Basic VM and other minor improvements.

Not complete, probably not fully debugged or optimized.

lib/syslib/vm_umap.c

@@ -0,0 +1,22 @@
+
+#include "syslib.h"
+
+#include <minix/vm.h>
+
+/*===========================================================================*
+ *                                vm_umap				     *
+ *===========================================================================*/
+PUBLIC int vm_umap(int seg, vir_bytes offset, vir_bytes len, phys_bytes *addr)
+{
+    message m;
+    int result;
+
+    m.VMU_SEG = seg;
+    m.VMU_OFFSET = offset;
+    m.VMU_LENGTH = len;
+    result = _taskcall(VM_PROC_NR, VM_UMAP, &m);
+    *addr = m.VMU_RETADDR;
+
+    return result;
+}
+