Update module names for T2 MacBook profiles

[simiscoool-afk]

No description provided.

[Revival8697]

Wrong module names. See https://github.com/deqrocks/t2bce#changes-compared-to-apple-bce.

[simiscoool-afk]

Thanks, i am quite new to this but trying to learn.

i have gotten some help from a user on the discord called several people, this should work i think, if there are any problems or anything i am happy to fix and learn.

[Revival8697]

Resolves CachyOS/linux-cachyos#1004.

CC: @vnepogodin.

[ventureoo]

I would like to create proper module alias configuration instead of force loading any modules.

[ventureoo]

alias pci:v0000106Bd00001801sv*sd*bc*sc*i* t2bce_core
alias pci:v0000106Bd00001801sv*sd*bc*sc*i* t2bce_dma
alias pci:v0000106Bd00001801sv*sd*bc*sc*i* t2bce_vhci
alias pci:v0000106Bd00001801sv*sd*bc*sc*i* t2bce_audio
alias pci:v0000106Bd00001802sv*sd*bc*sc*i* t2bce_core
alias pci:v0000106Bd00001802sv*sd*bc*sc*i* t2bce_dma
alias pci:v0000106Bd00001802sv*sd*bc*sc*i* t2bce_vhci
alias pci:v0000106Bd00001802sv*sd*bc*sc*i* t2bce_audio

[1Naim]

I would like to create proper module alias configuration instead of force loading any modules.

Those already exist for the new t2bce modules. I think the issue to solve now is how to fix the old file for existing installs once 6.18 also gets t2bce.

[PandaWood]

I think the issue to solve now is how to fix the old file for existing installs once 6.18 also gets t2bce.

Happy to leave this with you - I'm just a user who hit the break after 7.2 kernel upgrade...

But for what it's worth after following this, my AI suggested this for me:

a one-shot pacman hook in the chwd package that rewrites 11-chwd.conf on upgrade if it still references apple-bce. That way existing installs get fixed without users needing to do anything

If it's useful to have someone to test against, I'm on an iMac Pro

[yiminyuan]

This won't fix the issue. The installer also installs the LTS kernel, which does not ship the t2bce modules. As a result, this fix would still cause mkinitcpio to fail for the LTS kernel, potentially aborting the installation.

I think MODULES needs to be an empty array as long as LTS and mainline kernels ship different bce modules. After installation, we need to do cachy-chroot, remove one incompatible kernel, and manually do mkinitcpio before reboot.

The best way of fixing this issue is having an option to choose the kernel variants.

[Jsandwith00]

if the installer is the LTS kernel it should install then?
the installer is requesting Apple-BCE but cant find is which is suggesting that its not the LTS kernel or its newer than 7.1.x

[Revival8697]

Eh, just add t2bce to LTS then, no need to complicate this.

CC: @1Naim.

[yiminyuan]

I see that the installer installs both linux-cachyos (which migrated to t2bce in 7.2) and linux-cachyos-lts (which still uses apple-bce in 6.18) by default.

Therefore, changing to MODULES+=(t2bce_core t2bce_dma t2bce_vhci t2bce_audio) would probably cause mkinitcpio to fail for the linux-cachyos-lts kernel, potentially aborting the installation—similar to what is currently happening with linux-cachyos.

[PandaWood]

OK I admit a lot of help from Claude/Opus on this one, but here we go...

Data point from a T2 machine that isn't a MacBook — iMacPro1,1, chwd 1.24.1-1, with both linux-cachyos 7.2.3-1 and linux-cachyos-lts 6.18.48-1 installed.

@yiminyuan's concern about LTS is correct — here it is actually happening. I applied exactly the MODULES= list from this PR as a drop-in and ran mkinitcpio -P:

==> Starting build: '6.18.48-1-cachyos-lts'
==> ERROR: module not found: 't2bce_core'
==> ERROR: module not found: 't2bce_dma'
==> ERROR: module not found: 't2bce_vhci'
==> ERROR: module not found: 't2bce_audio'
==> WARNING: errors were encountered during the build. The image may not be complete.

==> Starting build: '7.2.3-1-cachyos'
==> Initcpio image generation successful

The error moves from mainline to LTS rather than going away, because mkinitcpio -P builds every preset from one shared config.

There is a middle option between "empty array" and "add t2bce to LTS", though: $KERNELVERSION is in scope when mkinitcpio sources the config, so the generated drop-in can pick per kernel and both presets build clean:

# /etc/mkinitcpio.conf.d/11-chwd.conf
_t2dir="/usr/lib/modules/${KERNELVERSION}/kernel/drivers/staging"
if [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/t2bce" ]; then
    MODULES+=(t2bce_vhci)
elif [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/apple-bce" ]; then
    MODULES+=(apple-bce)
fi
unset _t2dir

That keeps working through the transition without requiring anyone to remove a kernel or chroot after install.

