libubb/physmem.c: new function physmem_flush to flush cached writes to memory

This is mainly a wrapper for the "cacheflush" system call.

libubb/include/ubb/physmem.h

@@ -0,0 +1,24 @@
+/*
+ * physmem.h - Physical memory translator and allocator
+ *
+ * Written 2013 by Werner Almesberger
+ * Copyright 2013 Werner Almesberger
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#ifndef UBB_PHYSMEM_H
+#define	UBB_PHYSMEM_H
+
+#include <sys/types.h>
+
+
+void *physmem_malloc(size_t size);
+void *physmem_calloc(size_t size);
+unsigned long physmem_xlat(void *v);
+int physmem_flush(const void *data, size_t size);
+
+#endif /* !UBB_PHYSMEM_H */