galaxy book5 sensors on linux

November 16, 2024

After sorting out the whole issue of bluetooth firmware on my laptop, my next target was the integrated sensor hub (ISH). The ISH is an Intel-designed component that polls sensors automatically and makes getting their data much easier for the OS. Or something along those lines — either way, getting this hub working would mean that the lid sensor and accelerometer would be usable, and so tablet mode should “just work” in KDE.

Investigation

Looking through lspci, I saw that the driver was already loaded:

00:12.0 Serial controller [0700]: Intel Corporation Lunar Lake-M Integrated Sensor Hub [8086:a845] (rev 10)
        DeviceName: Onboard - Other
        Subsystem: Samsung Electronics Co Ltd Device [144d:c1da]
        Kernel driver in use: intel_ish_ipc
        Kernel modules: 8250_pci, intel_ish_ipc

This was pretty weird because nothing was showing up in /sys/bus/iio, where the sensors should be if they were accessible. In the kernel logs, it was clear that the driver wasn’t working right:

[    4.416718] intel_ish_ipc 0000:00:12.0: ISH loader: load firmware:  intel/ish/ish_lnlm.bin
[    4.430675] intel_ish_ipc 0000:00:12.0: ISH loader: cmd 2 failed 10
[    4.448263] intel_ish_ipc 0000:00:12.0: ISH loader: cmd 2 failed 10
[    4.467844] intel_ish_ipc 0000:00:12.0: ISH loader: cmd 2 failed 10

The documentation for ISH kernel driver shows that it should “just work” out of box, as long as the OEM didn’t create custom ISH firmware which wasn’t upstreamed. I didn’t think this was the case as on Windows, the driver shown in Device Manager was just the stock Intel one, with nothing indicating Samsung modifications.

At this point, I decided to email the maintainers of the intel-ish-ipc driver, and I got a response the next day! (Once I remembered to actually CC them on the mailing list, that is.) The maintainer explained that the hub probably needed Samsung’s custom firmware, which confused me for a bit considering I didn’t see how it could be provided on Windows, where the sensors were clearly working fine.

Search

After digging a little bit through the C:\Windows folder, I found a driver called IshHeciExtensionTemplate which had a FwImage folder! This didn’t show up in Device Manager at all, which is why I missed it on my first look. Notably, the firmware image in this folder was only around 650 KiB, instead of the 975 KiB image which the main driver and linux-firmware provided. The INF file made it clear that it was a Samsung extension, with this section:

[Strings]
; Needed changes: Specify your vendor name here
ManufacturerName="Samsung Electronics Co., Ltd."
VendorName = "Samsung Electronics Co., Ltd."

I brought the driver folder over to linux, and got to work trying to load it. The ISH driver docs explain how it looks for the right firmware to load, which is just picking the first file that exists in this list:

intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}_${PRODUCT_SKU_CRC32}.bin
intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_SKU_CRC32}.bin
intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}_${PRODUCT_NAME_CRC32}.bin
intel/ish/ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}.bin
intel/ish/ish_${intel_plat_gen}.bin

The only ISH firmware in the upstream linux-firmware repo was ish_lnlm.bin, so inserting the firmware as ish_${intel_plat_gen}_${SYS_VENDOR_CRC32}.bin should be enough to get it to load. I got the vendor string from /sys/class/dmi/id/sys_vendor, which was the same SAMSUNG ELECTRONICS CO., LTD. as from the Windows driver, passed it through some online CRC32 site, and dropped the new firmware into my linux-firmware package as intel/ish/ish_lnlm_053dca6a.bin.

One reboot later, and I saw iio-sensor-proxy was actually running, and tablet mode/screen rotation was fully working! I was kinda surprised that it worked first try.

Publish

The only issue left was getting this into the hands of others who need it. Unfortunately, Samsung doesn’t care at all about linux support, so unlike with the bluetooth firmware, I couldn’t just wait for the vendor to publish to linux-firmware later.

On top of that, the firmware is completely unlicensed, apart from the big INTEL PROPRIETARY header in the INF file, which is probably just a leftover from the messily edited template file. And without a license, it can’t be assumed to be redistributable and certainly won’t be accepted to linux-firmware if I submitted it myself.

The Microsoft Update Catalog has the following to say about the license terms:

What are the legal terms for using Microsoft Update Catalog?

Your use of the Microsoft Update Catalog is subject to the Terms of Use. Software updates you receive through the Microsoft Update Catalog are governed by any license terms that come with them. If no license terms come with them, they may be governed by the original license agreement for the software to which they apply. You should check that license agreement for details.

Both the “any license terms that come with them” and “original license agreement for the software to which they apply” here seem to point to the “INTEL PROPRIETARY” license information, which explicitly forbids any kind of redistribution without written permission from Intel:

;*******************************************************************************
;*                                                                            **
;*                     I N T E L   P R O P R I E T A R Y                      **
;*                                                                            **
;*   COPYRIGHT (c) 2012-2024 BY INTEL CORPORATION. ALL RIGHTS RESERVED.  NO   **
;*   PART  OF  THIS  PROGRAM OR PUBLICATION MAY BE REPRODUCED, TRANSMITTED,   **
;*   TRANSCRIBED, STORED IN A RETRIEVAL  SYSTEM,  OR  TRANSLATED  INTO  ANY   **
;*   LANGUAGE OR COMPUTER LANGUAGE IN ANY FORM OR BY ANY MEANS, ELECTRONIC,   **
;*   MECHANICAL, MAGNETIC, OPTICAL, CHEMICAL, MANUAL, OR OTHERWISE, WITHOUT   **
;*   THE PRIOR WRITTEN PERMISSION OF :                                        **
;*                                                                            **
;*                             INTEL CORPORATION                              **
;*                                                                            **
;*                          2200 MISSION COLLEGE BLVD                         **
;*                                                                            **
;*                     SANTA CLARA, CALIFORNIA 95052-8119                     **
;*                                                                            **
;*******************************************************************************

If someone wants to try writing them a letter, be sure to tell me how it goes…

Do It Yourself

Thankfully for any other linux-using Book5 owners, as long as you still have a windows partition or the 19GB OEM recovery partition, the firmware is easy to get and install. It’s located in the folder /Windows/System32/DriverStore/FileRepository/ishheciextensiontemplate.inf_amd64_????????????????/FwImage/0003/ (where 0003 indicates the Lunar Lake platform).

The unknown part is a semi-random hex value, probably the Windows Update version identifier for the driver, and was 29445c37f90c085b on my recovery image, and f5d3f42bdf58e17b on my main installation. In the 0003 folder, there should be a file named something like ishS_SI_5.8.0.7720.bin (or the older version 7718 on the recovery environment).

Install that file into your /lib/firmware folder as intel/ish/ish_lnlm_053dca6a.bin and the sensors should Just Work on next boot. For some reason unloading and inserting the kernel module doesn’t work, a full reboot is needed.

Easy enough to do on NixOS:

  nixpkgs.overlays = [
    (final: prev: {
      linux-firmware = prev.linux-firmware.overrideAttrs (old: {
        postInstall = ''
          cp ${./ishS_SI_5.8.0.7720.bin} $out/lib/firmware/intel/ish/ish_lnlm_053dca6a.bin
        '';
      });
    })
  ];

#nixos