Added dummy allocator

Author: keinstn

Cargo.toml

@@ -18,7 +18,7 @@ features = ["spin_no_std"]
 [package.metadata.bootimage]
 build-command = [
     "build",
-    "-Z", "build-std=core,compiler_builtins",
+    "-Z", "build-std=core,compiler_builtins,alloc",
     "-Z", "build-std-features=compiler-builtins-mem",
     "--target", "x86_64-my_os.json"
 ]

Makefile

@@ -5,7 +5,7 @@ ARCH = x86_64
 
 build:
 	cargo build \
-		-Z build-std=core,compiler_builtins \
+		-Z build-std=core,compiler_builtins,alloc \
 		-Z build-std-features=compiler-builtins-mem  \
 		--target ${ARCH}-${PROJECT}.json
 

src/allocator.rs

@@ -0,0 +1,17 @@
+use alloc::alloc::{GlobalAlloc, Layout};
+use core::ptr::null_mut;
+
+#[global_allocator]
+static ALLOCATOR: Dummy = Dummy;
+
+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 be never called")
+    }
+}

src/lib.rs

@@ -1,11 +1,14 @@
 #![no_std]
 #![feature(abi_x86_interrupt)]
 
+pub mod allocator;
 pub mod gdt;
 pub mod interrupts;
 pub mod memory;
 pub mod vga_buffer;
 
+extern crate alloc;
+
 pub fn init() {
     gdt::init();
     interrupts::init_idt();

src/main.rs

@@ -5,6 +5,10 @@ use bootloader::{entry_point, BootInfo};
 use core::panic::PanicInfo;
 use my_os::println;
 
+extern crate alloc;
+
+use alloc::boxed::Box;
+
 entry_point!(kernel_main);
 
 fn kernel_main(boot_info: &'static BootInfo) -> ! {
@@ -19,11 +23,7 @@ fn kernel_main(boot_info: &'static BootInfo) -> ! {
     let mut mapper = unsafe { memory::init(phys_mem_offset) };
     let mut frame_allocator = unsafe { BootInfoFrameAllocator::init(&boot_info.memory_map) };
 
-    let page = Page::containing_address(VirtAddr::new(0));
-    memory::create_example_mapping(page, &mut mapper, &mut frame_allocator);
-
-    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);
 
     println!("It did not crash!");
     my_os::hlt_loop();