diff --git a/docs/plat/arm/arm-build-options.rst b/docs/plat/arm/arm-build-options.rst
index 2aa973890af3b1192203a04e329e171797300259..79b40d166c86f11a3bbc75945b26b6993810afba 100644
--- a/docs/plat/arm/arm-build-options.rst
+++ b/docs/plat/arm/arm-build-options.rst
@@ -132,6 +132,12 @@ Arm CSS Platform-Specific Build Options
    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 53074f495e8d498a9a6b19cbaa014d2d7037fe15..0f9dd496a74018b814579933efb3e9cdb696a253 100644
--- a/plat/arm/board/rde1edge/platform.mk
+++ b/plat/arm/board/rde1edge/platform.mk
@@ -58,4 +58,9 @@ ifneq ($(CSS_SGI_CHIP_COUNT),1)
    ${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 ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
+
 override CTX_INCLUDE_AARCH32_REGS	:= 0
diff --git a/plat/arm/board/rdn1edge/platform.mk b/plat/arm/board/rdn1edge/platform.mk
index d65854f8d05ccb91ad58092a65e5bed50f29e185..22ab312eefe25a1d7675ff1420c0d3100fc809c0 100644
--- a/plat/arm/board/rdn1edge/platform.mk
+++ b/plat/arm/board/rdn1edge/platform.mk
@@ -65,4 +65,9 @@ ifneq ($(CSS_SGI_CHIP_COUNT),$(filter $(CSS_SGI_CHIP_COUNT),$(SEQ)))
    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 03771dc3d18146346f4c5d53c208c1d0ff284b5d..bd50fa29b2835d19615499c609cf6875cfe0c33d 100644
--- a/plat/arm/board/rdn2/platform.mk
+++ b/plat/arm/board/rdn2/platform.mk
@@ -58,3 +58,8 @@ $(eval $(call TOOL_ADD_PAYLOAD,${NT_FW_CONFIG},--nt-fw-config))
 
 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 2ffd139c96ac07a652b3c577315823171c7b7ae8..1ae85de7c74ae2b72203a8670be87a8bccedae12 100644
--- a/plat/arm/board/rdv1/platform.mk
+++ b/plat/arm/board/rdv1/platform.mk
@@ -58,3 +58,8 @@ $(eval $(call TOOL_ADD_PAYLOAD,${NT_FW_CONFIG},--nt-fw-config,${NT_FW_CONFIG}))
 
 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 fb057936ad439643fa4ebded251d964b74f4260d..06a2047393033b912afb352d97861d81380e9985 100644
--- a/plat/arm/board/rdv1mc/platform.mk
+++ b/plat/arm/board/rdv1mc/platform.mk
@@ -68,3 +68,8 @@ NT_FW_CONFIG		:=	${BUILD_PLAT}/fdts/${PLAT}_nt_fw_config.dtb
 $(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 ${CSS_SGI_PLATFORM_VARIANT}.")
+endif
diff --git a/plat/arm/board/sgi575/platform.mk b/plat/arm/board/sgi575/platform.mk
index 89abcfe8ee5c2627ed9c6dcc4303cfe8ceec6a0a..0761b77ef2886a9a0ec8a6c1d76e89a8be9baaf1 100644
--- a/plat/arm/board/sgi575/platform.mk
+++ b/plat/arm/board/sgi575/platform.mk
@@ -58,3 +58,8 @@ ifneq ($(CSS_SGI_CHIP_COUNT),1)
  $(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 615f53dc97992b0600d6def2865527b64368d1a7..1e2054f84a7eb8ed04cb165108187289e5b6be97 100644
--- a/plat/arm/css/sgi/sgi-common.mk
+++ b/plat/arm/css/sgi/sgi-common.mk
@@ -18,6 +18,8 @@ HANDLE_EA_EL3_FIRST		:=	0
 
 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,SGI_PLAT))
 
 $(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