Kernel: Abstract FramebufferConsole away from contiguous physical range

Currently, Kernel::Graphics::FramebufferConsole is written assuming that
the underlying framebuffer memory exists in physically contiguous
memory. There are a bunch of framebuffer devices that would need to use
the components of FramebufferConsole (in particular access to the kernel
bitmap font rendering logic). To reduce code duplication, framebuffer
console has been split into two parts, the abstract
GenericFramebufferConsole class which does the rendering, and the
ContiguousFramebufferConsole class which contains all logic related to
managing the underling vm object.

Also, a new flush method has been added to the class, to support devices
that require an extra flush step to render.

Kernel/Graphics/Console/ContiguousFramebufferConsole.h

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2021, Sahan Fernando <sahan.h.fernando@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <Kernel/Graphics/Console/GenericFramebufferConsole.h>
+
+namespace Kernel::Graphics {
+
+class ContiguousFramebufferConsole final : public GenericFramebufferConsole {
+public:
+    static NonnullRefPtr<ContiguousFramebufferConsole> initialize(PhysicalAddress, size_t width, size_t height, size_t pitch);
+
+    virtual void set_resolution(size_t width, size_t height, size_t pitch) override;
+    virtual void flush() override { }
+
+private:
+    virtual u8* framebuffer_data() override
+    {
+        return m_framebuffer_region->vaddr().as_ptr();
+    }
+    OwnPtr<Region> m_framebuffer_region;
+    ContiguousFramebufferConsole(PhysicalAddress, size_t width, size_t height, size_t pitch);
+    PhysicalAddress m_framebuffer_address;
+};
+
+}