        # Instantiate and init a driver for the host if needed.
+        # NOTE: we don't keep a reference to the driver here, because we don't
+        # currently have a need for the driver later on. But if the driver interface
+        # evolves, it may be required, then, to store a reference to the driver in
+        # an object property.
+        if not raw:
+            if (driver :=  await drivers.get_driver_for_host(self)):
+                await driver.init_controller()
+
         response = await self.send_command(
             HCI_Read_Local_Supported_Commands_Command(), check_result=True
         )
@@ -298,7 +312,7 @@ class Host(AbortableEventEmitter):
         if self.snooper:
             self.snooper.snoop(bytes(packet), Snooper.Direction.HOST_TO_CONTROLLER)
 
-        self.hci_sink.on_packet(packet.to_bytes())
+        self.hci_sink.on_packet(bytes(packet))
 
     async def send_command(self, command, check_result=False):
         logger.debug(f'{color("### HOST -> CONTROLLER", "blue")}: {command}')
@@ -350,7 +364,7 @@ class Host(AbortableEventEmitter):
         asyncio.create_task(send_command(command))
 
     def send_l2cap_pdu(self, connection_handle, cid, pdu):
-        l2cap_pdu = L2CAP_PDU(cid, pdu).to_bytes()
+        l2cap_pdu = bytes(L2CAP_PDU(cid, pdu))
 
         # Send the data to the controller via ACL packets
         bytes_remaining = len(l2cap_pdu)

bumble/transport/usb.py

@@ -206,10 +206,11 @@ async def open_usb_transport(spec):
                     logger.debug('OUT transfer likely already completed')
 
     class UsbPacketSource(asyncio.Protocol, ParserSource):
-        def __init__(self, context, device, acl_in, events_in):
+        def __init__(self, context, device, metadata, acl_in, events_in):
             super().__init__()
             self.context = context
             self.device = device
+            self.metadata = metadata
             self.acl_in = acl_in
             self.events_in = events_in
             self.loop = asyncio.get_running_loop()
@@ -510,6 +511,10 @@ async def open_usb_transport(spec):
             f'events_in=0x{events_in:02X}, '
         )
 
+        device_metadata = {
+            'vendor_id': found.getVendorID(),
+            'product_id': found.getProductID(),
+        }
         device = found.open()
 
         # Auto-detach the kernel driver if supported
@@ -535,7 +540,7 @@ async def open_usb_transport(spec):
             except usb1.USBError:
                 logger.warning('failed to set configuration')
 
-        source = UsbPacketSource(context, device, acl_in, events_in)
+        source = UsbPacketSource(context, device, device_metadata, acl_in, events_in)
         sink = UsbPacketSink(device, acl_out)
         return UsbTransport(context, device, interface, setting, source, sink)
     except usb1.USBError as error:

setup.cfg

@@ -24,7 +24,7 @@ url = https://github.com/google/bumble
 
 [options]
 python_requires = >=3.8
-packages = bumble, bumble.transport, bumble.profiles, bumble.apps, bumble.apps.link_relay, bumble.pandora
+packages = bumble, bumble.transport, bumble.drivers, bumble.profiles, bumble.apps, bumble.apps.link_relay, bumble.pandora
 package_dir =
     bumble = bumble
     bumble.apps = apps

utils/rtk_util.py

@@ -0,0 +1,159 @@
+# Copyright 2021-2022 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# -----------------------------------------------------------------------------
+# Imports
+# -----------------------------------------------------------------------------
+import logging
+import asyncio
+import os
+
+import click
+
+from bumble import transport
+from bumble.host import Host
+from bumble.drivers import rtk
+
+# -----------------------------------------------------------------------------
+# Logging
+# -----------------------------------------------------------------------------
+logger = logging.getLogger(__name__)
+
+
+# -----------------------------------------------------------------------------
+def do_parse(firmware_path):
+    with open(firmware_path, 'rb') as firmware_file:
+        firmware_data = firmware_file.read()
+        firmware = rtk.Firmware(firmware_data)
+        print(f'Firmware: version=0x{firmware.version:08X} project_id=0x{firmware.project_id:04X}')
+        for patch in firmware.patches:
+            print(
+                f"  Patch: chip_id=0x{patch[0]:04X}, "
+                f"{len(patch[1])} bytes, "
+                f"SVN Version={patch[2]:08X}"
+            )
+
+
+# -----------------------------------------------------------------------------
+async def do_load(usb_transport, force):
+    async with await transport.open_transport_or_link(usb_transport) as (
+        hci_source,
+        hci_sink,
+    ):
+        # Create a host to communicate with the device
+        host = Host(hci_source, hci_sink)
+        await host.reset(raw=True)
+
+        # Get the driver.
+        driver = await rtk.Driver.for_host(host, force)
+        if driver is None:
+            if not force:
+                print("Firmware already loaded or no supported driver for this device.")
+                return
+
+        await driver.download_firmware()
+
+
+# -----------------------------------------------------------------------------
+async def do_drop(usb_transport):
+    async with await transport.open_transport_or_link(usb_transport) as (
+        hci_source,
+        hci_sink,
+    ):
+        # Create a host to communicate with the device
+        host = Host(hci_source, hci_sink)
+        await host.reset(raw=True)
+
+        # Tell the device to reset/drop any loaded patch
+        await rtk.Driver.drop_firmware(host)
+
+
+# -----------------------------------------------------------------------------
+async def do_info(usb_transport, force):
+    async with await transport.open_transport(usb_transport) as (
+        hci_source,
+        hci_sink,
+    ):
+        # Create a host to communicate with the device
+        host = Host(hci_source, hci_sink)
+        await host.reset(raw=True)
+
+        # Check if this is a supported device.
+        if not force and not rtk.Driver.check(host):
+            print("USB device not supported by this RTK driver")
+            return
+
+        # Get the driver info.
+        driver_info = await rtk.Driver.driver_info_for_host(host)
+        if driver_info:
+            print(
+                "Driver:\n"
+                f"  ROM:      {driver_info.rom:04X}\n"
+                f"  Firmware: {driver_info.fw_name}\n"
+                f"  Config:   {driver_info.config_name}\n"
+            )
+        else:
+            print("Firmware already loaded or no supported driver for this device.")
+
+
+# -----------------------------------------------------------------------------
+@click.group()
+def main():
+    pass
+
+
+@main.command
+@click.argument("firmware_path")
+def parse(firmware_path):
+    """Parse a firmware image."""
+    do_parse(firmware_path)
+
+
+@main.command
+@click.argument("usb_transport")
+@click.option(
+    "--force",
+    is_flag=True,
+    default=False,
+    help="Load even if the USB info doesn't match",
+)
+def load(usb_transport, force):
+    """Load a firmware image into the USB dongle."""
+    asyncio.run(do_load(usb_transport, force))
+
+
+@main.command
+@click.argument("usb_transport")
+def drop(usb_transport):
+    """Drop a firmware image from the USB dongle."""
+    asyncio.run(do_drop(usb_transport))
+
+
+@main.command
+@click.argument("usb_transport")
+@click.option(
+    "--force",
+    is_flag=True,
+    default=False,
+    help="Try to get the device info even if the USB info doesn't match",
+)
+def info(usb_transport, force):
+    """Get the firmware info from a USB dongle."""
+    asyncio.run(do_info(usb_transport, force))
+
+
+# -----------------------------------------------------------------------------
+if __name__ == '__main__':
+    logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'INFO').upper())
+    main()