Created a proper driver for the serial bus

* The driver can write to any of the pre-defined serial COM ports
* The driver can read from any of the pre-defined serial COM ports (Untested)

kernel/Makefile

@@ -34,7 +34,8 @@ OFILES = $(OBJ_DIR)/boot.o	\
 		 $(OBJ_DIR)/ataDevice.o \
 		 $(OBJ_DIR)/rsdp.o \
 		 $(OBJ_DIR)/acpi.o \
-		 $(OBJ_DIR)/fat.o
+		 $(OBJ_DIR)/fat.o \
+		 $(OBJ_DIR)/serial.o
 
 OBJ_LINK_LIST = $(CRTI_OBJ) $(CRTBEGIN_OBJ) $(OFILES) $(CRTEND_OBJ) $(CRTN_OBJ)  
 INTERNAL_OBJS = $(CRTI_OBJ) $(OFILES) $(CRTN_OBJ)
@@ -121,6 +122,11 @@ $(OBJ_DIR)/processor.o:
 $(OBJ_DIR)/fat.o:
 	$(CPP) -c storage/filesystems/FAT/FAT.cpp -o $(OBJ_DIR)/fat.o $(CFLAGS) -fno-exceptions -fno-rtti
 
+$(OBJ_DIR)/serial.o:
+	$(CPP) -c drivers/serial/serial.cpp -o $(OBJ_DIR)/serial.o $(CFLAGS) -fno-exceptions -fno-rtti
+
+
+
 # Assembly -> Object files
 $(OBJ_DIR)/boot.o:
 	$(AS) boot/boot.s -o $(OBJ_DIR)/boot.o

kernel/drivers/serial/serial.cpp

@@ -1,19 +1,52 @@
 #include "serial.h"
+#include "../../io/io.h"
 
-Serial Serial::init() {
+// Initializes communication according to the spec given
-    // No clue what to setup yet!
+Serial::Serial(SerialConfig config) {
+    port = config.port;
+    // Disable interrupts
+    outb(config.port + 1, 0x00);
 
-    return Serial();
+    // Enable DLAB
+    outb(config.port + 3, 0x80);
+
+    // set the baudrate
+    outb(config.port + 0, 0x03);
+    outb(config.port + 1, 0x00);
+
+    // configure for 8bits, no parity, one stop bit
+    outb(config.port + 3, 0x03);
+
+    // Enable FIFO, clear them, with 14-byte threshhold
+    outb(config.port + 2, 0xC7);
+    // Enable IRQ's, RTS/DSR set
+    outb(config.port + 4, 0x0B );
+    // Set in loopback mode, test the serial chip.
+    outb(config.port + 4, 0x1E);
+
+    // TEST
+    outb(config.port + 0 , 0xAE);
+
+    if(inb(config.port + 0) != 0xAE)
+        return ; // FAIL
+
+    outb(config.port + 4, 0x0F);
+    return ;
 }
 
-void Serial::print(){
+void Serial::write(void* data, int len) {
-    // Do nothing!
+    while (is_transmit_empty() == 0); // Wait for transmit queue to be free
+    for (int i = 0; i < len ; i++){
+        outb(port, ((uint8_t*)data)[i]);
+    }
 }
 
-Serial::Serial(){
+char Serial::read() {
-    // Do nothing!
+    return inb(port);
 }
 
-Serial::~Serial(){
+int Serial::is_transmit_empty() {
-    // Do nothing!
+    return inb(port + 5) & 0x20;
-}
+}
+
+

kernel/drivers/serial/serial.h

@@ -1,19 +1,29 @@
 #pragma once
+// For now these are the standard
+// serial ports we can talk to
+enum SERIALPORT {
+    COM1 = 0x3F8,
+    COM2 = 0x2F8,
+    COM3 = 0x3E8,
+    COM4 = 0x2E8
+};
 
-class Serial {
+struct SerialConfig {
+    SERIALPORT port;
+    char baud_rate_lo ;
+    char baud_rate_hi;
+};
+
+
+class Serial   {
 
     public: 
-        static Serial init();
+        Serial (SerialConfig config );
-        
-        void print();
 
