CachyOS Mac Pro 6,1 ISO — eonicman Fork

A fixed and maintained fork of wolffcatskyy/cachyos-macpro-iso (archived March 2026).

Custom CachyOS ISO for the Mac Pro 6,1 (Late 2013) — the "trash can" Mac — with full hardware support, GPU firmware, fan control, and macOS Tahoe KVM.

Why This Fork

The original project was archived with 6 critical bugs that made the ISO unbootable after installation. The kernel config is excellent; the ISO packaging and installer integration were broken. This fork fixes all 6 bugs:

Bug	Severity	Fix
Empty local-repo/ — kernel never enters ISO	🔴 Critical	Build scripts + repo setup automation
EFI boot entries missing custom kernel	🟡 Medium	Added 03-archiso-linux-macpro61.conf + fallback
Initramfs references without initramfs	🟡 Medium	Added mkinitcpio config + minimal initramfs
No macfanctld / no applesmc in fallback	🔴 Critical	Added macfanctld + applesmc module-load + fan service
SSH not enabled / UFW blocks port 22	🟡 Medium	Enabled sshd + UFW SSH rule
Calamares pacstrap installs wrong kernel	🔴 Critical	Post-install chroot script swaps kernels, configures boot

See FIXES.md for detailed analysis.

What You Get

• CachyOS KDE Plasma desktop with 17+ DE options via installer
• Custom linux-macpro61 kernel with:
  • AMD FirePro D300/D500/D700 GPU firmware embedded (amdgpu SI support)
  • All critical drivers built-in (=y) — no initramfs needed for basic boot
  • BORE CPU scheduler + BBR3 congestion control
  • ACPI GPE16 storm fix (Thunderbolt log spam eliminated)
  • NVMe + TRIM support out of the box
  • KVM built-in for macOS Tahoe virtualization
• Fan control — applesmc + macfanctld for thermal management
• Cold boot protection — reboot aliased to poweroff, reboot.target masked
• SSH enabled in live environment for headless setup
• Post-install script that fixes the kernel, boot entries, and hardware config

Quick Start

Download the ISO

Download the latest release from GitHub Releases.

Flash to USB

# Linux/macOS
sudo dd if=cachyos-macpro-*.iso of=/dev/sdX bs=4M status=progress && sync

# Or use balenaEtcher / Rufus (Windows)

Boot your Mac Pro

1. Power off the Mac Pro (never reboot — GPU firmware only initializes on cold boot)
2. Press the power button and immediately hold the Option key
3. Select the USB drive
4. Choose "CachyOS (Mac Pro 6,1)" from the GRUB menu
5. Desktop loads — double-click the installer icon

⚠️ After Install: Always Power Off

The Mac Pro 6,1 has an Apple EFI quirk: the GPU only initializes on cold boot. After installation:

sudo poweroff    # NOT reboot!
# Then press the power button

Build the ISO Yourself

You need an Arch Linux or CachyOS machine (can be the Mac Pro itself).

Step 1: Clone both repos

git clone https://github.com/eonicman/linux-mac.git
git clone https://github.com/eonicman/cachyos-macpro-iso.git
cd cachyos-macpro-iso

Step 2: Build the kernel

./scripts/build-kernel.sh /path/to/linux-mac
# Takes 30-90 min on a Mac Pro

Step 3: Set up the local repo

./scripts/setup-local-repo.sh

Step 4: Build the ISO

sudo pacman -S archiso mkinitcpio-archiso squashfs-tools grub --needed
sudo pacman-key --recv-keys 882DCFE48E2051D48E2562ABF3B607488DB35A47
sudo pacman-key --lsign-key 882DCFE48E2051D48E2562ABF3B607488DB35A47
./scripts/build-iso.sh -v

macOS Tahoe KVM

The kernel has KVM built-in. See docs/kvm-macos.md for running macOS Tahoe in a VM with ~2-5% CPU overhead.

