diff --git a/plat/arm/board/rde1edge/include/platform_def.h b/plat/arm/board/rde1edge/include/platform_def.h
index a9b30a4..69bfd7b 100644
--- a/plat/arm/board/rde1edge/include/platform_def.h
+++ b/plat/arm/board/rde1edge/include/platform_def.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2021, Arm Limited. All rights reserved.
+ * Copyright (c) 2018-2022, Arm Limited. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -26,12 +26,15 @@
 
 #define CSS_SYSTEM_PWR_DMN_LVL		ARM_PWR_LVL3
 
+/* Maximum number of address bits used per chip */
+#define CSS_SGI_ADDR_BITS_PER_CHIP	U(36)
+
 /*
  * Physical and virtual address space limits for MMU in AARCH64 & AARCH32 modes
  */
 #ifdef __aarch64__
-#define PLAT_PHY_ADDR_SPACE_SIZE	(1ULL << 36)
-#define PLAT_VIRT_ADDR_SPACE_SIZE	(1ULL << 36)
+#define PLAT_PHY_ADDR_SPACE_SIZE	(1ULL << CSS_SGI_ADDR_BITS_PER_CHIP)
+#define PLAT_VIRT_ADDR_SPACE_SIZE	(1ULL << CSS_SGI_ADDR_BITS_PER_CHIP)
 #else
 #define PLAT_PHY_ADDR_SPACE_SIZE	(1ULL << 32)
 #define PLAT_VIRT_ADDR_SPACE_SIZE	(1ULL << 32)