arm: Shorten the Firmware Update (FWU) process

The watchdog is configured with a default value of 256 seconds in order
to implement the Trusted Board Boot Requirements.

For the FVP and Juno platforms, the FWU process relies on a watchdog
reset. In order to automate the test of FWU, the length of this process
needs to be as short as possible. Instead of waiting for those 4 minutes
to have a reset by the watchdog, tell it to reset immediately.

There are no side effects as the value of the watchdog's load register
resets to 0xFFFFFFFF.

Tested on Juno.

Change-Id: Ib1aea80ceddc18ff1e0813a5b98dd141ba8a3ff2
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
diff --git a/plat/arm/board/rdn1edge/platform.mk b/plat/arm/board/rdn1edge/platform.mk
index cacdaa1..b44c70a 100644
--- a/plat/arm/board/rdn1edge/platform.mk
+++ b/plat/arm/board/rdn1edge/platform.mk
@@ -12,10 +12,12 @@
 
 SGI_CPU_SOURCES		:=	lib/cpus/aarch64/neoverse_n1.S
 
-BL1_SOURCES		+=	${SGI_CPU_SOURCES}
+BL1_SOURCES		+=	${SGI_CPU_SOURCES}			\
+				${RDN1EDGE_BASE}/rdn1edge_err.c
 
 BL2_SOURCES		+=	${RDN1EDGE_BASE}/rdn1edge_plat.c	\
 				${RDN1EDGE_BASE}/rdn1edge_security.c	\
+				${RDN1EDGE_BASE}/rdn1edge_err.c		\
 				drivers/arm/tzc/tzc_dmc620.c		\
 				lib/utils/mem_region.c			\
 				plat/arm/common/arm_nor_psci_mem_protect.c
diff --git a/plat/arm/board/rdn1edge/rdn1edge_err.c b/plat/arm/board/rdn1edge/rdn1edge_err.c
new file mode 100644
index 0000000..cdcbf25
--- /dev/null
+++ b/plat/arm/board/rdn1edge/rdn1edge_err.c
@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2019, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <plat/arm/common/plat_arm.h>
+
+/*
+ * rdn1edge error handler
+ */
+void __dead2 plat_arm_error_handler(int err)
+{
+	while (1) {
+		wfi();
+	}
+}