Merge changes from topic "hm/make-refactor" into integration

* changes:
  docs(prerequisites): use LLVM utilities to build with clang
  build(make): use clang binutils to compile

Makefile

@@ -263,24 +263,24 @@ ENABLE_FEAT_RNG		=	$(if $(findstring rng,${arch-features}),1,0)
 # Determine if FEAT_SB is supported
 ENABLE_FEAT_SB		=	$(if $(findstring sb,${arch-features}),1,0)
 
-ifneq ($(findstring armclang,$(notdir $(CC))),)
+ifneq ($(findstring clang,$(notdir $(CC))),)
-TF_CFLAGS_aarch32	=	-target arm-arm-none-eabi $(march32-directive)
+	ifneq ($(findstring armclang,$(notdir $(CC))),)
-TF_CFLAGS_aarch64	=	-target aarch64-arm-none-eabi $(march64-directive)
+		TF_CFLAGS_aarch32	:=	-target arm-arm-none-eabi $(march32-directive)
-LD			=	$(LINKER)
+		TF_CFLAGS_aarch64	:=	-target aarch64-arm-none-eabi $(march64-directive)
-AS			=	$(CC) -c -x assembler-with-cpp $(TF_CFLAGS_$(ARCH))
+		LD			:=	$(LINKER)
-CPP			=	$(CC) -E $(TF_CFLAGS_$(ARCH))
+	else
-PP			=	$(CC) -E $(TF_CFLAGS_$(ARCH))
+		TF_CFLAGS_aarch32	:=	$(target32-directive) $(march32-directive)
-else ifneq ($(findstring clang,$(notdir $(CC))),)
+		TF_CFLAGS_aarch64	:=	-target aarch64-elf $(march64-directive)
-CLANG_CCDIR		=	$(if $(filter-out ./,$(dir $(CC))),$(dir $(CC)),)
+		LD			:=	$(shell $(CC) --print-prog-name ld.lld)
-TF_CFLAGS_aarch32	=	$(target32-directive) $(march32-directive)
+
-TF_CFLAGS_aarch64	=	-target aarch64-elf $(march64-directive)
+		AR			:=	$(shell $(CC) --print-prog-name llvm-ar)
-LD			=	$(CLANG_CCDIR)ld.lld
+		OD			:=	$(shell $(CC) --print-prog-name llvm-objdump)
-ifeq (, $(shell which $(LD)))
+		OC			:=	$(shell $(CC) --print-prog-name llvm-objcopy)
-$(error "No $(LD) in PATH, make sure it is installed or set LD to a different linker")
+	endif
-endif
+
-AS			=	$(CC) -c -x assembler-with-cpp $(TF_CFLAGS_$(ARCH))
+	CPP		:=	$(CC) -E $(TF_CFLAGS_$(ARCH))
-CPP			=	$(CC) -E
+	PP		:=	$(CC) -E $(TF_CFLAGS_$(ARCH))
-PP			=	$(CC) -E
+	AS		:=	$(CC) -c -x assembler-with-cpp $(TF_CFLAGS_$(ARCH))
 else ifneq ($(findstring gcc,$(notdir $(CC))),)
 TF_CFLAGS_aarch32	=	$(march32-directive)
 TF_CFLAGS_aarch64	=	$(march64-directive)

docs/getting_started/initial-build.rst

@@ -18,16 +18,12 @@ Performing an Initial Build
 
    It is possible to build TF-A using Clang or Arm Compiler 6. To do so
    ``CC`` needs to point to the clang or armclang binary, which will
-   also select the clang or armclang assembler. Be aware that for Arm Compiler,
+   also select the clang or armclang assembler. Arm Compiler 6 will be selected
-   the GNU linker is used by default. However for Clang LLVM linker (LLD)
+   when the base name of the path assigned to ``CC`` matches the string
-   is used by default. In case of being needed the linker can be overridden
+   'armclang'. GNU binutils are required since the TF-A build system doesn't
-   using the ``LD`` variable. LLVM linker (LLD) version 9 is
+   currently support Arm Scatter files. Meaning the GNU linker is used by
-   known to work with TF-A.
+   default for Arm Compiler 6. Because of this dependency, ``CROSS_COMPILE``
-
+   should be set as described above.
-   In both cases ``CROSS_COMPILE`` should be set as described above.
-
-   Arm Compiler 6 will be selected when the base name of the path assigned
-   to ``CC`` matches the string 'armclang'.
 
    For AArch64 using Arm Compiler 6:
 
@@ -36,6 +32,11 @@ Performing an Initial Build
        export CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf-
        make CC=<path-to-armclang>/bin/armclang PLAT=<platform> all
 
+   On the other hand, Clang uses LLVM linker (LLD) and other LLVM binutils by
+   default instead of GNU utilities (LLVM linker (LLD) 14.0.0 is known to
+   work with TF-A). ``CROSS_COMPILE`` need not be set for Clang. Please note,
+   that the default linker may be manually overridden using the ``LD`` variable.
+
    Clang will be selected when the base name of the path assigned to ``CC``
    contains the string 'clang'. This is to allow both clang and clang-X.Y
    to work.
@@ -44,7 +45,6 @@ Performing an Initial Build
 
    .. code:: shell
 
-       export CROSS_COMPILE=<path-to-aarch64-gcc>/bin/aarch64-none-elf-
        make CC=<path-to-clang>/bin/clang PLAT=<platform> all
 
 -  Change to the root directory of the TF-A source tree and build.
@@ -115,4 +115,4 @@ Performing an Initial Build
 
 --------------
 
-*Copyright (c) 2020, Arm Limited. All rights reserved.*
+*Copyright (c) 2020-2022, Arm Limited. All rights reserved.*

docs/getting_started/prerequisites.rst

@@ -27,8 +27,8 @@ Toolchain
 target the Armv7-A or Armv8-A architectures:
 
 - GCC >= 11.2-2022.02 (from the `Arm Developer website`_)
-- Clang >= 4.0
+- Clang >= 14.0.0
-- Arm Compiler >= 6.0
+- Arm Compiler >= 6.18
 
 In addition, a native compiler is required to build the supporting tools.
 
@@ -160,7 +160,7 @@ documentation, available `here <https://git-scm.com/docs/githooks>`_.
 
 --------------
 
-*Copyright (c) 2021, Arm Limited. All rights reserved.*
+*Copyright (c) 2021-2022, Arm Limited. All rights reserved.*
 
 .. _Arm Developer website: https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/downloads
 .. _Gerrit Code Review: https://www.gerritcodereview.com/