PAGE_SIZE is already defined in memory/mod.rs

posts/DRAFT-paging.md

@@ -13,7 +13,8 @@ TODO
 Let's create a basic `memory/paging/mod.rs` module:
 
 ```rust
-pub const PAGE_SIZE: usize = 4096;
+use memory::PAGE_SIZE;
+
 const ENTRY_COUNT: usize = 512;
 
 pub type PhysicalAddress = usize;
@@ -23,7 +24,7 @@ pub struct Page {
    number: usize,
 }
 ```
-We define constants for the page size and the number of entries per table. To make future function signatures more expressive, we can use the type aliases `PhysicalAddress` and `VirtualAddress`. The `Page` struct is similar to the `Frame` struct in the [previous post], but represents a virtual page instead of a physical frame.
+We import the `PAGE_SIZE` and define a constant for the number of entries per table. To make future function signatures more expressive, we can use the type aliases `PhysicalAddress` and `VirtualAddress`. The `Page` struct is similar to the `Frame` struct in the [previous post], but represents a virtual page instead of a physical frame.
 
 [previous post]: {{ page.previous.url }}
 

src/memory/paging/mod.rs

@@ -1,5 +1,5 @@
 use core::ptr::Unique;
-use memory::{Frame, FrameAllocator};
+use memory::{PAGE_SIZE, Frame, FrameAllocator};
 use self::table::{Table, Level4};
 use self::entry::*;
 
@@ -30,7 +30,6 @@ pub fn test<A>(frame_allocator: &mut A)
     mapping::map(&Page::containing_address(0x0), PRESENT, frame_allocator);
 }
 
-pub const PAGE_SIZE: usize = 4096;
 const ENTRY_COUNT: usize = 512;
 
 pub type PhysicalAddress = usize;

src/memory/paging/translate.rs

@@ -1,7 +1,7 @@
-use super::{VirtualAddress, PhysicalAddress, Page, PAGE_SIZE, ENTRY_COUNT};
+use super::{VirtualAddress, PhysicalAddress, Page, ENTRY_COUNT};
 use super::table::P4;
 use super::entry::HUGE_PAGE;
-use memory::Frame;
+use memory::{PAGE_SIZE, Frame};
 
 pub fn translate(virtual_address: VirtualAddress) -> Option<PhysicalAddress> {
     let offset = virtual_address % PAGE_SIZE;