plat/arm: Add support for SEPARATE_NOBITS_REGION
In order to support SEPARATE_NOBITS_REGION for Arm platforms, we need to load
BL31 PROGBITS into secure DRAM space and BL31 NOBITS into SRAM. Hence mandate
the build to require that ARM_BL31_IN_DRAM is enabled as well.
Naturally with SEPARATE_NOBITS_REGION enabled, the BL31 initialization code
cannot be reclaimed to be used for runtime data such as secondary cpu stacks.
Memory map for BL31 NOBITS region also has to be created.
Change-Id: Ibd480f82c1dc74e9cbb54eec07d7a8fecbf25433
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
diff --git a/plat/arm/common/arm_bl31_setup.c b/plat/arm/common/arm_bl31_setup.c
index 939885f..7a3ca71 100644
--- a/plat/arm/common/arm_bl31_setup.c
+++ b/plat/arm/common/arm_bl31_setup.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
@@ -56,6 +56,14 @@
MT_CODE | MT_SECURE)
#endif
+#if SEPARATE_NOBITS_REGION
+#define MAP_BL31_NOBITS MAP_REGION_FLAT( \
+ BL31_NOBITS_BASE, \
+ BL31_NOBITS_LIMIT \
+ - BL31_NOBITS_BASE, \
+ MT_MEMORY | MT_RW | MT_SECURE)
+
+#endif
/*******************************************************************************
* Return a pointer to the 'entry_point_info' structure of the next image for the
* security state specified. BL33 corresponds to the non-secure image type
@@ -295,6 +303,9 @@
#if RECLAIM_INIT_CODE
MAP_BL_INIT_CODE,
#endif
+#if SEPARATE_NOBITS_REGION
+ MAP_BL31_NOBITS,
+#endif
ARM_MAP_BL_RO,
#if USE_ROMLIB
ARM_MAP_ROMLIB_CODE,
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index 9d4f05e..ab33e1d 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -1,5 +1,5 @@
#
-# Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2015-2020, ARM Limited and Contributors. All rights reserved.
#
# SPDX-License-Identifier: BSD-3-Clause
#
@@ -125,6 +125,23 @@
# mapping the former as executable and the latter as execute-never.
SEPARATE_CODE_AND_RODATA := 1
+# On ARM platforms, disable SEPARATE_NOBITS_REGION by default. Both PROGBITS
+# and NOBITS sections of BL31 image are adjacent to each other and loaded
+# into Trusted SRAM.
+SEPARATE_NOBITS_REGION := 0
+
+# In order to support SEPARATE_NOBITS_REGION for Arm platforms, we need to load
+# BL31 PROGBITS into secure DRAM space and BL31 NOBITS into SRAM. Hence mandate
+# the build to require that ARM_BL31_IN_DRAM is enabled as well.
+ifeq ($(SEPARATE_NOBITS_REGION),1)
+ ifneq ($(ARM_BL31_IN_DRAM),1)
+ $(error For SEPARATE_NOBITS_REGION, ARM_BL31_IN_DRAM must be enabled)
+ endif
+ ifneq ($(RECLAIM_INIT_CODE),0)
+ $(error For SEPARATE_NOBITS_REGION, RECLAIM_INIT_CODE cannot be supported)
+ endif
+endif
+
# Disable ARM Cryptocell by default
ARM_CRYPTOCELL_INTEG := 0
$(eval $(call assert_boolean,ARM_CRYPTOCELL_INTEG))