Basic serial support

kernel/include/serial.hpp

@@ -0,0 +1,20 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#ifndef SERIAL_H
+#define SERIAL_H
+
+namespace serial {
+
+void init();
+
+bool is_transmit_buffer_empty();
+void transmit(char a);
+
+} //end of serial namespace
+
+#endif

kernel/src/kernel.cpp

@@ -12,6 +12,7 @@
 #include "kalloc.hpp"
 #include "timer.hpp"
 #include "keyboard.hpp"
+#include "serial.hpp"
 #include "disks.hpp"
 #include "acpi.hpp"
 #include "interrupts.hpp"
@@ -85,6 +86,7 @@ void  kernel_main(){
     kalloc::finalize();
 
     //Install drivers
+    serial::init();
     timer::install();
     //acpi::init();
     keyboard::install_driver();
@@ -94,7 +96,7 @@ void  kernel_main(){
     vfs::init();
 
     //Starting from here, the logging system can output logs to file
-    logging::to_file();
+    //TODO logging::to_file();
 
     //Only install system calls when everything else is ready
     install_system_calls();

kernel/src/serial.cpp

@@ -0,0 +1,31 @@
+//=======================================================================
+// Copyright Baptiste Wicht 2013-2014.
+// Distributed under the Boost Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or copy at
+//  http://www.boost.org/LICENSE_1_0.txt)
+//=======================================================================
+
+#include "serial.hpp"
+#include "kernel_utils.hpp"
+
+#define COM1_PORT 0x3f8
+
+void serial::init() {
+   out_byte(COM1_PORT + 1, 0x00);    // Disable all interrupts
+   out_byte(COM1_PORT + 3, 0x80);    // Enable DLAB
+   out_byte(COM1_PORT + 0, 0x03);    // 38400 baud
+   out_byte(COM1_PORT + 1, 0x00);
+   out_byte(COM1_PORT + 3, 0x03);    // 8 bits, no parity, one stop bit
+   out_byte(COM1_PORT + 2, 0xC7);    // Enable FIFO, clear them, with 14-byte threshold
+   out_byte(COM1_PORT + 4, 0x0B);    // IRQs enabled, RTS/DSR set
+}
+
+bool serial::is_transmit_buffer_empty() {
+   return in_byte(COM1_PORT + 5) & 0x20;
+}
+
+void serial::transmit(char a) {
+   while (is_transmit_buffer_empty() == 0){}
+
+   out_byte(COM1_PORT,a);
+}