wiiMac Bootloader

When running Mac OS X on the Nintendo Wii via wiiMac, the following hardware components are currently not supported:

• Wi-Fi
• Bluetooth
• Optical drive
• Hardware-accelerated graphics
• Audio

The BootMii SD card is used to load the wiiMac bootloader.

1. Download the latest release from the wiiMac Releases page.
2. Copy the entire wiiMac folder (which includes wiiMac.elf and config.txt) to the root of your SD card.
3. Verify the file structure is as follows:

/
├── bootmii
│   ├── ppcboot.elf
│   └── armboot.bin
└── wiiMac
    ├── wiiMac.elf
    └── config.txt

4. Edit /wiiMac/config.txt to set the correct video_mode for your Wii region: ntscp, ntsci, pal60, or pal50.

/
└── bootmii
    ├── ppcboot.elf
    └── armboot.bin
└── wiiMac
    ├── wiiMac.elf
    └── config.txt

To use wiiMac, ensure you meet the following requirements:

• Hardware: A Wii with an SD card slot (Note: Wii Mini is not supported).
• Software: A soft-modded Wii with BootMii installed as boot2 or IOS.
• BootMii SD Card: An MBR-formatted SD card with a FAT32 partition containing the following files:
  • /bootmii/ppcboot.elf
  • /bootmii/armboot.bin
• Mac OS X System SD Card: A second SD card (at least 4 GB) to hold the Mac OS X system, installer, and support files.

On a Linux host, use parted and mkfs tools. Warning: This will erase the SD card.

1. Identify the device:

   lsblk -f

2. Partition the card using the mac label:

   # Replace sdX with the correct device for the SD card
   sudo parted /dev/sdX --script \
     mklabel mac \
     mkpart primary hfs+ 1MiB -1088MiB \
     mkpart primary hfs+ -1088MiB -64MiB \
     mkpart primary fat32 -64MiB 100%

3. Install required HFS+ tools if not present:
   • Debian/Ubuntu: sudo apt install hfsprogs
   • Arch: sudo pacman -S hfsprogs
   • Fedora: sudo dnf install hfsplus-tools
4. Format the partitions:

   # Replace sdX with the correct device for the SD card
   sudo mkfs.hfsplus -v "Macintosh HD" /dev/sdX2
   sudo mkfs.hfsplus -v "Install" /dev/sdX3
   sudo mkfs.vfat -F 32 -n "Support" /dev/sdX4

After the initial setup, perform these steps to improve performance and visual quality:

1. Resolution: Open System Preferences > Display and reduce the resolution to 640x480.
2. Dock: Open System Preferences > Dock and reduce the size or enable Dock hiding to save screen real estate.
3. Swap File: Reduce the swap file size to improve responsiveness. Edit /etc/rc and change the dynamic_pager line:
   • From: dynamic_pager -H 40000000 -L 160000000 -S 80000000 -F ${swapdir}/swapfile
   • To: dynamic_pager -H 40000000 -L 160000000 -S 8000000 -F ${swapdir}/swapfile
   • Reboot for changes to take effect.

The FAT32 Support partition requires a patched kernel and drivers to function on the Wii.

1. Create a folder named wiiMac at the root of the Support partition.
2. Copy the appropriate mach_kernel and driver .kext files into that folder.
3. Verify the structure:

/
└── wiiMac
    ├── mach_kernel
    ├── IOUSBFamily.kext
    └── NintendoWii*.kext (all other drivers)

Note for WSL Users: Since the WSL2 kernel often lacks vfat support, use mtools to copy files:

sudo mmd -i /dev/sdXA ::/wiiMac
sudo mcopy -s -i /dev/sdXA /mnt/c/path/to/files/* ::/wiiMac

On a macOS host, use diskutil to partition the target SD card. Warning: This will erase the SD card.

1. Identify the device identifier:

   diskutil list

2. Partition the card using the APM scheme with three partitions: Macintosh HD (HFS+), Install (1GB HFS+), and Support (64MB FAT32).

   # Replace diskX with the correct device for the SD card
   diskutil partitionDisk diskX APM \
     HFS+ "Macintosh HD" R \
     HFS+ "Install" 1G\
     FAT32 "Support" 64M

While running in the wiiMac bootloader, you can use the following hardware inputs (GPIO) to change boot behavior:

• Power Button (GPIO_POWER): Cycles through available bootable partitions. If no partition is selected, it increments the selected_boot_partition_index to the next bootable partition found on the SD card.
• Reset Button (GPIO_RESET): Triggers an immediate attempt to load the kernel from the currently selected partition.
• Eject Button (GPIO_EJECT): Cycles through the predefined sets of boot arguments (overriding the default command line). There are up to 5 different boot argument sets available.