Dennis HilkLinux diagnosticsDE

Bluetooth

Broadcom Bluetooth UART family context

A Broadcom serial Bluetooth family context using board power/reset resources and optional PatchRAM. USB Bluetooth matching does not identify this UART path.

Editorial source review: Share public profileOpen in the identification tool
On this page
  1. Overview & identity
  2. Driver & binding
  3. Firmware
  4. Read-only diagnostics
  5. Limitations & related issues
  6. References

Overview & identity

The reviewed path matches ACPI or device-tree board descriptions. No PCI/USB pair or unique Raspberry Pi/laptop model is assigned to this generic profile.

This is an explicit class, transport or driver-context profile. It is not an exact numeric product match.

A numeric match establishes a candidate family within the reviewed evidence. Marketing names, board variants, subsystem conditions and successful operation remain separate questions.

Driver & binding

hci_bcm is compiled into hci_uart; btbcm supplies Broadcom controller and HCD-patch helpers. The board’s reset, clock and power resources affect initialization independently of BlueZ.

  • hci_uart — kernel driver/module candidate
  • btbcm — kernel driver/module candidate

Detected, bound, operational: learn the difference

Firmware

Conditional firmware path

The helper chooses HCD names from controller and platform information. Firmware can be optional in some paths; use the exact requests and setup result from the host.

Checked examples or filename branches, not a complete installation list:

  • brcm/*.hcd

Inspect firmware packaging on your distribution

Read-only diagnostics

Run one displayed command at a time. Replace uppercase placeholders with the affected device, interface or module from your own output. Commands are never executed here. Read-only output can still contain private identifiers.

Read the controller parent path

readlink -f /sys/class/bluetooth/CONTROLLER/device

Replace CONTROLLER with the local hci name, such as hci0, found in /sys/class/bluetooth. The path helps distinguish USB, serial and SDIO parents. It does not prove which UART protocol is active. No root privileges are needed.

Read controllers visible to BlueZ

bluetoothctl list

This asks the BlueZ daemon for known controllers without discovery or pairing. An empty response can mean daemon or D-Bus access problems as well as absent controllers; compare kernel enumeration. Normally no root privileges are needed.

Read controller initialization

journalctl -k -b --no-pager

Read the current boot’s kernel messages for the controller, requested firmware and setup result. Journal visibility depends on local permissions; an unreadable log is not evidence of no errors. This command does not change the device.

Limitations & related issues

A brcm HCD filename for a USB product is not automatically suitable for a UART board. This class context cannot tell which board-specific suffix the host selected.

These guides are linked for relevant observations, not as known defects of every device in this family.

Choose a hardware diagnostic workflow · Inspect a log excerpt in Fix Lab

References

Source review records a checked implementation or document, not a reproduced hardware test. Version-specific tables do not establish a minimum kernel or guaranteed operation.