From fda1ab2327bdc7231ca54a2118d0d49380a5ff65 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Mon, 15 Aug 2016 16:29:54 -0600
Subject: [PATCH] Global allocator, page table - protected by spinlock

---
 arch/x86_64/Cargo.toml        |  1 +
 arch/x86_64/src/lib.rs        |  7 +++-
 arch/x86_64/src/memory/mod.rs |  2 +-
 arch/x86_64/src/start.rs      | 68 +++++++++++++++++++----------------
 4 files changed, 46 insertions(+), 32 deletions(-)

diff --git a/arch/x86_64/Cargo.toml b/arch/x86_64/Cargo.toml
index 250c559..a845fa7 100644
--- a/arch/x86_64/Cargo.toml
+++ b/arch/x86_64/Cargo.toml
@@ -5,6 +5,7 @@ version = "0.1.0"
 [dependencies]
 bitflags = "*"
 hole_list_allocator = { path = "../../alloc/hole_list_allocator"}
+spin = "*"
 
 [dependencies.x86]
 default-features = false
diff --git a/arch/x86_64/src/lib.rs b/arch/x86_64/src/lib.rs
index f4102db..eabc8a8 100644
--- a/arch/x86_64/src/lib.rs
+++ b/arch/x86_64/src/lib.rs
@@ -10,11 +10,13 @@
 #![no_std]
 
 extern crate hole_list_allocator as allocator;
-
 #[macro_use]
 extern crate bitflags;
+extern crate spin;
 extern crate x86;
 
+use spin::Mutex;
+
 /// Print to console
 #[macro_export]
 macro_rules! print {
@@ -106,3 +108,6 @@ pub mod start;
 
 /// Task state segment
 pub mod tss;
+
+pub static ALLOCATOR: Mutex<Option<memory::AreaFrameAllocator>> = Mutex::new(None);
+pub static PAGE_TABLE: Mutex<Option<paging::ActivePageTable>> = Mutex::new(None);
diff --git a/arch/x86_64/src/memory/mod.rs b/arch/x86_64/src/memory/mod.rs
index ee79995..59f3730 100644
--- a/arch/x86_64/src/memory/mod.rs
+++ b/arch/x86_64/src/memory/mod.rs
@@ -3,7 +3,7 @@
 
 pub use paging::{PAGE_SIZE, PhysicalAddress};
 
-use self::area_frame_alloc::AreaFrameAllocator;
+pub use self::area_frame_alloc::AreaFrameAllocator;
 
 pub mod area_frame_alloc;
 
diff --git a/arch/x86_64/src/start.rs b/arch/x86_64/src/start.rs
index 99147b9..c70d2bd 100644
--- a/arch/x86_64/src/start.rs
+++ b/arch/x86_64/src/start.rs
@@ -22,45 +22,53 @@ extern {
 
 #[no_mangle]
 pub unsafe extern fn kstart() -> ! {
-    extern {
-        /// The starting byte of the _.bss_ (uninitialized data) segment.
-        static mut __bss_start: u8;
-        /// The ending byte of the _.bss_ (uninitialized data) segment.
-        static mut __bss_end: u8;
-    }
-
-    // Zero BSS, this initializes statics that are set to 0
     {
-        let start_ptr = &mut __bss_start as *mut u8;
-        let end_ptr = & __bss_end as *const u8 as usize;
-
-        if start_ptr as usize <= end_ptr {
-            let size = end_ptr - start_ptr as usize;
-            memset(start_ptr, 0, size);
+        extern {
+            /// The starting byte of the _.bss_ (uninitialized data) segment.
+            static mut __bss_start: u8;
+            /// The ending byte of the _.bss_ (uninitialized data) segment.
+            static mut __bss_end: u8;
         }
 
-        debug_assert_eq!(BSS_TEST_ZERO, 0);
-        debug_assert_eq!(BSS_TEST_NONZERO, 0xFFFFFFFFFFFFFFFF);
-    }
+        // Zero BSS, this initializes statics that are set to 0
+        {
+            let start_ptr = &mut __bss_start as *mut u8;
+            let end_ptr = & __bss_end as *const u8 as usize;
 
-    // Set up GDT
-    gdt::init();
+            if start_ptr as usize <= end_ptr {
+                let size = end_ptr - start_ptr as usize;
+                memset(start_ptr, 0, size);
+            }
 
-    // Set up IDT
-    idt::init(blank);
+            debug_assert_eq!(BSS_TEST_ZERO, 0);
+            debug_assert_eq!(BSS_TEST_NONZERO, 0xFFFFFFFFFFFFFFFF);
+        }
 
-    // Initialize memory management
-    let mut allocator = memory::init(0, &__bss_end as *const u8 as usize);
+        // Set up GDT
+        gdt::init();
 
-    // Initialize paging
-    let mut active_table = paging::init(&mut allocator);
+        // Set up IDT
+        idt::init(blank);
 
-    // Initialize heap
-    let heap_start_page = Page::containing_address(VirtualAddress::new(HEAP_START));
-    let heap_end_page = Page::containing_address(VirtualAddress::new(HEAP_START + HEAP_SIZE-1));
+        // Initialize memory management
+        let mut allocator = memory::init(0, &__bss_end as *const u8 as usize);
 
-    for page in Page::range_inclusive(heap_start_page, heap_end_page) {
-        active_table.map(page, paging::entry::WRITABLE, &mut allocator);
+        // Initialize paging
+        let mut active_table = paging::init(&mut allocator);
+
+        // Initialize heap
+        let heap_start_page = Page::containing_address(VirtualAddress::new(HEAP_START));
+        let heap_end_page = Page::containing_address(VirtualAddress::new(HEAP_START + HEAP_SIZE-1));
+
+        for page in Page::range_inclusive(heap_start_page, heap_end_page) {
+            active_table.map(page, paging::entry::WRITABLE, &mut allocator);
+        }
+
+        // Set global allocator
+        *::ALLOCATOR.lock() = Some(allocator);
+
+        // Set global page table
+        *::PAGE_TABLE.lock() = Some(active_table);
     }
 
     asm!("xchg bx, bx" : : : : "intel", "volatile");