tests/fault_handler: Add fault handler test application

tests/fault_handler/Makefile

@@ -0,0 +1,17 @@
+# name of your application
+APPLICATION = fault_handler
+
+# If no BOARD is found in the environment, use this default:
+BOARD ?= native
+
+# This has to be the absolute path to the RIOT base directory:
+RIOTBASE ?= $(CURDIR)/../..
+
+# Change this to 0 show compiler invocation lines by default:
+QUIET ?= 1
+
+CFLAGS += -DDEVELHELP=1
+
+USEMODULE += xtimer
+
+include $(RIOTBASE)/Makefile.include

tests/fault_handler/main.c

@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2015 Eistec AB
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+/**
+ * @ingroup     test
+ * @{
+ *
+ * @file
+ * @brief       Minimal test application for triggering a hard fault or equivalent
+ *
+ * @author      Joakim Gebart <joakim.gebart@eistec.se>
+ *
+ * @}
+ */
+
+#include <stdio.h>
+#include <xtimer.h>
+
+#ifndef FORBIDDEN_ADDRESS
+/* Many platforms do not allow writes to address 0x00000000 */
+#define FORBIDDEN_ADDRESS (0x00000000)
+#endif /* !defined(FORBIDDEN_ADDRESS) */
+#ifndef INVALID_INSTRUCTION
+/* Random garbage may crash the program as well. */
+#define INVALID_INSTRUCTION asm volatile (".short 0xdead, 0xbeef, 0xcafe, 0xbabe\n")
+#endif /* !defined(INVALID_INSTRUCTION) */
+
+#define PRINT_MACRO(a) PRINT_MACRO2(a)
+#define PRINT_MACRO2(a) #a
+
+int main(void)
+{
+    puts("Fault handler test application");
+    printf("This application will crash by attempting to write to address 0x%08x\n", FORBIDDEN_ADDRESS);
+    puts("Waiting 1 second before crashing...");
+    xtimer_usleep(1000000);
+    puts("Write to forbidden address " PRINT_MACRO(FORBIDDEN_ADDRESS));
+    *((volatile int *) FORBIDDEN_ADDRESS) = 12345;
+    int readback = *((volatile int *) FORBIDDEN_ADDRESS);
+    printf("readback: 0x%08x\n", readback);
+    puts("We did not expect the application to survive the previous write.");
+    puts("Trying to execute an invalid instruction");
+    puts(PRINT_MACRO(INVALID_INSTRUCTION));
+    INVALID_INSTRUCTION;
+    puts("Failed to crash the program, hanging...");
+    while(1);
+    return 0;
+}