InstallingDebianOn/Apple/MacPro/1-1 wiki

Some basics for the moment

Debian 9 32-bit EFI enabled install: Confirmed and working
Debian 9 64-bit EFI enabled install: Fails to load installer

I have used these two intall images:
Network Install
xfce Live Install

Partitioning:
You can keep the already present EFI partition and delete the other
hfs+ partitions or select "Guided - use entire disk" and auto create
your partitions. I have used both options with success

Graphics Cards:
Apple Nvidia 7300GT, Tested & works, Proprietary driver, nvidia-legacy-304xx-driver
Apple Nvidia Quadro FX4500, Tested & works, Proprietary driver, nvidia-legacy-304xx-driver
Apple ATI X1900XT, Tested & works. No proprietary driver available is Stretch.

Networking:
Intel Corporation 80003ES2LAN Gigabit Ethernet Controller: Works during install
Broadcom Limited BCM4322 802.11a/b/g/n Wireless LAN Controller: Works after installing
firmware-b43-installer, b43-fwcutter