diff --git a/src/consts.rs b/src/consts.rs
index 9e82028..465b779 100644
--- a/src/consts.rs
+++ b/src/consts.rs
@@ -1 +1,94 @@
-pub const MAX_CPU_NUM: usize = 8;
\ No newline at end of file
+pub const MAX_CPU_NUM: usize = 8;
+
+// Copy from Redox consts.rs:
+
+// Because the memory map is so important to not be aliased, it is defined here, in one place
+// The lower 256 PML4 entries are reserved for userspace
+// Each PML4 entry references up to 512 GB of memory
+// The top (511) PML4 is reserved for recursive mapping
+// The second from the top (510) PML4 is reserved for the kernel
+    /// The size of a single PML4
+    pub const PML4_SIZE: usize = 0x0000_0080_0000_0000;
+    pub const PML4_MASK: usize = 0x0000_ff80_0000_0000;
+
+    /// Offset of recursive paging
+    pub const RECURSIVE_PAGE_OFFSET: usize = (-(PML4_SIZE as isize)) as usize;
+    pub const RECURSIVE_PAGE_PML4: usize = (RECURSIVE_PAGE_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset of kernel
+    pub const KERNEL_OFFSET: usize = RECURSIVE_PAGE_OFFSET - PML4_SIZE;
+    pub const KERNEL_PML4: usize = (KERNEL_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to kernel heap
+    pub const KERNEL_HEAP_OFFSET: usize = KERNEL_OFFSET - PML4_SIZE;
+    pub const KERNEL_HEAP_PML4: usize = (KERNEL_HEAP_OFFSET & PML4_MASK)/PML4_SIZE;
+    /// Size of kernel heap
+    pub const KERNEL_HEAP_SIZE: usize = 1 * 1024 * 1024; // 1 MB
+
+    /// Offset to kernel percpu variables
+    //TODO: Use 64-bit fs offset to enable this pub const KERNEL_PERCPU_OFFSET: usize = KERNEL_HEAP_OFFSET - PML4_SIZE;
+    pub const KERNEL_PERCPU_OFFSET: usize = 0xC000_0000;
+    /// Size of kernel percpu variables
+    pub const KERNEL_PERCPU_SIZE: usize = 64 * 1024; // 64 KB
+
+    /// Offset to user image
+    pub const USER_OFFSET: usize = 0;
+    pub const USER_PML4: usize = (USER_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user TCB
+    pub const USER_TCB_OFFSET: usize = 0xB000_0000;
+
+    /// Offset to user arguments
+    pub const USER_ARG_OFFSET: usize = USER_OFFSET + PML4_SIZE/2;
+
+    /// Offset to user heap
+    pub const USER_HEAP_OFFSET: usize = USER_OFFSET + PML4_SIZE;
+    pub const USER_HEAP_PML4: usize = (USER_HEAP_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user grants
+    pub const USER_GRANT_OFFSET: usize = USER_HEAP_OFFSET + PML4_SIZE;
+    pub const USER_GRANT_PML4: usize = (USER_GRANT_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user stack
+    pub const USER_STACK_OFFSET: usize = USER_GRANT_OFFSET + PML4_SIZE;
+    pub const USER_STACK_PML4: usize = (USER_STACK_OFFSET & PML4_MASK)/PML4_SIZE;
+    /// Size of user stack
+    pub const USER_STACK_SIZE: usize = 1024 * 1024; // 1 MB
+
+    /// Offset to user sigstack
+    pub const USER_SIGSTACK_OFFSET: usize = USER_STACK_OFFSET + PML4_SIZE;
+    pub const USER_SIGSTACK_PML4: usize = (USER_SIGSTACK_OFFSET & PML4_MASK)/PML4_SIZE;
+    /// Size of user sigstack
+    pub const USER_SIGSTACK_SIZE: usize = 256 * 1024; // 256 KB
+
+    /// Offset to user TLS
+    pub const USER_TLS_OFFSET: usize = USER_SIGSTACK_OFFSET + PML4_SIZE;
+    pub const USER_TLS_PML4: usize = (USER_TLS_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary image (used when cloning)
+    pub const USER_TMP_OFFSET: usize = USER_TLS_OFFSET + PML4_SIZE;
+    pub const USER_TMP_PML4: usize = (USER_TMP_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary heap (used when cloning)
+    pub const USER_TMP_HEAP_OFFSET: usize = USER_TMP_OFFSET + PML4_SIZE;
+    pub const USER_TMP_HEAP_PML4: usize = (USER_TMP_HEAP_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary page for grants
+    pub const USER_TMP_GRANT_OFFSET: usize = USER_TMP_HEAP_OFFSET + PML4_SIZE;
+    pub const USER_TMP_GRANT_PML4: usize = (USER_TMP_GRANT_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary stack (used when cloning)
+    pub const USER_TMP_STACK_OFFSET: usize = USER_TMP_GRANT_OFFSET + PML4_SIZE;
+    pub const USER_TMP_STACK_PML4: usize = (USER_TMP_STACK_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary sigstack (used when cloning)
+    pub const USER_TMP_SIGSTACK_OFFSET: usize = USER_TMP_STACK_OFFSET + PML4_SIZE;
+    pub const USER_TMP_SIGSTACK_PML4: usize = (USER_TMP_SIGSTACK_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset to user temporary tls (used when cloning)
+    pub const USER_TMP_TLS_OFFSET: usize = USER_TMP_SIGSTACK_OFFSET + PML4_SIZE;
+    pub const USER_TMP_TLS_PML4: usize = (USER_TMP_TLS_OFFSET & PML4_MASK)/PML4_SIZE;
+
+    /// Offset for usage in other temporary pages
+    pub const USER_TMP_MISC_OFFSET: usize = USER_TMP_TLS_OFFSET + PML4_SIZE;
+    pub const USER_TMP_MISC_PML4: usize = (USER_TMP_MISC_OFFSET & PML4_MASK)/PML4_SIZE;