Kernel: Start work on making tty a file

TTY is now a file that you can read from/write to. I still have
to port shell to use this new interface

kernel/include/kernel/Terminal/TTY.h

@@ -0,0 +1,113 @@
+#pragma once
+
+#include <BAN/Array.h>
+#include <kernel/Device.h>
+#include <kernel/Input/KeyEvent.h>
+#include <kernel/SpinLock.h>
+#include <kernel/Terminal/TerminalDriver.h>
+#include <kernel/Terminal/termios.h>
+#include <kernel/Semaphore.h>
+
+
+namespace Kernel
+{
+	
+	class TTY : public CharacterDevice
+	{
+	public:
+		TTY(TerminalDriver*);
+		void clear();
+		void putchar(uint8_t ch);
+		void set_cursor_position(uint32_t x, uint32_t y);
+		void set_font(const Kernel::Font&);
+
+		uint32_t height() const { return m_height; }
+		uint32_t width() const { return m_width; }
+
+		// for kprint
+		static void putchar_current(uint8_t ch);
+		static bool is_initialized();
+
+		virtual BAN::ErrorOr<size_t> read(size_t, void*, size_t) override;
+		virtual BAN::ErrorOr<size_t> write(size_t, const void*, size_t) override;
+
+	private:
+		void reset_ansi();
+		void handle_ansi_csi(uint8_t ch);
+		void handle_ansi_csi_color();
+		void putchar_at(uint32_t codepoint, uint32_t x, uint32_t y);
+		void render_from_buffer(uint32_t x, uint32_t y);
+
+		void on_key(Input::KeyEvent);
+
+	private:
+		enum class State
+		{
+			Normal,
+			WaitingAnsiEscape,
+			WaitingAnsiCSI,
+			WaitingUTF8,
+		};
+
+		struct AnsiState
+		{
+			int32_t nums[2]	{ -1, -1 };
+			int32_t index { 0 };
+		};
+
+		struct UTF8State
+		{
+			uint32_t codepoint { 0 };
+			uint8_t bytes_missing { 0 };
+		};
+
+		struct Cell
+		{
+			TerminalDriver::Color foreground { TerminalColor::BRIGHT_WHITE };
+			TerminalDriver::Color background { TerminalColor::BLACK };
+			uint32_t codepoint { ' ' };
+		};
+
+	private:
+		Kernel::SpinLock m_lock;
+
+		State m_state { State::Normal };
+		AnsiState m_ansi_state { };
+		UTF8State m_utf8_state { };
+
+		uint32_t m_width { 0 };
+		uint32_t m_height { 0 };
+
+		uint32_t m_row { 0 };
+		uint32_t m_column { 0 };
+		Cell* m_buffer { nullptr };
+
+		TerminalDriver::Color m_foreground { TerminalColor::BRIGHT_WHITE };
+		TerminalDriver::Color m_background { TerminalColor::BLACK };
+
+		termios m_termios;
+
+		struct Buffer
+		{
+			BAN::Array<uint8_t, 1024> buffer;
+			size_t bytes { 0 };
+			bool flush { false };
+			Semaphore semaphore;
+		};
+		Buffer m_output;
+
+		TerminalDriver* m_terminal_driver { nullptr };
+
+	public:
+		virtual Mode mode() const override { return { Mode::IFCHR | Mode::IRUSR }; }
+		virtual uid_t uid() const override { return 0; }
+		virtual gid_t gid() const override { return 0; }
+		virtual dev_t rdev() const override { return m_rdev; }
+		virtual BAN::StringView name() const { return m_name; }
+
+	private:
+		const dev_t m_rdev;
+		const BAN::String m_name;
+	};
+
+}

