Porting Linux to x86-64

x86-64 is a 64-bit extension for the IA32 architecture, which is supported by the next generation of AMD CPUs. New features include 64-bit pointers, a 48-bit address space, 16 general purpose 64-bit integer registers, 16 SSE (Streaming SIMD Extensions) registers, and a compatibility mode to support old binaries. The Linux kernel port to x86-64 is based on the existing IA32 port with some extensions, including a new syscall mechanism, 64-bit support and use of interrupt stacks. It also adds a translation layer to allow execution of the system calls of old IA32 binaries. This paper gives a short overview of the x86-64 architecture and the new x86-64 ABI and then discusses internals of the kernel port.