// 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;

pub const KERNEL_SIZE: usize = 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 = 8 * 1024 * 1024; // 8 MB

pub const MEMORY_OFFSET: usize = 0;

/// 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 USER32_STACK_OFFSET: usize = 0xB000_0000;
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;
