Introduction¶

This page explains how to perform a basic set up after installing Linux on a T2 Mac.

Do you need to do this?¶

This guide is mainly relevent in the following cases :

If you have installed Linux using an official ISO, instead of a T2 ISO.
The Make modules load on early boot section is relevant for those who wish to encrypt their disk drives using LUKS or some other similar software.
If some functionality related to T2 Macs is broken, then you can consider following this guide.

In rest cases, you probably won't need to follow this guide.

If you have used a T2 ISO, make sure you have followed the distro specific guide for your distro before continuing further.

Installing a kernel for T2 support¶

Installing a kernel with support for T2 Macs is required in order to get the Keyboard, Trackpad, Touch Bar, Audio, Fan and Wi-Fi working.

Many distro maintainers provide compiled kernels which can be installed on your Linux installation. Following are the links to the repos providing such kernels:

Linux Distribution	Kernel with T2 support
Arch based distros	https://github.com/NoaHimesaka1873/linux-t2-arch
Fedora	https://github.com/t2linux/fedora-kernel
Gentoo	https://github.com/t2linux/T2-Gentoo-Kernel
Manjaro	https://github.com/NoaHimesaka1873/manjaro-kernel-t2
NixOS	https://github.com/NixOS/nixos-hardware
Ubuntu based distros	https://github.com/t2linux/T2-Debian-and-Ubuntu-Kernel
Debian based distros	https://github.com/t2linux/T2-Debian-and-Ubuntu-Kernel
Debian based distros	https://github.com/andersfugmann/T2-Debian-Kernel

If compiled kernels for your distro are not available, then you shall have to compile a kernel on your own. You can follow the Kernel guide for help.

Add necessary kernel paramaters¶

Using your bootloader, add the intel_iommu=on iommu=pt pcie_ports=compat kernel parameters. For example in GRUB:

Edit /etc/default/grub.
On the line with GRUB_CMDLINE_LINUX="quiet splash", add the following kernel parameters: intel_iommu=on iommu=pt pcie_ports=compat.
Run sudo grub-mkconfig -o /boot/grub/grub.cfg if you are on a non-debian based distro. If using Debian or Ubuntu based distro, run sudo update-grub.

Make modules load on boot¶

Simply run the following:

echo apple-bce | sudo tee /etc/modules-load.d/t2.conf

Make modules load on early boot¶

Having the apple-bce module loaded early allows the use of the keyboard for decrypting encrypted volumes (LUKS). It also is useful when boot doesn't work, and the keyboard is required for debugging. To do this, one must ensure the apple-bce module as well as its dependent modules are included in the initial ram disk. You can get the list of dependent modules by running modinfo -F depends apple-bce The steps to be followed vary depending upon the initramfs module loading mechanism used by your distro. Some examples are given as follows:

On systems with initramfs-tools (all debian-based distros):

Run sudo su to open a shell as root.

Run the following over there:

cat <<EOF >> /etc/initramfs-tools/modules
# Required modules for getting the built-in apple keyboard to work:
snd
snd_pcm
apple-bce
EOF
update-initramfs -u

On systems with mkinitcpio (Commonly used on Arch):
1. Edit the /etc/mkinitcpio.conf file.
2. Ensure that the file has the following:
```
MODULES="apple-bce"
```
3. Run sudo mkinitcpio -P.
On systems with dracut (Commonly used on EndeavourOS and Fedora):
1. Run the following to create a dracut configuration file which loads the apple-bce module on early boot:
```
echo "force_drivers+=\" apple-bce \"" | sudo tee /etc/dracut.conf.d/t2linux-modules.conf
```
2. Run sudo dracut --force to regenerate the initramfs with this change.
On systems with other initramfs/initrd generation systems:

In this case, refer to the documentation of the same and ensure the kernel module apple-bce is loaded early.

Adding support for customisable Touch Bar¶

By default the Touch Bar works in the same mode which Windows Bootcamp uses on Linux. If you want to customise it, you can install tiny-dfr on your distro.

If you are using an Ubuntu or Debian based distro:

Add the apt repo for T2 Macs from here.
Install tiny-dfr by running sudo apt install tiny-dfr.
Restart your Mac.

If you are using Arch Linux or EndeavourOS:

Install tiny-dfr by running sudo pacman -Syu tiny-dfr.
Restart your Mac.

If you are using Fedora:

Install tiny-dfr with sudo dnf install rust-tiny-dfr.
Restart your mac

For other distros:

Compile tiny-dfr yourself if your distro don't have that packaged yet.

In order to make changes to the config for tiny-dfr, copy /usr/share/tiny-dfr/config.toml to /etc/tiny-dfr/config.toml and edit /etc/tiny-dfr/config.toml by following the instructions given in that file.

Change default touchbar mode without tiny-dfr¶

Run the following command, replacing 1 with the number corresponding to the desired touchbar mode.

Number	Default	Fn
0	Escape key	Ignore
1	Function	Media
2	Media	Functin

cat <<EOF | sudo tee /etc/modprobe.d/tb.conf
options hid-appletb-kbd mode=1
#         Change this number ^
EOF
sudo modprobe -r hid-appletb-kbd
sudo modprobe hid-appletb-kbd

NixOS

If you use NixOS, instead of running the command, add the following to your configuration. Modify mode=1 to your desired value.