Current state: Phase 1 (software-rendered QXL display) — usable for CLI and light desktop work. Phase 3 (GPU passthrough via PVG) is on the roadmap in linux-mac/docs/pvg-linux.md.

Hardware Support

Feature	Status	Notes
GPU (D300/D500/D700)	✅ Working	amdgpu built-in, radeonsi/RADV via Mesa
Display (DP/HDMI)	✅ Working	Via amdgpu + DC
Vulkan / OpenGL	✅ Working	Mesa RADV / radeonsi
Ethernet (both ports)	✅ Working	tg3 + Broadcom PHY built-in
Wi-Fi	⚠️ Proprietary	broadcom-wl-dkms (AUR)
Audio	✅ Working	Intel HDA + Cirrus CS4208 (model=macpro6 inv_jack_detect=1)
USB 3.0	✅ Working	xHCI built-in
Thunderbolt 2	⚠️ Partial	Works with log spam (GPE16 masked)
NVMe + TRIM	✅ Working	Built-in; enable fstrim.timer
Bluetooth	✅ Working	Broadcom via btusb
Fan Control	✅ Working	applesmc + macfanctld
KVM (macOS Tahoe)	✅ Working	~2-5% CPU overhead
Sleep/Wake	❌ Disabled	Unreliable on this hardware

Audio Fix (v2)

The Mac Pro 6,1 uses a Cirrus Logic CS4208 audio codec behind an Intel C600/X79 HDA controller. The generic snd_hda_intel driver doesn't apply the correct pin layout, so internal speakers and headphone jack are silent.

Fix: Two config files injected into the ISO's airootfs:

• modprobe.d/macpro-audio.conf — forces model=macpro6 pin layout + inv_jack_detect=1 (fixes phantom headphone detection that mutes internal speakers)
• modules-load.d/macpro-sound.conf — loads snd-hda-codec-cirrus codec module

Critical: After applying or changing audio config, you must cold shutdown (sudo poweroff), not reboot. The Mac Pro 6,1 EFI doesn't reset audio power lanes on warm reboot.

What's Changed from the Original

Area	Change
modprobe.d/macpro-audio.conf	NEW — Mac Pro 6,1 audio pin layout + jack detect fix
modules-load.d/macpro-sound.conf	NEW — Load Cirrus Logic CS4208 codec module
local-repo/	Build scripts to populate with kernel packages
packages_desktop.x86_64	Added macfanctld
EFI boot entries	Added 03-macpro61.conf + 04-macpro61-fallback.conf
systemd/system/	Added sshd.service, macpro-fancontrol.service, applesmc_load.service
modules-load.d/	Added applesmc.conf
ufw/applications.d/	Added SSH UFW rule
Post-install	macpro-postinstall.sh — swaps kernel, configures boot, fan control
Installer wrapper	macpro-installer-launch.sh — runs Calamares then applies fixes
profiledef.sh	Added new scripts to file_permissions
Build scripts	scripts/build-kernel.sh, setup-local-repo.sh, build-iso.sh

Testing Checklist

• ISO boots to desktop with Mac Pro kernel (GRUB entry 1)
• applesmc loaded, fans audible (sensors | grep applesmc)
• macfanctld running (systemctl status macfanctld)
• GPU detected (lspci | grep AMD, glxinfo | grep renderer)
• SSH accessible from another machine
• reboot command warns and powers off instead
• Calamares installer runs successfully
• Installed system boots with linux-macpro61 kernel
• Installed system has macfanctld, no-reboot alias, ESP sync hook
• pacman -Syu can update from [macpro] repo
• Cold boot (poweroff + power on) restores GPU
• Audio works (internal speakers + headphone jack)
• alsamixer shows HDA Intel PCH with unmuted controls
• Warm reboot produces warning and powers off

Credits

• wolffcatskyy — original kernel config, hardware audit, KVM docs, and ISO framework
• CachyOS — base ISO builder and optimized packages
• linux-mac — custom kernel for Mac Pro 6,1

License

GPL-2.0 (same as the Linux kernel)