add getCursor

arch/cga.cc

@@ -8,7 +8,12 @@ namespace CGA {
 
   void writeCGAReg(int reg, int data){
     index_port.outb(reg);
-    data_port.outb(data);
+    data_port.outw(data);
+  }
+
+  uint16_t readCGAReg(int reg){
+    index_port.outb(reg);
+    return data_port.inb();
   }
 
 void setCursor(unsigned abs_x, unsigned abs_y) {
@@ -19,8 +24,11 @@ void setCursor(unsigned abs_x, unsigned abs_y) {
 }
 
 void getCursor(unsigned& abs_x, unsigned& abs_y) {
-  (void)abs_x;
-  (void)abs_y;
+  uint16_t pos = readCGAReg(RegisterIndex::CURSOR_LOW);
+  pos |= (readCGAReg(RegisterIndex::CURSOR_HIGH) << 8);
+
+  abs_x = pos / 80;
+  abs_y = pos % 80;
 }
 
 void show(unsigned abs_x, unsigned abs_y, char character, Attribute attrib) {

arch/cga.h

@@ -67,7 +67,6 @@ enum Color {
  * (`-fno-strict-aliasing`). In \StuBS we use this feature extensively due to
  * the improved code readability.
  *
- * \todo(11) Fill in the bitfield
  */
 union Attribute {
   struct {
@@ -79,8 +78,6 @@ union Attribute {
 
   /*! \brief Attribute constructor (with default values)
    *
-   *  \todo(11) Complete constructor
-   *
    *  \param foreground Foreground color (Default: \ref LIGHT_GREY)
    *  \param background Background color (Default: \ref BLACK)
    *  \param blink Blink if `true` (default: no blinking)
@@ -91,8 +88,6 @@ union Attribute {
 
 /*! \brief Set the keyboard hardware cursor to absolute screen position
  *
- *  \todo(11) Implement the method using \ref IOPort
- *
  *  \param abs_x absolute column of the keyboard hardware cursor
  *  \param abs_y absolute row of the keyboard hardware cursor
  */

main.cc

@@ -10,8 +10,13 @@ extern "C" int main() {
   unsigned int numCPUs = Core::count();
   DBG_VERBOSE << "Number of CPUs: " << numCPUs << endl;
 
-  CGA::setCursor(1, 2);
-  
+  CGA::setCursor(0, 0);
+
+  unsigned x,y;
+  CGA::getCursor(x, y);
+
+  CGA::setCursor(x+1, y+1);
+
   /* Start application processors
    * To avoid unexpected behaviour, make sure that interrupts are not
    * enabled before the APs are booted. Otherwise it might interfere with the