-    private: 
+        char read();
-        const int COM1 = 0x3F8;
+        void write(void* data, int length);
-        const int COM2 = 0x2F8;
-        const int COM3 = 0x3E8;
-        const int COM4 = 0x2E8;
 
-
+    private:
-        Serial();
+        SERIALPORT port;
-        ~Serial();
+        int is_transmit_empty();
 };

kernel/kernel.cpp

@@ -12,12 +12,11 @@
 #include "i386/processor.h"
 #include "terminal/kterm.h"
 #include "interrupts/idt.h"
-#include "serial.h"
 #include "storage/vfs/vfs.h"
 #include "storage/filesystems/FAT/FAT.h"
 #include "acpi/acpi.h"
 #include "memory/VirtualMemoryManager.h"
-
+#include "drivers/serial/serial.h"
 
 extern BootInfoBlock* BIB;
 extern "C"  void LoadGlobalDescriptorTable();
@@ -40,20 +39,16 @@ void initBootDrive(){
 
 extern "C" void kernel ()
 {
-    init_serial();
     kterm_init();
-    print_serial("kterm initialized...\n");
     setup_tss();
     initGDT();
     initidt();
     LoadGlobalDescriptorTable();
     flush_tss();
     printf("Memory setup complete!\n");
-    print_serial("Memory initialized....\n");
     // Enable interrupts
     asm volatile("STI");
     initHeap();
-    print_serial("Heap initialized...\n");
     //pit_initialise();
 
 
@@ -64,11 +59,23 @@ extern "C" void kernel ()
     initBootDrive();
     VirtualFileSystem::initialize();
 
-    print_serial("Run test!");
+
+    // Test new serial driver
+    SerialConfig debug_com1_config{
+            COM1,
+            0x03,
+            0x00
+    };
+    Serial com1 = Serial(debug_com1_config);
+
+    com1.write((void*)"Hello world!\n", 14);
+
 #define VFS_EXAMPLE
 #ifdef VFS_EXAMPLE
     auto fontFile = VirtualFileSystem::open("/FONT    PSF", 0);
-    printf("Size of font file: %d bytes", fontFile->root->size); // COOL This Works like a charm
+    printf("Size of font file: %d bytes\n", fontFile->root->size); // COOL This Works like a charm
+
+
 #endif
 
 #ifdef USERMODE_RELEASE

kernel/serial.h

@@ -1,58 +0,0 @@
-#pragma once
-
-#include "terminal/kterm.h"
-#include "io/io.h"
-#define PORT 0x3f8 
-static int init_serial() {
-
-#ifdef __VERBOSE__
-   printf("Init Serial\n");
-#endif
-   
-   outb(PORT + 1, 0x00);    // Disable all interrupts
-   outb(PORT + 3, 0x80);    // Enable DLAB (set baud rate divisor)
-   outb(PORT + 0, 0x03);    // Set divisor to 3 (lo byte) 38400 baud
-   outb(PORT + 1, 0x00);    //                  (hi byte)
-   outb(PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
-   outb(PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
-   outb(PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
-   outb(PORT + 4, 0x1E);    // Set in loopback mode, test the serial chip
-   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(inb(PORT + 0) != 0xAE) {
-      return 1;
-   }
- 
-   // If serial is not faulty set it in normal operation mode
-   // (not-loopback with IRQs enabled and OUT#1 and OUT#2 bits enabled)
-   outb(PORT + 4, 0x0F);
-   return 0;
-}
-
-inline int is_transmit_empty() {
-   return inb(PORT + 5) & 0x20;
-}
- 
-inline void write_serial(char a) {
-   while (is_transmit_empty() == 0);
- 
-   outb(PORT,a);
-}
-
-inline int serial_received() {
-   return inb(PORT + 5) & 1;
-}
- 
-inline char read_serial() {
-   while (serial_received() == 0);
- 
-   return inb(PORT);
-}
-
-inline void print_serial(const char* string ){
-    for(size_t i = 0; i < strlen(string); i ++){
-        write_serial(string[i]);
-    }
-}
-