diff --git a/docs/plat/arm/arm-build-options.rst b/docs/plat/arm/arm-build-options.rst
index 2aa9738..79b40d1 100644
--- a/docs/plat/arm/arm-build-options.rst
+++ b/docs/plat/arm/arm-build-options.rst
@@ -132,6 +132,12 @@
    valid value greater than 1, the platform code performs required configuration
    to support multi-chip operation.
 
+- ``CSS_SGI_PLATFORM_VARIANT``: Selects the variant of a SGI/RD platform. A
+    particular SGI/RD platform may have multiple variants which may differ in
+    core count, cluster count or other peripherals. This build option is used
+    to select the appropriate platform variant for the build. The range of
+    valid values is platform specific.
+
 --------------
 
 *Copyright (c) 2019-2021, Arm Limited. All rights reserved.*
diff --git a/plat/arm/board/rde1edge/platform.mk b/plat/arm/board/rde1edge/platform.mk
index 53074f4..0f9dd49 100644
--- a/plat/arm/board/rde1edge/platform.mk
+++ b/plat/arm/board/rde1edge/platform.mk
@@ -58,4 +58,9 @@
    ${CSS_SGI_CHIP_COUNT}.")
 endif
 
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-E1-Edge should always be 0, \
+     currently set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
+
 override CTX_INCLUDE_AARCH32_REGS	:= 0
diff --git a/plat/arm/board/rdn1edge/platform.mk b/plat/arm/board/rdn1edge/platform.mk
index d65854f..22ab312 100644
--- a/plat/arm/board/rdn1edge/platform.mk
+++ b/plat/arm/board/rdn1edge/platform.mk
@@ -65,4 +65,9 @@
    set to ${CSS_SGI_CHIP_COUNT}.")
 endif
 
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-N1-Edge should always be 0, \
+     currently set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
+
 override CTX_INCLUDE_AARCH32_REGS	:= 0
diff --git a/plat/arm/board/rdn2/platform.mk b/plat/arm/board/rdn2/platform.mk
index 03771dc..bd50fa2 100644
--- a/plat/arm/board/rdn2/platform.mk
+++ b/plat/arm/board/rdn2/platform.mk
@@ -58,3 +58,8 @@
 
 override CTX_INCLUDE_AARCH32_REGS	:= 0
 override ENABLE_AMU			:= 1
+
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-N2 should be 0, currently set to \
+     ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
diff --git a/plat/arm/board/rdv1/platform.mk b/plat/arm/board/rdv1/platform.mk
index 2ffd139..1ae85de 100644
--- a/plat/arm/board/rdv1/platform.mk
+++ b/plat/arm/board/rdv1/platform.mk
@@ -58,3 +58,8 @@
 
 override CTX_INCLUDE_AARCH32_REGS	:= 0
 override ENABLE_AMU			:= 1
+
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-V1 should always be 0, \
+     currently set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
diff --git a/plat/arm/board/rdv1mc/platform.mk b/plat/arm/board/rdv1mc/platform.mk
index fb05793..06a2047 100644
--- a/plat/arm/board/rdv1mc/platform.mk
+++ b/plat/arm/board/rdv1mc/platform.mk
@@ -68,3 +68,8 @@
 $(eval $(call TOOL_ADD_PAYLOAD,${NT_FW_CONFIG},--nt-fw-config,${NT_FW_CONFIG}))
 
 override CTX_INCLUDE_AARCH32_REGS	:= 0
+
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for RD-V1-MC should always be 0, \
+     currently set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
diff --git a/plat/arm/board/sgi575/platform.mk b/plat/arm/board/sgi575/platform.mk
index 89abcfe..0761b77 100644
--- a/plat/arm/board/sgi575/platform.mk
+++ b/plat/arm/board/sgi575/platform.mk
@@ -58,3 +58,8 @@
  $(error  "Chip count for SGI575 should be 1, currently set to \
    ${CSS_SGI_CHIP_COUNT}.")
 endif
+
+ifneq ($(CSS_SGI_PLATFORM_VARIANT),0)
+ $(error "CSS_SGI_PLATFORM_VARIANT for SGI575 should always be 0,\
+     currently set to ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
diff --git a/plat/arm/css/sgi/sgi-common.mk b/plat/arm/css/sgi/sgi-common.mk
index 615f53d..1e2054f 100644
--- a/plat/arm/css/sgi/sgi-common.mk
+++ b/plat/arm/css/sgi/sgi-common.mk
@@ -18,6 +18,8 @@
 
 CSS_SGI_CHIP_COUNT		:=	1
 
+CSS_SGI_PLATFORM_VARIANT	:=	0
+
 INTERCONNECT_SOURCES	:=	${CSS_ENT_BASE}/sgi_interconnect.c
 
 PLAT_INCLUDES		+=	-I${CSS_ENT_BASE}/include
@@ -57,6 +59,8 @@
 
 $(eval $(call add_define,CSS_SGI_CHIP_COUNT))
 
+$(eval $(call add_define,CSS_SGI_PLATFORM_VARIANT))
+
 override CSS_LOAD_SCP_IMAGES	:=	0
 override NEED_BL2U		:=	no
 override ARM_BL31_IN_DRAM	:=	1