在我的OS X电脑上,内核是一个32位的二进制文件,但它可以运行64位的二进制文件。这是如何实现的?
cristi:~ diciu$ file ./a.out
./a.out: Mach-O 64-bit executable x86_64
cristi:~ diciu$ file /mach_kernel
/mach_kernel: Mach-O universal binary with 2 architectures
/mach_kernel (for architecture i386): Mach-O executable i386
/mach_kernel (for architecture ppc): Mach-O executable ppc
cristi:~ diciu$ ./a.out
cristi:~ diciu$ echo $?
1