kernel/include/kernel/Terminal/TerminalDriver.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <kernel/Font.h>
+
+#include <stdint.h>
+
+class TerminalDriver
+{
+public:
+	struct Color
+	{
+		constexpr Color(uint32_t rgb)
+			: rgb(rgb)
+		{ }
+		constexpr Color(uint8_t r, uint8_t g, uint8_t b)
+			: rgb(((uint32_t)r << 16) | ((uint32_t)g << 8) | b)
+		{ }
+		uint8_t red()	const { return (rgb >> 0x10) & 0xFF; }
+		uint8_t green() const { return (rgb >> 0x08) & 0xFF; }
+		uint8_t blue()	const { return (rgb >> 0x00) & 0xFF; }
+		uint32_t rgb;
+	};
+
+public:
+	TerminalDriver() : m_font(MUST(Kernel::Font::prefs())) {}
+	virtual ~TerminalDriver() {}
+	virtual uint32_t width() const = 0;
+	virtual uint32_t height() const = 0;
+
+	virtual void putchar_at(uint16_t, uint32_t, uint32_t, Color, Color) = 0;
+	virtual void clear(Color) = 0;
+
+	virtual void set_cursor_position(uint32_t, uint32_t) = 0;
+
+	void set_font(const Kernel::Font& font) { m_font = font; };
+	const Kernel::Font& font() const { return m_font; }
+
+private:
+	Kernel::Font m_font;
+};
+
+namespace TerminalColor
+{
+	static constexpr TerminalDriver::Color BLACK			= 0x000000;
+	static constexpr TerminalDriver::Color BLUE				= 0x0000AA;
+	static constexpr TerminalDriver::Color GREEN			= 0x00AA00;
+	static constexpr TerminalDriver::Color CYAN				= 0x00AAAA;
+	static constexpr TerminalDriver::Color RED				= 0xAA0000;
+	static constexpr TerminalDriver::Color MAGENTA			= 0xAA00AA;
+	static constexpr TerminalDriver::Color YELLOW			= 0xAA5500;
+	static constexpr TerminalDriver::Color WHITE			= 0xAAAAAA;
+
+	static constexpr TerminalDriver::Color BRIGHT_BLACK		= 0x555555;
+	static constexpr TerminalDriver::Color BRIGHT_BLUE		= 0x5555FF;
+	static constexpr TerminalDriver::Color BRIGHT_GREEN		= 0x55FF55;
+	static constexpr TerminalDriver::Color BRIGHT_CYAN		= 0x55FFFF;
+	static constexpr TerminalDriver::Color BRIGHT_RED		= 0xFF5555;
+	static constexpr TerminalDriver::Color BRIGHT_MAGENTA	= 0xFF55FF;
+	static constexpr TerminalDriver::Color BRIGHT_YELLOW	= 0xFFFF55;
+	static constexpr TerminalDriver::Color BRIGHT_WHITE		= 0xFFFFFF;
+}

kernel/include/kernel/Terminal/VesaTerminalDriver.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include <kernel/Terminal/TerminalDriver.h>
+
+class VesaTerminalDriver final : public TerminalDriver
+{
+public:
+	static VesaTerminalDriver* create();
+	~VesaTerminalDriver();
+
+	virtual uint32_t width() const override { return m_width / font().width(); }
+	virtual uint32_t height() const override { return m_height / font().height(); }
+
+	virtual void putchar_at(uint16_t, uint32_t, uint32_t, Color, Color) override;
+	virtual void clear(Color) override;
+
+	virtual void set_cursor_position(uint32_t, uint32_t) override;
+
+private:
+	VesaTerminalDriver(uint32_t width, uint32_t height, uint32_t pitch, uint8_t bpp, uintptr_t address)
+		: m_width(width)
+		, m_height(height)
+		, m_pitch(pitch)
+		, m_bpp(bpp)
+		, m_address(address)
+	{ }
+
+	void set_pixel(uint32_t, Color);
+
+private:
+	uint32_t m_width = 0;
+	uint32_t m_height = 0;
+	uint32_t m_pitch = 0;
+	uint8_t m_bpp = 0;
+	uintptr_t m_address = 0;
+
+	static constexpr Color s_cursor_color = TerminalColor::BRIGHT_WHITE;
+};

kernel/include/kernel/Terminal/termios.h

@@ -0,0 +1,12 @@
+#pragma once
+
+namespace Kernel
+{
+
+	struct termios
+	{
+		bool canonical { true };
+		bool echo { true };
+	};
+	
+}