Add atexit function to libc

We had exit but we didn't have atexit, and we were calling panic and
tf_printf from exit, which generated a dependency from exit to them.
Having atexit allows to set a different function pointer in every image.

Change-Id: I95b9556d680d96249ed3b14da159b6f417da7661
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

1 files changed, 16 insertions, 4 deletions

diff --git a/lib/libc/exit.c b/lib/libc/exit.c
index afc3f934..b2fde9ca 100644
--- a/lib/libc/exit.c
+++ b/lib/libc/exit.c
@@ -4,11 +4,23 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
-#include <debug.h>
 #include <stdlib.h>
 
-void exit(int v)
+static void (*exitfun)(void);
+
+void exit(int status)
 {
-	ERROR("EXIT\n");
-	panic();
+	if (exitfun)
+		(*exitfun)();
+	for (;;)
+		;
+}
+
+int atexit(void (*fun)(void))
+{
+	if (exitfun)
+		return -1;
+	exitfun = fun;
+
+	return 0;
 }