Add: nonworking serial port driver implementation

serial.c

@@ -0,0 +1,68 @@
+#include "io.h"
+#include "serial.h"
+
+void serial_configure_baud_rate(unsigned short com, unsigned short divisor)
+{
+  outb(SERIAL_LINE_CMD_PORT(com), SERIAL_LINE_ENABLE_DLAB);
+  outb(SERIAL_DATA_PORT(com), (divisor >> 8) & 0x00FF);
+  outb(SERIAL_DATA_PORT(com), divisor & 0x00FF);
+}
+
+void serial_configure_line(unsigned short com)
+{
+  /*
+  d b p   s dl
+  0 0 000 0 11 = 0x03
+  
+  Length 8 bits, no parity bit, one stop bit, break control off
+  */
+
+  outb(SERIAL_LINE_CMD_PORT(com), 0x03);
+}
+
+void serial_configure_buffer(unsigned short com)
+{
+  /*
+  lv b r d c c e
+  11 0 0 0 1 1 1 = 0xC7
+  
+  Enable FIFO, clear FIFO queues, use 14 bytes as queue size
+  */
+
+  outb(SERIAL_LINE_CMD_PORT(com), 0xC7);
+}
+
+void serial_configure_modem(unsigned short com)
+{
+  /*
+  
+  r r a l a a r d
+  0 0 0 0 0 0 1 1 = 0x03
+
+  Ready to transmit, data terminal ready
+  */
+
+  outb(SERIAL_LINE_CMD_PORT(com), 0x03);
+}
+
+int serial_is_transmit_fifo_empty(unsigned short com)
+{
+  return (inb(SERIAL_LINE_STATUS_PORT(com)) & 0x20);
+}
+
+void serial_write(const char* buf, unsigned short com)
+{
+  serial_configure_baud_rate(com, 2);
+  serial_configure_line(com);
+  serial_configure_buffer(com);
+  serial_configure_modem(com);
+
+  for (unsigned int i = 0; i<sizeof(buf); i++)
+  {
+    while (serial_is_transmit_fifo_empty(com))
+    {
+      outb(SERIAL_DATA_PORT(com), buf[i]);
+    }
+  }
+  return;
+}