kbuild: use Linux Kernel build scripts

Now we are ready to switch over to real Kbuild.

This commit disables temporary scripts:
  scripts/{Makefile.build.tmp, Makefile.host.tmp}
and enables real Kbuild scripts:
  scripts/{Makefile.build,Makefile.host,Makefile.lib}.

This switch is triggered by the line in scripts/Kbuild.include
  -build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build.tmp obj
  +build := -f $(if $(KBUILD_SRC),$(srctree)/)scripts/Makefile.build obj

We need to adjust some build scripts for U-Boot.
But smaller amount of modification is preferable.

Additionally, we need to fix compiler flags which are
locally added or removed.

In Kbuild, it is not allowed to change CFLAGS locally.
Instead, ccflags-y, asflags-y, cppflags-y,
CFLAGS_$(basetarget).o, CFLAGS_REMOVE_$(basetarget).o
are prepared for that purpose.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>

1 files changed, 200 insertions, 39 deletions

diff --git a/Makefile b/Makefile
index 1409c8b..4f00f08 100644
--- a/Makefile
+++ b/Makefile
@@ -43,6 +43,78 @@ else
 XECHO = :
 endif
 
+# *DOCUMENTATION*
+# To see a list of typical targets execute "make help"
+# More info can be located in ./README
+# Comments in this file are targeted only to the developer, do not
+# expect to learn how to build the kernel reading this file.
+
+# Do not:
+# o  use make's built-in rules and variables
+#    (this increases performance and avoids hard-to-debug behaviour);
+# o  print "Entering directory ...";
+MAKEFLAGS += -rR --no-print-directory
+
+# Avoid funny character set dependencies
+unexport LC_ALL
+LC_COLLATE=C
+LC_NUMERIC=C
+export LC_COLLATE LC_NUMERIC
+
+# We are using a recursive build, so we need to do a little thinking
+# to get the ordering right.
+#
+# Most importantly: sub-Makefiles should only ever modify files in
+# their own directory. If in some directory we have a dependency on
+# a file in another dir (which doesn't happen often, but it's often
+# unavoidable when linking the built-in.o targets which finally
+# turn into vmlinux), we will call a sub make in that other dir, and
+# after that we are sure that everything which is in that other dir
+# is now up to date.
+#
+# The only cases where we need to modify files which have global
+# effects are thus separated out and done before the recursive
+# descending is started. They are now explicitly listed as the
+# prepare rule.
+
+# To put more focus on warnings, be less verbose as default
+# Use 'make V=1' to see the full commands
+
+ifeq ("$(origin V)", "command line")
+  KBUILD_VERBOSE = $(V)
+endif
+ifndef KBUILD_VERBOSE
+  KBUILD_VERBOSE = 0
+endif
+
+# Call a source code checker (by default, "sparse") as part of the
+# C compilation.
+#
+# Use 'make C=1' to enable checking of only re-compiled files.
+# Use 'make C=2' to enable checking of *all* source files, regardless
+# of whether they are re-compiled or not.
+#
+# See the file "Documentation/sparse.txt" for more details, including
+# where to get the "sparse" utility.
+
+ifeq ("$(origin C)", "command line")
+  KBUILD_CHECKSRC = $(C)
+endif
+ifndef KBUILD_CHECKSRC
+  KBUILD_CHECKSRC = 0
+endif
+
+# Use make M=dir to specify directory of external module to build
+# Old syntax make ... SUBDIRS=$PWD is still supported
+# Setting the environment variable KBUILD_EXTMOD take precedence
+ifdef SUBDIRS
+  KBUILD_EXTMOD ?= $(SUBDIRS)
+endif
+
+ifeq ("$(origin M)", "command line")
+  KBUILD_EXTMOD := $(M)
+endif
+
 # kbuild supports saving output files in a separate directory.
 # To locate output files in a separate directory two syntaxes are supported.
 # In both cases the working directory must be the root of the kernel src.
@@ -107,8 +179,14 @@ endif # ifeq ($(KBUILD_SRC),)
 # We process the rest of the Makefile if this is the final invocation of make
 ifeq ($(skip-makefile),)
 
+# If building an external module we do not care about the all: rule
+# but instead _all depend on modules
 PHONY += all
+ifeq ($(KBUILD_EXTMOD),)
 _all: all
+else
+_all: modules
+endif
 
 srctree		:= $(if $(KBUILD_SRC),$(KBUILD_SRC),$(CURDIR))
 objtree		:= $(CURDIR)
@@ -119,24 +197,6 @@ VPATH		:= $(srctree)$(if $(KBUILD_EXTMOD),:$(KBUILD_EXTMOD))
 
 export srctree objtree VPATH
 
-# Call a source code checker (by default, "sparse") as part of the
-# C compilation.
-#
-# Use 'make C=1' to enable checking of re-compiled files.
-#
-# See the linux kernel file "Documentation/sparse.txt" for more details,
-# including where to get the "sparse" utility.
-
-ifdef C
-ifeq ("$(origin C)", "command line")
-CHECKSRC := $(C)
-endif
-endif
-ifndef CHECKSRC
-  CHECKSRC = 0
-endif
-export CHECKSRC
-
 OBJTREE		:= $(objtree)
 SPLTREE		:= $(OBJTREE)/spl
 TPLTREE		:= $(OBJTREE)/tpl
@@ -222,6 +282,78 @@ HOSTCFLAGS  += $(call os_x_before, 10, 4, "-traditional-cpp")
 HOSTLDFLAGS += $(call os_x_before, 10, 5, "-multiply_defined suppress")
 endif
 
