From eafbf23b6e2419595eeee3ca08e0f7a714126ec1 Mon Sep 17 00:00:00 2001
From: Baptiste Wicht <baptiste.wicht@gmail.com>
Date: Sat, 8 Feb 2014 17:24:49 +0100
Subject: [PATCH] Prepare malloc support

---
 userlib/include/malloc.hpp | 20 +++++++++++++++++
 userlib/src/malloc.cpp     | 45 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 65 insertions(+)
 create mode 100644 userlib/include/malloc.hpp
 create mode 100644 userlib/src/malloc.cpp

diff --git a/userlib/include/malloc.hpp b/userlib/include/malloc.hpp
new file mode 100644
index 00000000..1e7fcf6f
--- /dev/null
+++ b/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
diff --git a/userlib/src/malloc.cpp b/userlib/src/malloc.cpp
new file mode 100644
index 00000000..385d981a
--- /dev/null
+++ b/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;
+}