{...}: {
  boot.extraModprobeConfig = ''
    options hid-appletb-kbd mode=1
    #         Change this number ^
  '';
}

Wi-Fi and Bluetooth¶

The drivers for Wi-Fi and Bluetooth are included in a kernel with T2 support. But, we also need firmware to get them working from macOS.

Instructions for the same are given in the Wi-Fi and Bluetooth guide.

Network Manager recurrent notifications¶

Some users have experienced recurrent notifications due the internal usb ethernet interface connected to the T2 chip. To avoid those notifications we can blacklist cdc_ncm and cdc_mbim modules with the following command:

sudo sh -c 'echo "# Disable for now T2 chip internal usb ethernet
blacklist cdc_ncm
blacklist cdc_mbim" >> /etc/modprobe.d/blacklist.conf'

Please note that this internal ethernet interface is required for various services including touchid that there currently is no Linux support for. In the future, if any of these services are supported, you'll need to undo this.

Suspend Workaround¶

Fedora and Arch based distros¶

S3 suspend has been broken since macOS Sonoma, it has never been fixed, but this workaround will make deep suspend work. Currently this workaround works only on Arch based distros and Fedora.

Create and edit this file: /etc/systemd/system/suspend-fix-t2.service
Check your modprobe and rmmod location by running:
```
which modprobe
which rmmod
```

Taking the example as /usr/bin for location of modprobe and rmmod, copy the following to /etc/systemd/system/suspend-fix-t2.service. If the location is different, do the changes accordingly.

[Unit]
Description=Disable and Re-Enable Apple BCE Module (and Wi-Fi)
Before=sleep.target
StopWhenUnneeded=yes

[Service]
User=root
Type=oneshot
RemainAfterExit=yes

#ExecStart=/usr/bin/modprobe -r brcmfmac_wcc
#ExecStart=/usr/bin/modprobe -r brcmfmac
ExecStart=/usr/bin/rmmod -f apple-bce

ExecStop=/usr/bin/modprobe apple-bce
#ExecStop=/usr/bin/modprobe brcmfmac
#ExecStop=/usr/bin/modprobe brcmfmac_wcc

[Install]
WantedBy=sleep.target

Enable the service by running: sudo systemctl enable suspend-fix-t2.service
If you are facing issues with Wi-Fi on resume, uncomment the lines having brcmfmac and brcmfmac_wcc in the above file.

Note

Make sure you have CONFIG_MODULE_FORCE_UNLOAD=y in the kernel config. To check, run: zcat /proc/config.gz | grep "CONFIG_MODULE_FORCE_UNLOAD" on Arch based distros, or grep "CONFIG_MODULE_FORCE_UNLOAD" /boot/config-$(uname -r) on Fedora.

Gentoo/OpenRC¶

S3 suspend has been broken since macOS Sonoma, it has never been fixed, but this workaround will make deep suspend work on Gentoo Linux using OpenRC and elogind.

Prerequisites:

Make sure elogind is installed and running:

rc-update add elogind boot
rc-service elogind start

For T2 MacBooks, while unloading only the apple-bce module is sufficient for basic suspend functionality, additional module handling may be required depending on your model:

All T2 models require the apple-bce module handling.
For models with Touch Bar, a specific module sequence (apple_bce -> hid_appletb_bl -> hid_appletb_kbd) is required to properly reinitialize the Touch Bar device after resume.
If you use tiny-dfr for Touch Bar customization, the tiny-dfr service needs to be stopped before suspend and started after resume, and appletbdrm module is required.

The script below includes all cases with commented sections. Uncomment the relevant sections based on your model and requirements. The loading order of modules is important for proper device initialization after resume.

Create and edit this file: /etc/elogind/system-sleep/apple-bce-handler

#!/bin/bash
case $1/$2 in
  pre/*)
    # Required for all T2 models
    rmmod -f apple_bce

    # Uncomment the following if using tiny dfr for touchbar
    #/etc/init.d/tiny-dfr stop
    #modprobe -r appletbdrm

    # Uncomment the following for models with touchbar, irrespective of whether using tiny-dfr
    #modprobe -r hid_appletb_kbd
    #modprobe -r hid_appletb_bl
    ;;

  post/*)
    # Required for all T2 models
    sleep 4 
    modprobe apple_bce

    # Uncomment the following for models with touchbar, irrespective of whether using tiny-dfr
    #sleep 4
    #modprobe hid_appletb_bl
    #sleep 2
    #modprobe hid_appletb_kbd

    # Uncomment the following if using tiny dfr for touchbar
    #sleep 2
    #modprobe appletbdrm
    #sleep 3
    #/etc/init.d/tiny-dfr start
    ;;
esac

Make the script executable:

chmod +x /etc/elogind/system-sleep/apple-bce-handler

Note

Make sure you have CONFIG_MODULE_FORCE_UNLOAD=y in the kernel config.