UBTBCMFW(4)

📦 version 12.2, in debian bookworm, debian trixie, ubuntu jammy, ubuntu noble, ubuntu questing, ubuntu resolute, ubuntu stonking

💖 UBTBCMFW — the firmware driver glow-up (section 4 of the Kernel Interfaces Manual, bestie) 💖

okay so picture this: it's the Kernel Interfaces Manual, and this page is about a lil driver called ubtbcmfw. say it with me: u-b-t-b-c-m-f-w. it's giving "acronym that ate" but we move. 🦋

✨ NAME ✨

ubtbcmfw — the Firmware driver for Broadcom BCM2033 chip based Bluetooth USB devices 🎀

like. it is literally the firmware driver. for Broadcom BCM2033 chip based Bluetooth USB devices. no notes. 👑

🌸 SYNOPSIS 🌸

so there's two ways to get this baby into your life, and both are giving "pick your fighter".

Option A — bake it into the kernel. drop this line into your kernel configuration file:

device ubtbcmfw

Option B — load it as a module at boot time. for that one, this line goes in loader.conf(5):

ubtbcmfw_load="YES"

that's it. that's the whole vibe check. ✨

💅 DESCRIPTION 💅

okay so ubtbcmfw is a firmware driver for Broadcom BCM2033 chip based Bluetooth USB devices. and what does it actually do? it gives you minimal access to the parts of the device required to download firmware. minimal. it's not doing the most, it's doing exactly enough, and honestly? respect. 🙈

the ubtbcmfw driver creates three fixed endpoint device nodes. three. fixed. endpoint. device. nodes. remember that number, bestie, it comes back. 💖

now let's get into the endpoints themselves, because each one has rules:

  • control transfers can only happen on the control endpoint, which is always endpoint 0. and the way you issue control requests? ioctl(2) calls. that's the whole door. 🚪
  • on an interrupt endpoint, only incoming transfers are supported. to do I/O on an interrupt endpoint you use read(2). all I/O operations on an interrupt endpoint are unbuffered. and the interrupt endpoint is always endpoint 1. no cap. ✨
  • on a bulk endpoint, only outgoing bulk transfers are supported. to do I/O on a bulk endpoint you use write(2). all I/O operations on a bulk endpoint are unbuffered. and the outgoing bulk endpoint is always endpoint 2. periodt. 💅

and the control endpoint (endpoint 0, the main character, the one with the control transfers) handles the following ioctl(2) calls:

  • USB_GET_DEVICE_DESC (usb_device_descriptor_t) — returns the device descriptor. that's it, that's the call, and yes the type is usb_device_descriptor_t, we do not abbreviate. 🎀

🎀 FILES 🎀

  • /dev/ubtbcmfwN.EE — Endpoint EE of device N. (see? told you the nodes come back. N is the device, EE is the endpoint, and it's all very tidy.) 🌸

🌈 SEE ALSO 🌈

go read your other faves, bestie, they're all linked up:

the friend group is stacked. 🫶

⭐ HISTORY ⭐

the ubtbcmfw driver was implemented in FreeBSD 5.0. an icon, a legend, and it is the moment. 👑

💜 AUTHORS 💜

Maksim Yevmenkin <m_evmenkin@yahoo.com> — thank you for your service, king. 🫡✨

💀 BUGS 💀

"Most likely. Please report if found."

that's it. that's the entire bugs section. the most unbothered, most honest, most iconic bug report of all time. if you find one, please report it. the driver is not going to pretend it's perfect. 😭

ngl bestie, if you're poking at endpoint 0, 1, or 2 and something goes weird — say something. the manpage is literally begging you. 🙈

Debian · November 22, 2006 — that's the source, that's the date, and that's the sign-off. bye bestie, slay your USB stack 💖🎀🦋

📦 where this page comes from