Prepare malloc support

userlib/include/malloc.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 USERLIB_MALLOC_H
+#define USERLIB_MALLOC_H
+
+#include "types.hpp"
+
+void* malloc(size_t size);
+void free(void* pointer);
+
+size_t brk_start();
+size_t brk_end();
+size_t sbrk(size_t inc);
+
+#endif

userlib/src/malloc.cpp

@@ -0,0 +1,45 @@
+//=======================================================================
+// 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 "malloc.hpp"
+
+void* malloc(size_t size){
+    //TODO
+
+    return nullptr;
+}
+
+void free(void* pointer){
+    //TODO
+}
+
+size_t brk_start(){
+    size_t value;
+    asm volatile("mov rax, 7; int 50; mov %0, rax"
+        : "=m" (value)
+        : //No inputs
+        : "rax");
+    return value;
+}
+
+size_t brk_end(){
+    size_t value;
+    asm volatile("mov rax, 8; int 50; mov %0, rax"
+        : "=m" (value)
+        : //No inputs
+        : "rax");
+    return value;
+}
+
+size_t sbrk(size_t inc){
+    size_t value;
+    asm volatile("mov rax, 9; int 50; mov %0, rax"
+        : "=m" (value)
+        : "b" (inc)
+        : "rax");
+    return value;
+}