HowTo: Boot Your Mac Into 64-bit Mode
For those of you that are running the new version of MacOS – Snow Leopard, it may come as a surprise that by default, the kernal boots into 32-bit mode. However, you can change the OS to boot the kernal into 64-bit mode by running the following:
1. Run:
ioreg -l -p IODeviceTree | awk -F'"' '/firmware-abi/{print $4}'
and make sure it returns EFI64
2. If the above command returns EFI64 then edit the following file:
sudo vi /Library/Preferences/SystemConfiguration/com.apple.Boot.plist
and replace the contents with:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>Kernel</key>
<string>mach_kernel</string>
<key>Kernel Flags</key>
<string>arch=x86_64</string>
</dict>
</plist>
3. Save and reboot