Implement memory allocation

Cargo.lock

@@ -42,6 +42,7 @@ version = "0.1.0"
 dependencies = [
  "bootloader 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "linked_list_allocator 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "polling_serial 0.1.0",
  "vga_buffer 0.1.0",
  "volatile 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -56,6 +57,14 @@ dependencies = [
  "spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "linked_list_allocator"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "nodrop"
 version = "0.1.13"
@@ -114,6 +123,7 @@ dependencies = [
 "checksum bootloader 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)" = "abfbe6cdea6367860818facc8e4a184f003cb83d7d004acaaf57baebf1949da0"
 "checksum cast 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "926013f2860c46252efceabb19f4a6b308197505082c609025aa6706c011d427"
 "checksum lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+"checksum linked_list_allocator 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)" = "47314ec1d29aa869ee7cb5a5be57be9b1055c56567d59c3fb6689926743e0bea"
 "checksum nodrop 0.1.13 (registry+https://github.com/rust-lang/crates.io-index)" = "2f9667ddcc6cc8a43afc9b7917599d7216aa09c463919ea32c59ed6cac8bc945"
 "checksum spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6e63cff320ae2c57904679ba7cb63280a3dc4613885beafb148ee7bf9aa9042d"
 "checksum ux 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "88dfeb711b61ce620c0cb6fd9f8e3e678622f0c971da2a63c4b3e25e88ed012f"

Cargo.toml

@@ -27,6 +27,7 @@ x86_64 = "0.7.5"
 vga_buffer = { path = "vga_buffer" }
 polling_serial = { path = "polling_serial" }
 volatile = "0.2.6"
+linked_list_allocator = "0.6.4"
 
 [dependencies.lazy_static]
 version = "1.0"

src/allocator.rs

@@ -0,0 +1,58 @@
+use alloc::alloc::{GlobalAlloc, Layout};
+use core::ptr::null_mut;
+use polling_serial::serial_println;
+use x86_64::instructions::bochs_breakpoint;
+use x86_64::structures::paging::mapper::MapToError::PageAlreadyMapped;
+use x86_64::{
+    structures::paging::{
+        mapper::MapToError, FrameAllocator, Mapper, Page, PageTableFlags, Size4KiB,
+    },
+    VirtAddr,
+};
+
+pub const HEAP_START: usize = 0x4444_4444_0000;
+pub const HEAP_SIZE: usize = 0x1 << 20; // 1MB Heap
+
+pub struct Dummy;
+
+unsafe impl GlobalAlloc for Dummy {
+    unsafe fn alloc(&self, _layout: Layout) -> *mut u8 {
+        null_mut()
+    }
+
+    unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {
+        panic!("dealloc should never be called");
+    }
+}
+
+pub fn init_heap(
+    mapper: &mut impl Mapper<Size4KiB>,
+    frame_allocator: &mut impl FrameAllocator<Size4KiB>,
+) -> Result<(), MapToError> {
+    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)
+    };
+
+    let mut i = 0;
+    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() };
+        if i == 0 {
+            serial_println!("Mapped {:?} at {:?}", page, frame);
+        }
+        i = i + 1;
+    }
+
+    unsafe {
+        super::ALLOCATOR.lock().init(HEAP_START, HEAP_SIZE);
+    }
+
+    Ok(())
+}

src/lib.rs

@@ -5,24 +5,20 @@
 #![reexport_test_harness_main = "test_main"]
 #![feature(abi_x86_interrupt)]
 #![feature(asm)]
+#![feature(alloc_error_handler)]
+extern crate alloc;
 
-use core::panic::PanicInfo;
-
-#[cfg(test)]
-use vga_buffer::print;
-
-#[cfg(test)]
-use polling_serial::serial_print;
-
-use polling_serial::serial_println;
-
-use vga_buffer::println;
-use x86_64::instructions::bochs_breakpoint;
-
+pub mod allocator;
 pub mod gdt;
 pub mod interrupts;
 pub mod memory;
 
+use core::panic::PanicInfo;
+use linked_list_allocator::LockedHeap;
+use polling_serial::serial_println;
+use vga_buffer::println;
+use x86_64::instructions::bochs_breakpoint;
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 #[repr(u32)]
 pub enum QemuExitCode {
@@ -30,8 +26,15 @@ pub enum QemuExitCode {
     Failed = 0x11,
 }
 
-// Custom panic handler, required for freestanding program
+#[global_allocator]
+static ALLOCATOR: LockedHeap = LockedHeap::empty();
 
+#[alloc_error_handler]
+fn alloc_error_handler(layout: alloc::alloc::Layout) -> ! {
+    panic!("allocation error: {:?}", layout)
+}
+
+// Custom panic handler, required for freestanding program
 pub fn test_panic_handler(info: &PanicInfo) -> ! {
     serial_println!("[failed]\n");
     serial_println!("Error: {}\n", info);
@@ -73,6 +76,12 @@ pub fn hlt_loop() -> ! {
     }
 }
 
+#[cfg(test)]
+use vga_buffer::print;
+
+#[cfg(test)]
+use polling_serial::serial_print;
+
 #[cfg(test)]
 use bootloader::{entry_point, BootInfo};
 

src/main.rs

@@ -6,24 +6,24 @@
 #![feature(custom_test_frameworks)]
 #![test_runner(dendrobates_tinctoreus_azureus::test_runner)]
 #![reexport_test_harness_main = "test_main"]
-
-use polling_serial::serial_println;
+extern crate alloc;
 
 #[cfg(test)]
 use polling_serial::serial_print;
 
-use vga_buffer::println;
-
-use core::panic::PanicInfo;
-use vga_buffer; // required for custom panic handler
-
-use x86_64;
-
+use alloc::boxed::Box;
 use bootloader::{entry_point, BootInfo};
+use core::panic::PanicInfo;
+use dendrobates_tinctoreus_azureus::allocator;
+use polling_serial::serial_println;
+use vga_buffer; // required for custom panic handler
+use vga_buffer::println;
+use x86_64;
 
 #[cfg(not(test))]
 use dendrobates_tinctoreus_azureus::hlt_loop;
 
+use dendrobates_tinctoreus_azureus::memory::create_example_mapping;
 #[cfg(not(test))]
 use vga_buffer::{set_colors, Color, ForegroundColor};
 
@@ -59,6 +59,9 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
 
     let phys_mem_offset = VirtAddr::new(boot_info.physical_memory_offset);
     // new: initialize a mapper
+    let mut frame_allocator =
+        unsafe { memory::BootInfoFrameAllocator::init(&boot_info.memory_map) };
+
     let mut mapper = unsafe { memory::init(phys_mem_offset) };
 
     let addresses = [
@@ -79,16 +82,9 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
         serial_println!("{:?} -> {:?}", virt, phys);
     }
 
-    let mut frame_allocator =
-        unsafe { memory::BootInfoFrameAllocator::init(&boot_info.memory_map) };
+    allocator::init_heap(&mut mapper, &mut frame_allocator).expect("heap initialization failed");
 
-    // map an unused page
-    let page = Page::containing_address(VirtAddr::new(0));
-    memory::create_example_mapping(page, &mut mapper, &mut frame_allocator);
-
-    // write the string `New!` to the screen through the new mapping
-    let page_ptr: *mut u64 = page.start_address().as_mut_ptr();
-    unsafe { page_ptr.offset(400).write_volatile(0x_f021_f077_f065_f04e) };
+    let x = Box::new(41);
 
     serial_println!("Preparing nasty fault...");
     unsafe {