Kernel: Make serial devices to their own class

kernel/include/kernel/Serial.h

@@ -1,11 +1,28 @@
 #pragma once
 
-namespace Serial
+#include <BAN/Errors.h>
+
+namespace Kernel
 {
 
-	void initialize();
+	class Serial
-	bool is_initialized();
+	{
+	public:
+		static void initialize();
+		static bool has_devices();
+		static void putchar_any(char);
 
-	void putchar(char);
+		void putchar(char);
+
+	private:
+		static bool port_has_device(uint16_t);
+
+		bool is_transmit_empty() const;
+
+		bool is_valid() const { return m_port != 0; }
+
+	private:
+		uint16_t m_port { 0 };
+	};
 
 }

kernel/kernel/Debug.cpp

@@ -60,8 +60,8 @@ namespace Debug
 
 	void putchar(char ch)
 	{
-		if (Serial::is_initialized())
+		if (Kernel::Serial::has_devices())
-			return Serial::putchar(ch);
+			return Kernel::Serial::putchar_any(ch);
 		if (Kernel::TTY::is_initialized())
 			return Kernel::TTY::putchar_current(ch);
 	}

kernel/kernel/Serial.cpp

@@ -1,49 +1,76 @@
-#include <BAN/Errors.h>
+#include <BAN/Array.h>
 #include <kernel/IO.h>
+#include <kernel/Serial.h>
 
 #define COM1_PORT 0x3f8
 
-namespace Serial
+namespace Kernel
 {
 
-	static bool s_initialized = false;
+	static constexpr uint16_t s_serial_ports[] = { 0x3F8, 0x2F8, 0x3E8, 0x2E8, 0x5F8, 0x4F8, 0x5E8, 0x4E8 };
+	static BAN::Array<Serial, sizeof(s_serial_ports) / sizeof(*s_serial_ports)> s_serial_devices;
+	static bool s_has_devices { false };
 
-	void initialize()
+	void Serial::initialize()
 	{
-		IO::outb(COM1_PORT + 1, 0x00);    // Disable all interrupts
+		int count = 0;
-		IO::outb(COM1_PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
+		for (size_t i = 0; i < s_serial_devices.size(); i++)
-		IO::outb(COM1_PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
+		{
-		IO::outb(COM1_PORT + 1, 0x00);    //                  (hi byte)
+			if (port_has_device(s_serial_ports[i]))
-		IO::outb(COM1_PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+			{
-		IO::outb(COM1_PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+				s_serial_devices[i].m_port = s_serial_ports[i];
-		IO::outb(COM1_PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+				count++;
-		IO::outb(COM1_PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
+			}
-		IO::outb(COM1_PORT + 0, 0xAE);    // Test serial chip (send byte 0xAE and check if serial returns same byte)
+		}
+		s_has_devices = !!count;
+		dprintln("Initialized {} serial devices", count);
+	}
+
+	bool Serial::port_has_device(uint16_t port)
+	{
+		IO::outb(port + 1, 0x00);	// Disable all interrupts
+		IO::outb(port + 3, 0x80);	// Enable DLAB (set baud rate divisor)
+		IO::outb(port + 0, 0x03);	// Set divisor to 3 (lo byte) 38400 baud
+		IO::outb(port + 1, 0x00);	//                  (hi byte)
+		IO::outb(port + 3, 0x03);	// 8 bits, no parity, one stop bit
+		IO::outb(port + 2, 0xC7);	// Enable FIFO, clear them, with 14-byte threshold
+		IO::outb(port + 4, 0x0B);	// IRQs enabled, RTS/DSR set
+		IO::outb(port + 4, 0x1E);	// Set in loopback mode, test the serial chip
+		IO::outb(port + 0, 0xAE);	// Test serial chip (send byte 0xAE and check if serial returns same byte)
 
 		// Check if serial is faulty (i.e: not same byte as sent)
 		if(IO::inb(COM1_PORT + 0) != 0xAE)
-			return;
+			return false;
 
 		// If serial is not faulty set it in normal operation mode
 		// (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
-		IO::outb(COM1_PORT + 4, 0x0F);
+		IO::outb(port + 4, 0x0F);
-		s_initialized = true;
+
+		return true;
 	}
 
-	bool is_initialized()
+	bool Serial::has_devices()
 	{
-		return s_initialized;
+		return s_has_devices;
 	}
 
-	static int is_transmit_empty() {
+	bool Serial::is_transmit_empty() const
-		return IO::inb(COM1_PORT + 5) & 0x20;
+	{
+		return !(IO::inb(m_port + 5) & 0x20);
 	}
  
-	void putchar(char c)
+	void Serial::putchar(char c)
 	{
-		ASSERT(s_initialized);
+		while (is_transmit_empty())
-		while (is_transmit_empty() == 0);
+			continue;
-		IO::outb(COM1_PORT, c);
+		IO::outb(m_port, c);
+	}
+
+	void Serial::putchar_any(char c)
+	{
+		for (auto& device : s_serial_devices)
+			if (device.is_valid())
+				device.putchar(c);
 	}
 
 }