Virtio for Classic

QEMU is a good way to experiment with the "Classic" Mac OS. The Virtio devices make it even more fun to use!

Building

The Retro68 compilers are used. (Make sure that your checkout is from 2023-12-16 or later -- there was an important bugfix.)

Update your $PATH to include the Retro68 toolchain (powerpc-apple-macos-gcc etc).

Then:

git clone https://github.com/elliotnunn/classicvirtio.git
cd classicvirtio
make

Command-line args for qemu-system-ppc

-device loader,addr=0x4000000,file=/PATH/TO/classicvirtio/build/ndrv/ndrvloader
-prom-env "boot-command=init-program go"

Command-line args for qemu-system-m68k

-device nubus-virtio-mmio,romfile=/PATH/TO/classicvirtio/build/classic/declrom

Tablet input

Lets the mouse cursor move seamlessly in and out of the virtual machine window

• bug: scroll wheel support unreliable, and on Mac OS 9 only

PowerPC: works out of the box

-device virtio-tablet-pci

68k: requires virtio-mmio patch to QEMU

-device virtio-tablet-device

Disk driver

Lets QEMU use unpartitioned disk images, like Basilisk II or Mini vMac

• bug: read-only
• bug: freezes on PowerPC

PowerPC: not working yet 68k: works out of the box

-blockdev driver=file,read-only=on,node-name=FOO,filename=DISK.IMG
-device virtio-blk,drive=FOO

9P device

Presents a folder on the host computer as a bootable hard drive on the guest computer

• resource forks in *.rdump and type/creator codes in *.idump
• append _1 to mount_tag to use the native fork format on a macOS host (needs patches)
• bug: some filesystem operations (e.g. CatMove) unimplemented
• bug: booting qemu-system-m68k requires hacks to PRAM

PowerPC: works out of the box

-device virtio-9p-pci,fsdev=UNIQUENAME,mount_tag="Macintosh HD"
-fsdev local,id=UNIQUENAME,security_model=none,path=/PATH/TO/HOST/FOLDER
# Use this option to boot from the device:
-device loader,addr=0x4400000,file="/PATH/TO/HOST/FOLDER/System Folder/Mac OS ROM"

68k: requires virtio-mmio patch to QEMU

-device virtio-9p-device,fsdev=UNIQUENAME,mount_tag="Macintosh HD"
-fsdev local,id=UNIQUENAME,security_model=none,path=/PATH/TO/HOST/FOLDER

GPU

Removed in favour of SolraBizna's QFB work in progress

Might be brought back in future as a 3D coprocessor, but not a display device

Debug output

Append the following to your QEMU command line:

-device virtio-serial -device virtconsole,chardev=foo -chardev stdio,id=foo