WIP: allocator

nel_os_kernel/Cargo.lock

@@ -35,6 +35,15 @@ dependencies = [
  "spin 0.9.8",
 ]
 
+[[package]]
+name = "linked_list_allocator"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "549ce1740e46b291953c4340adcd74c59bcf4308f4cac050fd33ba91b7168f4a"
+dependencies = [
+ "spinning_top",
+]
+
 [[package]]
 name = "lock_api"
 version = "0.4.13"
@@ -54,6 +63,7 @@ name = "nel_os_kernel"
 version = "0.1.0"
 dependencies = [
  "lazy_static",
+ "linked_list_allocator",
  "nel_os_common",
  "spin 0.10.0",
  "uart_16550",
@@ -96,6 +106,15 @@ dependencies = [
  "lock_api",
 ]
 
+[[package]]
+name = "spinning_top"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b9eb1a2f4c41445a3a0ff9abc5221c5fcd28e1f13cd7c0397706f9ac938ddb0"
+dependencies = [
+ "lock_api",
+]
+
 [[package]]
 name = "uart_16550"
 version = "0.3.2"

nel_os_kernel/Cargo.toml

@@ -9,3 +9,4 @@ spin = "0.10.0"
 uart_16550 = "0.3.2"
 x86_64 = "0.15.2"
 nel_os_common = { path = "../nel_os_common" }
+linked_list_allocator = "0.9.1"

nel_os_kernel/src/allocator.rs

@@ -0,0 +1,47 @@
+use linked_list_allocator::LockedHeap;
+use x86_64::{
+    structures::paging::{
+        mapper::MapToError, FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB,
+    },
+    VirtAddr,
+};
+
+use crate::{
+    constant::{HEAP_SIZE, HEAP_START},
+    info,
+};
+
+#[global_allocator]
+static ALLOCATOR: LockedHeap = LockedHeap::empty();
+
+pub fn init_heap(
+    mapper: &mut impl Mapper<Size4KiB>,
+    frame_allocator: &mut impl FrameAllocator<Size4KiB>,
+) -> Result<(), MapToError<Size4KiB>> {
+    info!(
+        "Initializing heap: 0x{:x} - 0x{:x}",
+        HEAP_START,
+        HEAP_START + HEAP_SIZE - 1
+    );
+    let page_range = {
+        let heap_start = VirtAddr::new(HEAP_START as u64);
+        let heap_end = heap_start + HEAP_SIZE as u64 - 1u64;
+        let heap_start_page = Page::containing_address(heap_start);
+        let heap_end_page = Page::containing_address(heap_end);
+        Page::range_inclusive(heap_start_page, heap_end_page)
+    };
+
+    for page in page_range {
+        let frame = frame_allocator
+            .allocate_frame()
+            .ok_or(MapToError::FrameAllocationFailed)?;
+        let flags = PageTableFlags::PRESENT | PageTableFlags::WRITABLE;
+        unsafe { mapper.map_to(page, frame, flags, frame_allocator)?.flush() };
+    }
+
+    unsafe {
+        ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
+    }
+
+    Ok(())
+}

nel_os_kernel/src/constant.rs

@@ -9,6 +9,8 @@ pub const PKG_VERSION: &str = env!("CARGO_PKG_VERSION");
 pub const PKG_NAME: &str = env!("CARGO_PKG_NAME");
 
 pub const KERNEL_STACK_SIZE: usize = 1024 * 1024;
+pub const HEAP_START: usize = 0x4444_4444_0000;
+pub const HEAP_SIZE: usize = 128 * 1024;
 
 pub const PAGE_SIZE: usize = 4096;
 pub const MAX_MEMORY: usize = 16 * 1024 * 1024 * 1024;

nel_os_kernel/src/main.rs

@@ -1,6 +1,7 @@
 #![no_std]
 #![no_main]
 
+pub mod allocator;
 pub mod constant;
 pub mod logging;
 pub mod memory;
@@ -11,11 +12,12 @@ use core::arch::asm;
 use core::panic::PanicInfo;
 use core::ptr::addr_of;
 
-use x86_64::VirtAddr;
+use x86_64::{structures::paging::OffsetPageTable, VirtAddr};
 
 use crate::{
     constant::{BANNER, KERNEL_STACK_SIZE, PKG_VERSION},
     memory::BitmapMemoryTable,
+    paging::get_active_level_4_table,
 };
 
 #[repr(C, align(16))]
@@ -80,7 +82,7 @@ pub extern "sysv64" fn main(usable_memory: &nel_os_common::memory::UsableMemory)
     }
     info!("Usable memory: {}MiB", count / 1024 / 1024);
 
-    let bitmap_table = BitmapMemoryTable::init(usable_memory);
+    let mut bitmap_table = BitmapMemoryTable::init(usable_memory);
     info!(
         "Memory bitmap initialized: {} -> {}",
         bitmap_table.start, bitmap_table.end
@@ -95,5 +97,10 @@ pub extern "sysv64" fn main(usable_memory: &nel_os_common::memory::UsableMemory)
 
     info!("Usable memory in bitmap: {}MiB", usable_frame * 4 / 1024);
 
+    let level_4_table = get_active_level_4_table();
+    let mut mapper = unsafe { OffsetPageTable::new(level_4_table, VirtAddr::new(0x0)) };
+
+    allocator::init_heap(&mut mapper, &mut bitmap_table).unwrap();
+
     hlt_loop();
 }