Added support for certain control characters and hardware cursor

src/term.c

@@ -5,6 +5,7 @@
 */
 
 #include "term.h"
+#include "asm.h"
 
 uint8_t make_color(enum vga_color fg, enum vga_color bg) 
 {
@@ -26,6 +27,15 @@ size_t terminal_column;
 uint8_t terminal_color;
 uint16_t* terminal_buffer;
 
+void update_csr()
+{
+    unsigned temp = terminal_row*80+terminal_column;
+    outb(0x3D4,14);
+    outb(0x3D5,temp>>8);
+    outb(0x3D4, 15);
+    outb(0x3D5, temp);
+}
+
 void terminal_initialize() 
 {
     terminal_row = 0;
@@ -55,15 +65,38 @@ void terminal_putentryat(char c, uint8_t color, size_t x, size_t y)
 
 void terminal_putchar(char c) 
 {
-    terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
-    if (++terminal_column == VGA_WIDTH) 
+    if(c=='\b')
+    {
+	if(terminal_column == 0)
+	{
+	    terminal_row--;
+	    terminal_column=VGA_WIDTH;
+	}
+	terminal_column--;
+	terminal_putentryat(' ',terminal_color, terminal_column,terminal_row);
+    }
+    else if(c=='\n')
+    {
+	terminal_column=0;
+	terminal_row++;
+    }
+    else if(c=='\t')
+    {
+	terminal_writestring("    ");
+    }
+    else
     {
-	terminal_column = 0;
-	if (++terminal_row == VGA_HEIGHT) 
+	terminal_putentryat(c, terminal_color, terminal_column, terminal_row);
+	if (++terminal_column == VGA_WIDTH) 
 	{
-	    terminal_row = 0;
+	    terminal_column = 0;
+	    if (++terminal_row == VGA_HEIGHT) 
+	    {
+		terminal_row = 0;
+	    }
 	}
     }
+    update_csr();
 }
 
 void terminal_writestring(const char* data)