1000th COMMIT: Kernel: Add basic E1000 driver

This driver is only capable to read mac address and enable and read
link status

kernel/include/kernel/Networking/E1000.h

@@ -0,0 +1,58 @@
+#pragma once
+
+#include <BAN/UniqPtr.h>
+#include <kernel/Networking/NetworkDriver.h>
+#include <kernel/PCI.h>
+
+#define E1000_NUM_RX_DESC 32
+#define E1000_NUM_TX_DESC 8
+
+namespace Kernel
+{
+
+	class E1000 final : public NetworkDriver
+	{
+	public:
+		static BAN::ErrorOr<BAN::UniqPtr<E1000>> create(const PCIDevice&);
+		~E1000();
+
+		virtual uint8_t* get_mac_address() override { return m_mac_address; }
+		virtual BAN::ErrorOr<void> send_packet(const void* data, uint16_t len) override;
+
+		virtual bool link_up() override { return m_link_up; }
+		virtual int link_speed() override;
+
+	private:
+		E1000() = default;
+		BAN::ErrorOr<void> initialize(const PCIDevice&);
+
+		static void interrupt_handler();
+
+		void write32(uint16_t reg, uint32_t value);
+		uint32_t read32(uint16_t reg);
+
+		void detect_eeprom();
+		uint32_t eeprom_read(uint8_t addr);
+		BAN::ErrorOr<void> read_mac_address();
+
+		void initialize_rx();
+		void initialize_tx();
+
+		void enable_link();
+		void enable_interrupts();
+		
+		void handle_receive();
+
+	private:
+		PCIDevice::BarType		m_bar_type {};
+		uint64_t				m_bar_addr {};
+		bool					m_has_eerprom { false };
+		uint8_t					m_mac_address[6] {};
+		uint16_t				m_rx_current {};
+		uint16_t				m_tx_current {};
+		struct e1000_rx_desc*	m_rx_descs[E1000_NUM_RX_DESC] {};
+		struct e1000_tx_desc*	m_tx_descs[E1000_NUM_TX_DESC] {};
+		bool					m_link_up { false };
+	};
+
+}

kernel/include/kernel/Networking/NetworkDriver.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#include <BAN/Errors.h>
+
+namespace Kernel
+{
+
+	class NetworkDriver
+	{
+	public:
+		virtual ~NetworkDriver() {}
+
+		virtual uint8_t* get_mac_address() = 0;
+		virtual BAN::ErrorOr<void> send_packet(const void* data, uint16_t len) = 0;
+
+		virtual bool link_up() = 0;
+		virtual int link_speed() = 0;
+	};
+
+}

kernel/include/kernel/PCI.h

@@ -7,6 +7,14 @@ namespace Kernel
 
 	class PCIDevice
 	{
+	public:
+		enum class BarType
+		{
+			INVAL,
+			MEM,
+			IO,
+		};
+
 	public:
 		PCIDevice(uint8_t, uint8_t, uint8_t);
 
@@ -24,6 +32,9 @@ namespace Kernel
 		uint8_t subclass() const { return m_subclass; }
 		uint8_t prog_if() const { return m_prog_if; }
 
+		BarType read_bar_type(uint8_t) const;
+		uint64_t read_bar_address(uint8_t) const;
+
 		void enable_bus_mastering() const;
 		void disable_bus_mastering() const;
 
@@ -41,6 +52,8 @@ namespace Kernel
 		uint8_t m_class_code;
 		uint8_t m_subclass;
 		uint8_t m_prog_if;
+
+		uint8_t m_header_type;
 	};
 
 	class PCI