6 files changed, 54 insertions, 2 deletions
diff --git a/plat/arm/board/fvp/platform.mk b/plat/arm/board/fvp/platform.mk
index 4176968f8..05c11ce52 100644
--- a/plat/arm/board/fvp/platform.mk
+++ b/plat/arm/board/fvp/platform.mk
@@ -292,7 +292,7 @@ ifeq (${ARCH},aarch32)
     ifeq (${RESET_TO_SP_MIN},1)
         BL32_CFLAGS	+=	-DPLAT_XLAT_TABLES_DYNAMIC=1
     endif
-else # if AArch64
+else # AArch64
     ifeq (${RESET_TO_BL31},1)
         BL31_CFLAGS	+=	-DPLAT_XLAT_TABLES_DYNAMIC=1
     endif
@@ -301,6 +301,17 @@ else # if AArch64
     endif
 endif
 
+ifeq (${ALLOW_RO_XLAT_TABLES}, 1)
+    ifeq (${ARCH},aarch32)
+        BL32_CFLAGS	+=	-DPLAT_RO_XLAT_TABLES=1
+    else # AArch64
+        BL31_CFLAGS	+=	-DPLAT_RO_XLAT_TABLES=1
+        ifeq (${SPD},tspd)
+            BL32_CFLAGS	+=	-DPLAT_RO_XLAT_TABLES=1
+        endif
+    endif
+endif
+
 ifeq (${USE_DEBUGFS},1)
     BL31_CFLAGS	+=	-DPLAT_XLAT_TABLES_DYNAMIC=1
 endif
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index 27650d266..f07c1b163 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -155,6 +155,14 @@ else
     endif
 endif
 
+ifeq (${ALLOW_RO_XLAT_TABLES}, 1)
+    ifeq (${JUNO_AARCH32_EL3_RUNTIME}, 1)
+        BL32_CFLAGS	+=	-DPLAT_RO_XLAT_TABLES=1
+    else
+        BL31_CFLAGS	+=	-DPLAT_RO_XLAT_TABLES=1
+    endif
+endif
+
 # Add the FDT_SOURCES and options for Dynamic Config
 FDT_SOURCES		+=	plat/arm/board/juno/fdts/${PLAT}_fw_config.dts
 TB_FW_CONFIG		:=	${BUILD_PLAT}/fdts/${PLAT}_fw_config.dtb
diff --git a/plat/arm/common/arm_bl31_setup.c b/plat/arm/common/arm_bl31_setup.c
index c135d7f2d..85535c11a 100644
--- a/plat/arm/common/arm_bl31_setup.c
+++ b/plat/arm/common/arm_bl31_setup.c
@@ -256,9 +256,14 @@ void arm_bl31_plat_runtime_setup(void)
 
 	/* Initialize the runtime console */
 	arm_console_runtime_init();
+
 #if RECLAIM_INIT_CODE
 	arm_free_init_memory();
 #endif
+
+#if PLAT_RO_XLAT_TABLES
+	arm_xlat_make_tables_readonly();
+#endif
 }
 
 #if RECLAIM_INIT_CODE
diff --git a/plat/arm/common/arm_common.c b/plat/arm/common/arm_common.c
index d1e9620de..d1eee08d1 100644
--- a/plat/arm/common/arm_common.c
+++ b/plat/arm/common/arm_common.c
@@ -25,6 +25,26 @@
  * conflicts with the definition in plat/common. */
 #pragma weak plat_get_syscnt_freq2
 
+/*******************************************************************************
+ * Changes the memory attributes for the region of mapped memory where the BL
+ * image's translation tables are located such that the tables will have
+ * read-only permissions.
+ ******************************************************************************/
+#if PLAT_RO_XLAT_TABLES
+void arm_xlat_make_tables_readonly(void)
+{
+	int rc = xlat_make_tables_readonly();
+
+	if (rc != 0) {
+		ERROR("Failed to make translation tables read-only at EL%u.\n",
+		      get_current_el());
+		panic();
+	}
+
+	INFO("Translation tables are now read-only at EL%u.\n",
+	     get_current_el());
+}
+#endif
 
 void arm_setup_romlib(void)
 {
diff --git a/plat/arm/common/sp_min/arm_sp_min_setup.c b/plat/arm/common/sp_min/arm_sp_min_setup.c
index 0cc746b10..cbbdfa21b 100644
--- a/plat/arm/common/sp_min/arm_sp_min_setup.c
+++ b/plat/arm/common/sp_min/arm_sp_min_setup.c
@@ -167,6 +167,10 @@ void arm_sp_min_plat_runtime_setup(void)
 {
 	/* Initialize the runtime console */
 	arm_console_runtime_init();
+
+#if PLAT_RO_XLAT_TABLES
+	arm_xlat_make_tables_readonly();
+#endif
 }
 
 /*******************************************************************************
diff --git a/plat/arm/common/tsp/arm_tsp_setup.c b/plat/arm/common/tsp/arm_tsp_setup.c
index aefdf89c7..5dd964de2 100644
--- a/plat/arm/common/tsp/arm_tsp_setup.c
+++ b/plat/arm/common/tsp/arm_tsp_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
  */
@@ -79,4 +79,8 @@ void tsp_plat_arch_setup(void)
 
 	setup_page_tables(bl_regions, plat_arm_get_mmap());
 	enable_mmu_el1(0);
+
+#if PLAT_RO_XLAT_TABLES
+	arm_xlat_make_tables_readonly();
+#endif
 }