/mach_kernel

% file /mach_kernel 
/mach_kernel: Mach-O universal binary with 3 architectures
/mach_kernel (for architecture x86_64): Mach-O 64-bit executable x86_64
/mach_kernel (for architecture i386):   Mach-O executable i386
/mach_kernel (for architecture ppc):    Mach-O executable ppc

ppcにインストールできないハズなのになぜカーネルにppcが含まれるのだ？ロゼッタのためか？