From 3b4f85576353d126e813af89493dbb6803e14f7a Mon Sep 17 00:00:00 2001
From: WangRunji <wangrunji0408@163.com>
Date: Fri, 13 Apr 2018 14:22:50 +0800
Subject: [PATCH] Modify remap_kernel()

---
 src/memory/mod.rs        | 13 +++++++++----
 src/memory/paging/mod.rs | 15 ++++++++++++---
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/memory/mod.rs b/src/memory/mod.rs
index 83df09e..4e74ce0 100644
--- a/src/memory/mod.rs
+++ b/src/memory/mod.rs
@@ -3,6 +3,7 @@ pub use self::paging::remap_the_kernel;
 pub use self::stack_allocator::Stack;
 use self::paging::PhysicalAddress;
 use multiboot2::BootInformation;
+use consts::KERNEL_OFFSET;
 
 mod area_frame_allocator;
 pub mod heap_allocator;
@@ -20,10 +21,10 @@ pub fn init(boot_info: &BootInformation) -> MemoryController {
         "Elf sections tag required");
 
     let kernel_start = elf_sections_tag.sections()
-        .filter(|s| s.is_allocated()).map(|s| s.addr).min().unwrap();
+        .filter(|s| s.is_allocated()).map(|s| s.start_address()).min().unwrap() as usize;
     let kernel_end = elf_sections_tag.sections()
-        .filter(|s| s.is_allocated()).map(|s| s.addr + s.size).max()
-        .unwrap();
+        .filter(|s| s.is_allocated()).map(|s| s.end_address()).max().unwrap() as usize
+        - KERNEL_OFFSET;
 
     println!("kernel start: {:#x}, kernel end: {:#x}",
              kernel_start,
@@ -31,9 +32,13 @@ pub fn init(boot_info: &BootInformation) -> MemoryController {
     println!("multiboot start: {:#x}, multiboot end: {:#x}",
              boot_info.start_address(),
              boot_info.end_address());
+    println!("memory area:");
+    for area in memory_map_tag.memory_areas() {
+        println!("  addr: {:#x}, size: {:#x}", area.base_addr, area.length);
+    }
 
     let mut frame_allocator = AreaFrameAllocator::new(
-        kernel_start as usize, kernel_end as usize,
+        kernel_start, kernel_end,
         boot_info.start_address(), boot_info.end_address(),
         memory_map_tag.memory_areas());
 
diff --git a/src/memory/paging/mod.rs b/src/memory/paging/mod.rs
index 2135a36..7a7d9b8 100644
--- a/src/memory/paging/mod.rs
+++ b/src/memory/paging/mod.rs
@@ -6,6 +6,7 @@ use memory::{PAGE_SIZE, Frame, FrameAllocator};
 use multiboot2::BootInformation;
 use self::table::{Table, Level4};
 use self::temporary_page::TemporaryPage;
+use consts::KERNEL_OFFSET;
 
 mod entry;
 mod table;
@@ -212,10 +213,18 @@ pub fn remap_the_kernel<A>(allocator: &mut A, boot_info: &BootInformation)
 
             let flags = EntryFlags::from_elf_section_flags(section);
 
-            let start_frame = Frame::containing_address(section.start_address());
-            let end_frame = Frame::containing_address(section.end_address() - 1);
+            fn to_physical_frame(addr: usize) -> Frame {
+                Frame::containing_address(
+                    if addr < KERNEL_OFFSET { addr } 
+                    else { addr - KERNEL_OFFSET })
+            }
+
+            let start_frame = to_physical_frame(section.start_address());
+            let end_frame = to_physical_frame(section.end_address() - 1);
+
             for frame in Frame::range_inclusive(start_frame, end_frame) {
-                mapper.identity_map(frame, flags, allocator);
+                let page = Page::containing_address(frame.start_address() + KERNEL_OFFSET);
+                mapper.map_to(page, frame, flags, allocator);
             }
         }