refactor(x86_64/newlib): manually allocate pages for heap

Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>

src/mm/mod.rs

@@ -120,7 +120,17 @@ pub(crate) fn init() {
 		let kernel_heap_size = 10 * LargePageSize::SIZE as usize;
 
 		unsafe {
-			let start = allocate(kernel_heap_size, true);
+			let start = {
+				let physical_address = arch::mm::physicalmem::allocate(size).unwrap();
+				let virtual_address = arch::mm::virtualmem::allocate(size).unwrap();
+
+				let count = size / BasePageSize::SIZE as usize;
+				let mut flags = PageTableEntryFlags::empty();
+				flags.normal().writable().execute_disable();
+				arch::mm::paging::map::<BasePageSize>(virtual_address, physical_address, count, flags);
+
+				virtual_address
+			};
 			ALLOCATOR.init(start.as_mut_ptr(), kernel_heap_size);
 
 			info!("Kernel heap starts at {:#x}", start);