Kernel: Move a bunch of generic devices code into new subdirectory

Kernel/Devices/Generic/FullDevice.cpp

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/API/POSIX/errno.h>
+#include <Kernel/Devices/DeviceManagement.h>
+#include <Kernel/Devices/Generic/FullDevice.h>
+#include <Kernel/Sections.h>
+
+namespace Kernel {
+
+UNMAP_AFTER_INIT NonnullLockRefPtr<FullDevice> FullDevice::must_create()
+{
+    auto full_device_or_error = DeviceManagement::try_create_device<FullDevice>();
+    // FIXME: Find a way to propagate errors
+    VERIFY(!full_device_or_error.is_error());
+    return full_device_or_error.release_value();
+}
+
+UNMAP_AFTER_INIT FullDevice::FullDevice()
+    : CharacterDevice(1, 7)
+{
+}
+
+UNMAP_AFTER_INIT FullDevice::~FullDevice() = default;
+
+bool FullDevice::can_read(OpenFileDescription const&, u64) const
+{
+    return true;
+}
+
+ErrorOr<size_t> FullDevice::read(OpenFileDescription&, u64, UserOrKernelBuffer& buffer, size_t size)
+{
+    TRY(buffer.memset(0, size));
+    return size;
+}
+
+ErrorOr<size_t> FullDevice::write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t size)
+{
+    if (size == 0)
+        return 0;
+    return ENOSPC;
+}
+}