--- /dev/null
+#ifndef _X86_64_PAGE_H
+#define _X86_64_PAGE_H
+
+#include <lwk/const.h>
+
+/**
+ * Define the base page size, 4096K on x86_64.
+ * PAGE_SHIFT defines the base page size.
+ */
+#define PAGE_SHIFT 12
+#define PAGE_SIZE (_AC(1,UL) << PAGE_SHIFT)
+#define PAGE_MASK (~(PAGE_SIZE-1))
+#define PHYSICAL_PAGE_MASK (~(PAGE_SIZE-1) & __PHYSICAL_MASK)
+
+/**
+ * The kernel is mapped into the virtual address space of every task:
+ *
+ * [PAGE_OFFSET, TOP_OF_MEMORY) Kernel-space virtual memory region
+ * [0, PAGE_OFFSET] User-space virtual memory region
+ */
+#define PAGE_OFFSET _AC(0xffff810000000000, UL)
+
+/**
+ * The bootloader loads the LWK at address __PHYSICAL_START in physical memory.
+ * This must be aligned on a 2 MB page boundary... or else.
+ */
+#define __PHYSICAL_START CONFIG_PHYSICAL_START
+#define __KERNEL_ALIGN 0x200000
+
+/**
+ * If you hit this error when compiling the LWK, change your config file so that
+ * CONFIG_PHYSICAL_START is aligned to a 2 MB boundary.
+ */
+#if (CONFIG_PHYSICAL_START % __KERNEL_ALIGN) != 0
+#error "CONFIG_PHYSICAL_START must be a multiple of 2MB"
+#endif
+
+/**
+ * The kernel page tables map the kernel image text and data starting at
+ * virtual address __START_KERNEL_map. The kernel text starts at
+ * __START_KERNEL.
+ */
+#define __START_KERNEL_map _AC(0xffffffff80000000, UL)
+#define __START_KERNEL (__START_KERNEL_map + __PHYSICAL_START)
+
+/* See Documentation/x86_64/mm.txt for a description of the memory map. */
+#define __PHYSICAL_MASK_SHIFT 46
+#define __PHYSICAL_MASK ((_AC(1,UL) << __PHYSICAL_MASK_SHIFT) - 1)
+#define __VIRTUAL_MASK_SHIFT 48
+#define __VIRTUAL_MASK ((_AC(1,UL) << __VIRTUAL_MASK_SHIFT) - 1)
+
+#define TASK_ORDER 1
+#define TASK_SIZE (PAGE_SIZE << TASK_ORDER)
+#define CURRENT_MASK (~(TASK_SIZE-1))
+
+#define EXCEPTION_STACK_ORDER 0
+#define EXCEPTION_STKSZ (PAGE_SIZE << EXCEPTION_STACK_ORDER)
+
+#define DEBUG_STACK_ORDER EXCEPTION_STACK_ORDER
+#define DEBUG_STKSZ (PAGE_SIZE << DEBUG_STACK_ORDER)
+
+#define IRQSTACK_ORDER 2
+#define IRQSTACKSIZE (PAGE_SIZE << IRQSTACK_ORDER)
+
+#define STACKFAULT_STACK 1
+#define DOUBLEFAULT_STACK 2
+#define NMI_STACK 3
+#define DEBUG_STACK 4
+#define MCE_STACK 5
+#define N_EXCEPTION_STACKS 5 /* hw limit is 7 */
+
+/**
+ * Macros for converting between physical address and kernel virtual address.
+ * NOTE: These only work for kernel virtual addresses in the identity map.
+ */
+#ifndef __ASSEMBLY__
+extern unsigned long __phys_addr(unsigned long virt_addr);
+#endif
+#define __pa(x) __phys_addr((unsigned long)(x))
+#define __pa_symbol(x) __phys_addr((unsigned long)(x))
+#define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET))
+#define __boot_va(x) __va(x)
+#define __boot_pa(x) __pa(x)
+
+#ifndef __ASSEMBLY__
+/*
+ * These are used to make use of C type-checking..
+ */
+typedef struct { unsigned long pte; } pte_t;
+typedef struct { unsigned long pmd; } pmd_t;
+typedef struct { unsigned long pud; } pud_t;
+typedef struct { unsigned long pgd; } pgd_t;
+#define PTE_MASK PHYSICAL_PAGE_MASK
+
+
+extern pud_t level3_kernel_pgt[512];
+extern pud_t level3_physmem_pgt[512];
+extern pud_t level3_ident_pgt[512];
+extern pmd_t level2_kernel_pgt[512];
+extern pgd_t init_level4_pgt[];
+extern pgd_t boot_level4_pgt[];
+
+typedef struct { unsigned long pgprot; } pgprot_t;
+
+extern unsigned long end_pfn;
+
+#endif
+
+#define PTRS_PER_PGD 512
+#define KERNEL_TEXT_SIZE (40*1024*1024)
+
+#define pte_val(x) ((x).pte)
+#define pmd_val(x) ((x).pmd)
+#define pud_val(x) ((x).pud)
+#define pgd_val(x) ((x).pgd)
+#define pgprot_val(x) ((x).pgprot)
+
+#define __pte(x) ((pte_t) { (x) } )
+#define __pmd(x) ((pmd_t) { (x) } )
+#define __pud(x) ((pud_t) { (x) } )
+#define __pgd(x) ((pgd_t) { (x) } )
+#define __pgprot(x) ((pgprot_t) { (x) } )
+
+#define LARGE_PAGE_MASK (~(LARGE_PAGE_SIZE-1))
+#define LARGE_PAGE_SIZE (_AC(1,UL) << PMD_SHIFT)
+
+#endif
