Kernel: Rename Console => ConsoleDevice

This change will help to distinguish between the console
device and the Console abstraction layer in the Graphics
subsystem later.

Kernel/ConsoleDevice.cpp

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Singleton.h>
+#include <Kernel/ConsoleDevice.h>
+#include <Kernel/IO.h>
+#include <Kernel/SpinLock.h>
+#include <Kernel/kstdio.h>
+
+// Bytes output to 0xE9 end up on the Bochs console. It's very handy.
+#define CONSOLE_OUT_TO_E9
+
+static AK::Singleton<ConsoleDevice> s_the;
+static Kernel::SpinLock g_console_lock;
+
+UNMAP_AFTER_INIT void ConsoleDevice::initialize()
+{
+    s_the.ensure_instance();
+}
+
+ConsoleDevice& ConsoleDevice::the()
+{
+    return *s_the;
+}
+
+bool ConsoleDevice::is_initialized()
+{
+    return s_the.is_initialized();
+}
+
+UNMAP_AFTER_INIT ConsoleDevice::ConsoleDevice()
+    : CharacterDevice(5, 1)
+{
+}
+
+UNMAP_AFTER_INIT ConsoleDevice::~ConsoleDevice()
+{
+}
+
+bool ConsoleDevice::can_read(const Kernel::FileDescription&, size_t) const
+{
+    return false;
+}
+
+Kernel::KResultOr<size_t> ConsoleDevice::read(FileDescription&, u64, Kernel::UserOrKernelBuffer&, size_t)
+{
+    // FIXME: Implement reading from the console.
+    //        Maybe we could use a ring buffer for this device?
+    return 0;
+}
+
+Kernel::KResultOr<size_t> ConsoleDevice::write(FileDescription&, u64, const Kernel::UserOrKernelBuffer& data, size_t size)
+{
+    if (!size)
+        return 0;
+
+    return data.read_buffered<256>(size, [&](u8 const* bytes, size_t bytes_count) {
+        for (size_t i = 0; i < bytes_count; i++)
+            put_char((char)bytes[i]);
+        return bytes_count;
+    });
+}
+
+void ConsoleDevice::put_char(char ch)
+{
+    Kernel::ScopedSpinLock lock(g_console_lock);
+#ifdef CONSOLE_OUT_TO_E9
+    //if (ch != 27)
+    IO::out8(0xe9, ch);
+#endif
+    m_logbuffer.enqueue(ch);
+}