Prepare exit support

kernel/src/system_calls.cpp

@@ -40,6 +40,10 @@ void system_call_entry(const interrupt::syscall_regs& regs){
             sc_print_digit(regs);
             break;
 
+        case 0x666:
+            //TODO Indicate to the scheduler that the process is over
+            break;
+
         default:
             k_print_line("Invalid system call");
             break;

programs/one/src/main.cpp

@@ -6,10 +6,13 @@
 //=======================================================================
 
 #include <print.hpp>
+#include <system.hpp>
 
 int main(){
     print('Z');
     print_line();
 
+
+    exit(0);
     return 1;
 }

userlib/include/system.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 USER_SYSTEM_HPP
+#define USER_SYSTEM_HPP
+
+#include <types.hpp>
+
+void exit(size_t return_code){
+    asm volatile("mov rax, 0x666; mov rbx, %0; int 50"
+        : //No outputs
+        : "r" (return_code)
+        : "rax", "rbx");
+}
+
+#endif