ARMv7 target is driven by ARM_ARCH_MAJOR==7

External build environment shall sets directive ARM_ARCH_MAJOR to 7
to specify a target ARMv7-A core.

As ARM-TF expects AARCH to be set, ARM_ARCH_MAJOR==7 mandates
AARCH=aarch32.

The toolchain target architecture/cpu is delegated after the platform
configuration is parsed. Platform shall define target core through
ARM_CORTEX_A<x>=yes, <x> being 5, 7, 9, 12, 15 and/or 17.

Platform can bypass ARM_CORTEX_A<x>=yes directive and provide straight
the toolchain target directive through MARCH32_DIRECTIVE.

Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>

Makefile

@@ -126,20 +126,28 @@ OD			:=	${CROSS_COMPILE}objdump
 NM			:=	${CROSS_COMPILE}nm
 PP			:=	${CROSS_COMPILE}gcc -E
 
+ifeq (${ARM_ARCH_MAJOR},7)
+target32-directive	= 	-target arm-none-eabi
+# Will set march32-directive from platform configuration
+else
+target32-directive	= 	-target armv8a-none-eabi
+march32-directive	= 	-march armv8-a
+endif
+
 ifeq ($(notdir $(CC)),armclang)
-TF_CFLAGS_aarch32	=	-target arm-arm-none-eabi -march=armv8-a
+TF_CFLAGS_aarch32	=	-target arm-arm-none-eabi $(march32-directive)
 TF_CFLAGS_aarch64	=	-target aarch64-arm-none-eabi -march=armv8-a
 else ifneq ($(findstring clang,$(notdir $(CC))),)
-TF_CFLAGS_aarch32	=	-target armv8a-none-eabi
+TF_CFLAGS_aarch32	=	$(target32-directive)
 TF_CFLAGS_aarch64	=	-target aarch64-elf
 else
-TF_CFLAGS_aarch32	=	-march=armv8-a
+TF_CFLAGS_aarch32	=	$(march32-directive)
 TF_CFLAGS_aarch64	=	-march=armv8-a
 endif
 
 TF_CFLAGS_aarch64	+=	-mgeneral-regs-only -mstrict-align
 
-ASFLAGS_aarch32		=	-march=armv8-a
+ASFLAGS_aarch32		=	$(march32-directive)
 ASFLAGS_aarch64		=	-march=armv8-a
 
 CPPFLAGS		=	${DEFINES} ${INCLUDES} -nostdinc		\
@@ -262,6 +270,10 @@ include ${PLAT_MAKEFILE_FULL}
 
 $(eval $(call MAKE_PREREQ_DIR,${BUILD_PLAT}))
 
+ifeq (${ARM_ARCH_MAJOR},7)
+include make_helpers/armv7-a-cpus.mk
+endif
+
 # Platform compatibility is not supported in AArch32
 ifneq (${ARCH},aarch32)
 # If the platform has not defined ENABLE_PLAT_COMPAT, then enable it by default

docs/firmware-design.rst

@@ -2520,6 +2520,35 @@ This Architecture Extension is targeted when ``ARM_ARCH_MAJOR`` == 8 and
    table entries for a given stage of translation for a particular translation
    regime.
 
+ARMv7
+~~~~~
+
+This Architecture Extension is targeted when ``ARM_ARCH_MAJOR`` == 7.
+
+There are several ARMv7 extensions available. Obviously the TrustZone
+extension is mandatory to support the ARM Trusted Firmware bootloader
+and runtime services.
+
+Platform implementing an ARMv7 system can to define from its target
+Cortex-A architecture through ``ARM_CORTEX_A<X> = yes`` in their
+``plaform.mk`` script. For example ``ARM_CORTEX_A15=yes`` for a
+Cortex-A15 target.
+
+Platform can also set ``ARM_WITH_NEON=yes`` to enable neon support.
+Note that using neon at runtime has constraints on non secure wolrd context.
+The trusted firmware does not yet provide VFP context management.
+
+Directive ``ARM_CORTEX_A<x>`` and ``ARM_WITH_NEON`` are used to set
+the toolchain  target architecture directive.
+
+Platform may choose to not define straight the toolchain target architecture
+directive by defining ``MARCH32_DIRECTIVE``.
+I.e:
+
+::
+
+   MARCH32_DIRECTIVE := -mach=armv7-a
+
 Code Structure
 --------------
 

docs/user-guide.rst

@@ -219,7 +219,8 @@ Common build options
 
 -  ``ARM_ARCH_MAJOR``: The major version of ARM Architecture to target when
    compiling ARM Trusted Firmware. Its value must be numeric, and defaults to
-   8 . See also, *ARMv8 Architecture Extensions* in `Firmware Design`_.
+   8 . See also, *ARMv8 Architecture Extensions* and
+   *ARMv7 Architecture Extensions* in `Firmware Design`_.
 
 -  ``ARM_ARCH_MINOR``: The minor version of ARM Architecture to target when
    compiling ARM Trusted Firmware. Its value must be a numeric, and defaults

maintainers.rst

@@ -91,6 +91,11 @@ Files:
 -  docs/plat/xilinx-zynqmp.md
 -  plat/xilinx/\*
 
+ARMv7 architecture sub-maintainer
+---------------------------------
+
+Etienne Carriere (etienne.carriere@linaro.org, `etienne-lms`_)
+
 .. _danh-arm: https://github.com/danh-arm
 .. _davidcunado-arm: https://github.com/davidcunado-arm
 .. _jenswi-linaro: https://github.com/jenswi-linaro
@@ -100,3 +105,4 @@ Files:
 .. _TonyXie06: https://github.com/TonyXie06
 .. _rkchrome: https://github.com/rkchrome
 .. _sorenb-xlnx: https://github.com/sorenb-xlnx
+.. _etienne-lms: https://github.com/etienne-lms

make_helpers/armv7-a-cpus.mk

@@ -0,0 +1,33 @@
+#
+# Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+ifneq (${ARCH},aarch32)
+$(error ARM_ARCH_MAJOR=7 mandates ARCH=aarch32)
+endif
+
+# For ARMv7, set march32 from platform directive ARMV7_CORTEX_Ax=yes
+# and ARM_WITH_NEON=yes/no.
+#
+# GCC and Clang require -march=armv7-a for C-A9 and -march=armv7ve for C-A15.
+# armClang requires -march=armv7-a for all ARMv7 Cortex-A. To comply with
+# all, just drop -march and supply only -mcpu.
+
+# Platform can override march32-directive through MARCH32_DIRECTIVE
+ifdef MARCH32_DIRECTIVE
+march32-directive		:= $(MARCH32_DIRECTIVE)
+else
+march32-set-${ARM_CORTEX_A5}	:= -mcpu=cortex-a5
+march32-set-${ARM_CORTEX_A7}	:= -mcpu=cortex-a7
+march32-set-${ARM_CORTEX_A9}	:= -mcpu=cortex-a9
+march32-set-${ARM_CORTEX_A12}	:= -mcpu=cortex-a12
+march32-set-${ARM_CORTEX_A15}	:= -mcpu=cortex-a15
+march32-set-${ARM_CORTEX_A17}	:= -mcpu=cortex-a17
+march32-neon-$(ARM_WITH_NEON)	:= -mfpu=neon
+
+# default to -march=armv7-a as target directive
+march32-set-yes			?= -march=armv7-a
+march32-directive		:= ${march32-set-yes} ${march32-neon-yes}
+endif