Added an idle function for long running functions to call.

include/system.h

@@ -10,6 +10,7 @@ extern int strlen(const char *str);
 extern unsigned char inportb (unsigned short _port);
 extern void outportb (unsigned short _port, unsigned char _data);
 extern bool strcmp(char* str1, char* str2);
+extern void idle();
 /* ISRS.C */
 void isrs_install();
 /* This defines what the stack looks like after an ISR was running */

src/main.c

@@ -115,3 +115,8 @@ void main()
     *  'start.asm' also, if you accidentally delete this next line */
     for (;;);
 }
+
+void idle()
+{
+	__asm__ __volatile__ ("hlt");
+}

src/shell.c

@@ -9,7 +9,7 @@ void run_shell()
 	puts("Starting interactive shell...\n");
 	commandbuffer[0] = '\0';
 	puts("#>");
-	for(;;);
+	for(;;) idle();
 }
 
 void key_pressed(unsigned char* character)