Add malloc_top() that try to allocate memory at top of memory

second/bank.c

@@ -304,6 +304,28 @@ void *malloc_contiguous(size_t size)
 	return contiguous;
 }
 
+void *malloc_top(size_t size)
+{
+	void *top;
+	void* tmp;
+	long bubble;
+
+	bubble = bank_mem_avail() - size;
+	do {
+		tmp = malloc_contiguous(bubble);
+		if (tmp)
+		{
+			top = malloc(size);
+			free(tmp);
+			if (top)
+				return top;
+		}
+		bubble -= 1024 * 1024; /* decrease of 1 MB */
+	} while (bubble > 0);
+
+	return NULL;
+}
+
 #ifdef BANK_DUMP
 void bank_dump()
 {

second/bank.h

@@ -31,3 +31,4 @@ extern int logical2physical(unsigned long logical, unsigned long *physical);
 extern int physical2logical(unsigned long physical, unsigned long *logical);
 extern int check_full_in_bank(unsigned long start, unsigned long size);
 extern void *malloc_contiguous(size_t size);
+extern void *malloc_top(size_t size);