On @ventureoo's alias suggestion — the aliases are already compiled into the modules, and the proposed IDs don't match them. From the 7.2.3 tree:

=== t2bce_core ===
softdep:  post: t2bce_vhci
depends:  t2bce_dma
alias:    pci:v0000106Bd00001801sv*sd*bc*sc*i*

=== t2bce_dma ===
depends:

=== t2bce_vhci ===
softdep:  pre: t2bce_core
depends:  t2bce_core

=== t2bce_audio ===
softdep:  pre: t2bce_core
depends:  snd,snd-pcm,t2bce_core
alias:    pci:v0000106Bd00001803sv*sd*bc*sc*i*

against the actual devices:

02:00.1 Apple Inc. T2 Bridge Controller [106b:1801]
02:00.2 Apple Inc. T2 Secure Enclave Processor [106b:1802]
02:00.3 Apple Inc. Apple Audio Device [106b:1803]

So t2bce_core autoloads from 1801 and pulls t2bce_dma (depends) and t2bce_vhci (softdep post); t2bce_audio autoloads separately from 1803. Nothing binds 1802. The block in the review comment maps all four modules onto 1801 and 1802, which would attach t2bce_audio to the wrong device and add aliases for two modules that are meant to arrive via depends/softdep.

The whole stack comes up with no configuration at all. On this machine /etc/modules-load.d/t2.conf has contained the stale apple-bce for months —

systemd-modules-load[394]: Failed to find module 'apple_bce'

— and until today there were no t2bce modules in the initramfs either, yet all four load correctly every boot:

t2bce_audio            77824  0
t2bce_vhci            106496  0
t2bce_core             53248  2 t2bce_audio,t2bce_vhci
t2bce_dma              36864  1 t2bce_core

That suggests the modules-load.d line can simply be dropped rather than renamed or replaced with aliases, leaving MODULES+= (for the initramfs) as the only part that actually needs deciding.

Caveat: this is an iMac Pro, where the keyboard is external and the T2 modules aren't needed to reach a LUKS prompt, so I can't confirm the initramfs side from here. Someone on a T2 MacBook that depends on the internal keyboard at unlock should check t2bce_vhci really lands in the image before the MODULES+= line is trimmed.

Separately, the current master still writes apple-bce in both places, so until this lands every T2 Mac gets a failed mkinitcpio hook on each kernel update and a Failed to find module on each boot.

[InsideTheVoid]

I have a T2 macbook with LUKS and need to manually set the module otherwise i can't use the internal keyboard or unlock my drive.

I'm running this workaround:

if [[ "$KERNELVERSION" =~ ^(6\.|7\.[01]) ]]; then
    MODULES+=(apple-bce)
else
    MODULES+=(t2bce_dma t2bce_core t2bce_vhci t2bce_audio)
fi

[PandaWood]

@InsideTheVoid thanks, that closes the gap in my comment.

A LUKS T2 MacBook that can't type without the modules in the image means the
MODULES+= line has to stay, so "empty array" isn't a general fix, and my "this
can probably be dropped" only applies to /etc/modules-load.d/t2.conf, not the
initramfs entry.

Also good to have $KERNELVERSION confirmed on a second machine.

One thing I'd change in the workaround: ^(6\.|7\.[01]) hardcodes where the
rename happened, so an LTS line moving to 7.x while still shipping apple-bce
(or a backport the other way) would silently pick the wrong name. Testing what
the kernel tree actually contains is self-correcting:

_t2dir="/usr/lib/modules/${KERNELVERSION}/kernel/drivers/staging"
if [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/t2bce" ]; then
    MODULES+=(t2bce_core t2bce_dma t2bce_vhci t2bce_audio)
elif [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/apple-bce" ]; then
    MODULES+=(apple-bce)
fi
unset _t2dir

Checked against mkinitcpio itself: KERNELVERSION is resolved before the main
config and the conf.d drop-ins are concatenated and sourced, so this works for
every preset in mkinitcpio -P and in the installer chroot, not just for the
running kernel.

@simiscoool-afk if you want to fold this into the PR, one gotcha: the profile
writes 11-chwd.conf through cat <<EOF, which expands variables when chwd
runs post_install, not when mkinitcpio later reads the file. It needs
cat <<'EOF' for the block above to survive intact. With that, both kernels
build clean and no chroot step is needed. Suggested diff against master:

 post_install = """
-    cat <<EOF >/etc/mkinitcpio.conf.d/11-chwd.conf
+    cat <<'EOF' >/etc/mkinitcpio.conf.d/11-chwd.conf
 # This file is automatically generated by chwd. PLEASE DO NOT EDIT IT.
-MODULES+=(apple-bce)
+# linux-cachyos >= 7.2 ships t2bce_*, linux-cachyos-lts still ships apple-bce.
+# Pick whichever exists for the kernel being built so `mkinitcpio -P` succeeds
+# for every installed preset.
+_t2dir="/usr/lib/modules/${KERNELVERSION}/kernel/drivers/staging"
+if [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/t2bce" ]; then
+    MODULES+=(t2bce_core t2bce_dma t2bce_vhci t2bce_audio)
+elif [ -n "${KERNELVERSION}" ] && [ -d "${_t2dir}/apple-bce" ]; then
+    MODULES+=(apple-bce)
+fi
+unset _t2dir
 EOF
     mkinitcpio -P

-    echo apple-bce > /etc/modules-load.d/t2.conf
+    # Both drivers autoload from their PCI aliases (106b:1801 / 106b:1803);
+    # remove the stale entry that fails systemd-modules-load on every boot.
+    rm -f /etc/modules-load.d/t2.conf
     kernelparams="intel_iommu=on iommu=pt pcie_ports=compat"

post_remove already deletes t2.conf, so nothing else needs to change there.