Introduce stage-specific architecture for coreboot

Make all three coreboot stages (bootblock, romstage and ramstage) aware of the
architecture specific to that stage i.e. we will have CONFIG_ARCH variables for
each of the three stages. This allows us to have an SOC with any combination of
architectures and thus every stage can be made to run on a completely different
architecture independent of others. Thus, bootblock can have an x86 arch whereas
romstage and ramstage can have arm32 and arm64 arch respectively. These stage
specific CONFIG_ARCH_ variables enable us to select the proper set of toolchain
and compiler flags for every stage.

These options can be considered as either arch or modes eg: x86 running in
different modes or ARM having different arch types (v4, v7, v8). We have got rid
of the original CONFIG_ARCH option completely as every stage can have any
architecture of its own. Thus, almost all the components of coreboot are
identified as being part of one of the three stages (bootblock, romstage or
ramstage). The components which cannot be classified as such e.g. smm, rmodules
can have their own compiler toolset which is for now set to *_i386. Hence, all
special classes are treated in a similar way and the compiler toolset is defined
using create_class_compiler defined in Makefile.

In order to meet these requirements, changes have been made to CC, LD, OBJCOPY
and family to add CC_bootblock, CC_romstage, CC_ramstage and similarly others.
Additionally, CC_x86_32 and CC_armv7 handle all the special classes. All the
toolsets are defined using create_class_compiler.

Few additional macros have been introduced to identify the class to be used at
various points, e.g.: CC_$(class) derives the $(class) part from the name of
the stage being compiled.

We have also got rid of COREBOOT_COMPILER, COREBOOT_ASSEMBLER and COREBOOT_LINKER
as they do not make any sense for coreboot as a whole. All these attributes are
associated with each of the stages.

Change-Id: I923f3d4fb097d21071030b104c372cc138c68c7b
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: http://review.coreboot.org/5577
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@gmail.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/toolchain.inc b/toolchain.inc
new file mode 100644
index 0000000000..649d2033bb
--- /dev/null
+++ b/toolchain.inc
@@ -0,0 +1,89 @@
+##
+## This file is part of the coreboot project.
+##
+## Copyright (C) 2014 Google Inc
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; version 2 of the License.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, write to the Free Software
+## Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+##
+
+ARCH_SUPPORTED := ARMV7 X86_32
+
+ARCH_TO_TOOLCHAIN_X86_32 := x86_32
+ARCH_TO_TOOLCHAIN_ARMV7  := armv7
+
+COREBOOT_STANDARD_STAGES := bootblock romstage ramstage
+
+ARCHDIR-i386    := x86
+ARCHDIR-x86_32  := x86
+ARCHDIR-armv7   := armv7
+
+CFLAGS_armv7 = \
+	-ffixed-r8\
+	-march=armv7-a\
+	-marm\
+	-mno-unaligned-access\
+	-mthumb\
+	-mthumb-interwork
+
+toolchain_to_dir = \
+	$(foreach arch,$(ARCH_SUPPORTED),\
+	$(eval INCLUDES_$(ARCH_TO_TOOLCHAIN_$(arch)) = \
+	-Isrc/arch/$(ARCHDIR-$(ARCH_TO_TOOLCHAIN_$(arch)))/include))
+
+# set_stage_toolchain: Decides the toolchain to be used by every stage
+# E.g.: If bootblock is x86_32, it sets ARCH-BOOTBLOCK-y = x86_32, whereas
+# ARCH-BOOTBLOCK-n = armv7. Then, ARCH-BOOTBLOCK-y can be used anywhere to
+# decide the compiler toolchain for bootblock stage
+# This step is essential for initializing the toolchain for coreboot standard
+# stages i.e. bootblock, romstage and ramstage, since it acts as the second
+# parameter to create_class_compiler below in init_standard_toolchain
+set_stage_toolchain= \
+	$(foreach arch,$(ARCH_SUPPORTED),$(eval ARCH-$(1)-$(CONFIG_ARCH_$(1)_$(arch)) := $(ARCH_TO_TOOLCHAIN_$(arch))))
+
+# create_class_compiler: Used to create compiler tool set for
+# special classes
+# @1: special class
+# @2: compiler set to be used
+# e.g.: smm special class uses i386 as compiler set
+define create_class_compiler
+CC_$(1) := $(CC_$(2))
+LD_$(1) := $(LD_$(2))
+NM_$(1) := $(NM_$(2))
+OBJCOPY_$(1) := $(OBJCOPY_$(2))
+OBJDUMP_$(1) := $(OBJDUMP_$(2))
+STRIP_$(1) := $(STRIP_$(2))
+READELF_$(1) := $(READELF_$(2))
+INCLUDES_$(1) = -Isrc/arch/$(ARCHDIR-$(2))/include
+CFLAGS_$(1) = $$(CFLAGS_common) $$(INCLUDES_$(1)) $(CFLAGS_$(2))
+LIBGCC_FILE_NAME_$(1) = $(shell test -r `$(CC_$(2)) -print-libgcc-file-name` && \
+	$(CC_$(2)) -print-libgcc-file-name)
+endef
+
+# initialize standard toolchain (CC,AS and others) for give stage
+# @1 : stage for which the toolchain is to be initialized
+init_standard_toolchain = \
+	$(eval stage_caps := $(shell tr '[:lower:]' '[:upper:]' <<< $(1))) \
+	$(eval $(call set_stage_toolchain,$(stage_caps))) \
+	$(eval $(call create_class_compiler,$(1),$(ARCH-$(stage_caps)-y))) \
+	$(eval $(call set_stage_libgcc,$(1)))
+
+init_stages = \
+	    $(foreach stage,$(COREBOOT_STANDARD_STAGES),$(eval $(call init_standard_toolchain,$(stage))))
+
+# This mapping is created to have consistency with xcompile naming
+$(eval $(call create_class_compiler,x86_32,i386))
+
+$(eval $(call toolchain_to_dir))
+
+$(call init_stages)