arm_fpga: Add support for unknown MPIDs
This patch allows the system to fallback to a default CPU library
in case the MPID does not match with any of the supported ones.
This feature can be enabled by setting SUPPORT_UNKNOWN_MPID build
option to 1 (enabled by default only on arm_fpga platform).
This feature can be very dangerous on a production image and
therefore it MUST be disabled for Release images.
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I0df7ef2b012d7d60a4fd5de44dea1fbbb46881ba
diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 735d1fc..cd6549b 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -7,6 +7,12 @@
################################################################################
# Include Makefile for the SPM-MM implementation
################################################################################
+ifeq (${SUPPORT_UNKNOWN_MPID},1)
+ ifeq (${DEBUG},0)
+ $(warning WARNING: SUPPORT_UNKNOWN_MPID enabled)
+ endif
+endif
+
ifeq (${SPM_MM},1)
ifeq (${EL3_EXCEPTION_HANDLING},0)
$(error EL3_EXCEPTION_HANDLING must be 1 for SPM-MM support)
diff --git a/bl31/bl31_main.c b/bl31/bl31_main.c
index 92a2027..44bf32c 100644
--- a/bl31/bl31_main.c
+++ b/bl31/bl31_main.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -41,6 +41,15 @@
******************************************************************************/
static uint32_t next_image_type = NON_SECURE;
+#ifdef SUPPORT_UNKNOWN_MPID
+/*
+ * Flag to know whether an unsupported MPID has been detected. To avoid having it
+ * landing on the .bss section, it is initialized to a non-zero value, this way
+ * we avoid potential WAW hazards during system bring up.
+ * */
+volatile uint32_t unsupported_mpid_flag = 1;
+#endif
+
/*
* Implement the ARM Standard Service function to get arguments for a
* particular service.
@@ -98,6 +107,12 @@
NOTICE("BL31: %s\n", version_string);
NOTICE("BL31: %s\n", build_message);
+#ifdef SUPPORT_UNKNOWN_MPID
+ if (unsupported_mpid_flag == 0) {
+ NOTICE("Unsupported MPID detected!\n");
+ }
+#endif
+
/* Perform platform setup in BL31 */
bl31_platform_setup();