cloud-hypervisor: Add the architecture crates

Both crates are based on Firecracker commit 9cdb5b2.
They are ported to the new memory model and tests have been fixed
accordingly.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

arch/src/lib.rs

@@ -0,0 +1,54 @@
+// Copyright 2018 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0
+
+#![allow(
+    clippy::unreadable_literal,
+    clippy::const_static_lifetime,
+    clippy::cast_lossless,
+    clippy::transmute_ptr_to_ptr,
+    clippy::cast_ptr_alignment
+)]
+
+extern crate byteorder;
+extern crate kvm_bindings;
+extern crate libc;
+
+extern crate arch_gen;
+extern crate kvm_ioctls;
+extern crate vm_memory;
+
+use std::result;
+use vm_memory::GuestAddress;
+
+#[derive(Debug, PartialEq)]
+pub enum Error {
+    #[cfg(target_arch = "x86_64")]
+    /// X86_64 specific error triggered during system configuration.
+    X86_64Setup(x86_64::Error),
+    /// The zero page extends past the end of guest_mem.
+    ZeroPagePastRamEnd,
+    /// Error writing the zero page of guest memory.
+    ZeroPageSetup,
+}
+pub type Result<T> = result::Result<T, Error>;
+
+// 1MB.  We don't put anything above here except the kernel itself.
+pub const HIMEM_START: GuestAddress = GuestAddress(0x100000);
+
+#[cfg(target_arch = "aarch64")]
+pub mod aarch64;
+
+#[cfg(target_arch = "aarch64")]
+pub use aarch64::{
+    arch_memory_regions, configure_system, get_reserved_mem_addr, layout::CMDLINE_MAX_SIZE,
+    layout::CMDLINE_START,
+};
+
+#[cfg(target_arch = "x86_64")]
+pub mod x86_64;
+
+#[cfg(target_arch = "x86_64")]
+pub use x86_64::{
+    arch_memory_regions, configure_system, get_32bit_gap_start as get_reserved_mem_addr,
+    layout::CMDLINE_MAX_SIZE, layout::CMDLINE_START,
+};