+# Decide whether to build built-in, modular, or both.
+# Normally, just do built-in.
+
+KBUILD_MODULES :=
+KBUILD_BUILTIN := 1
+
+#	If we have only "make modules", don't compile built-in objects.
+#	When we're building modules with modversions, we need to consider
+#	the built-in objects during the descend as well, in order to
+#	make sure the checksums are up to date before we record them.
+
+ifeq ($(MAKECMDGOALS),modules)
+  KBUILD_BUILTIN := $(if $(CONFIG_MODVERSIONS),1)
+endif
+
+#	If we have "make <whatever> modules", compile modules
+#	in addition to whatever we do anyway.
+#	Just "make" or "make all" shall build modules as well
+
+# U-Boot does not need modules
+#ifneq ($(filter all _all modules,$(MAKECMDGOALS)),)
+#  KBUILD_MODULES := 1
+#endif
+
+#ifeq ($(MAKECMDGOALS),)
+#  KBUILD_MODULES := 1
+#endif
+
+export KBUILD_MODULES KBUILD_BUILTIN
+export KBUILD_CHECKSRC KBUILD_SRC KBUILD_EXTMOD
+
+# Beautify output
+# ---------------------------------------------------------------------------
+#
+# Normally, we echo the whole command before executing it. By making
+# that echo $($(quiet)$(cmd)), we now have the possibility to set
+# $(quiet) to choose other forms of output instead, e.g.
+#
+#         quiet_cmd_cc_o_c = Compiling $(RELDIR)/$@
+#         cmd_cc_o_c       = $(CC) $(c_flags) -c -o $@ $<
+#
+# If $(quiet) is empty, the whole command will be printed.
+# If it is set to "quiet_", only the short version will be printed. 
+# If it is set to "silent_", nothing will be printed at all, since
+# the variable $(silent_cmd_cc_o_c) doesn't exist.
+#
+# A simple variant is to prefix commands with $(Q) - that's useful
+# for commands that shall be hidden in non-verbose mode.
+#
+#	$(Q)ln $@ :<
+#
+# If KBUILD_VERBOSE equals 0 then the above command will be hidden.
+# If KBUILD_VERBOSE equals 1 then the above command is displayed.
+
+ifeq ($(KBUILD_VERBOSE),1)
+  quiet =
+  Q =
+else
+  quiet=quiet_
+  Q = @
+endif
+
+# If the user is running make -s (silent mode), suppress echoing of
+# commands
+
+ifneq ($(filter s% -s%,$(MAKEFLAGS)),)
+  quiet=silent_
+endif
+
+export quiet Q KBUILD_VERBOSE
+
+
 # Look for make include files relative to root of kernel src
 MAKEFLAGS += --include-dir=$(srctree)
 
@@ -278,6 +410,31 @@ export DTC CHECK CHECKFLAGS
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS UBOOTINCLUDE
 export KBUILD_CFLAGS KBUILD_AFLAGS
 
+# When compiling out-of-tree modules, put MODVERDIR in the module
+# tree rather than in the kernel tree. The kernel tree might
+# even be read-only.
+export MODVERDIR := $(if $(KBUILD_EXTMOD),$(firstword $(KBUILD_EXTMOD))/).tmp_versions
+
+# Files to ignore in find ... statements
+
+RCS_FIND_IGNORE := \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS \
+		   -o -name .pc -o -name .hg -o -name .git \) -prune -o
+export RCS_TAR_IGNORE := --exclude SCCS --exclude BitKeeper --exclude .svn \
+			 --exclude CVS --exclude .pc --exclude .hg --exclude .git
+
+# ===========================================================================
+# Rules shared between *config targets and build targets
+
+# Basic helpers built in scripts/
+PHONY += scripts_basic
+scripts_basic:
+	$(Q)$(MAKE) $(build)=scripts/basic
+	$(Q)rm -f .tmp_quiet_recordmcount
+
+# To avoid any implicit rule to kick in, define an empty command.
+scripts/basic/%: scripts_basic ;
+
+
 KBUILD_CFLAGS += -Os #-fomit-frame-pointer
 
 ifdef BUILD_TAG
@@ -333,6 +490,10 @@ endif
 endif
 endif
 
+# FIX ME
+cpp_flags := $(KBUILD_CPPFLAGS) $(CPPFLAGS) $(UBOOTINCLUDE) $(NOSTDINC_FLAGS)
+c_flags := $(KBUILD_CFLAGS) $(cpp_flags)
+
 # If board code explicitly specified LDSCRIPT or CONFIG_SYS_LDSCRIPT, use
 # that (or fail if absent).  Otherwise, search for a linker script in a
 # standard location.
@@ -446,12 +607,12 @@ LIBS := $(sort $(LIBS-y))
 # Add GCC lib
 ifdef USE_PRIVATE_LIBGCC
 ifeq ("$(USE_PRIVATE_LIBGCC)", "yes")
-PLATFORM_LIBGCC = $(OBJTREE)/arch/$(ARCH)/lib/libgcc.o
+PLATFORM_LIBGCC = $(OBJTREE)/arch/$(ARCH)/lib/lib.a
 else
 PLATFORM_LIBGCC = -L $(USE_PRIVATE_LIBGCC) -lgcc
 endif
 else
-PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(CFLAGS) -print-libgcc-file-name`) -lgcc
+PLATFORM_LIBGCC := -L $(shell dirname `$(CC) $(c_flags) -print-libgcc-file-name`) -lgcc
 endif
 PLATFORM_LIBS += $(PLATFORM_LIBGCC)
 export PLATFORM_LIBS
@@ -701,7 +862,7 @@ u-boot:	depend $(SUBDIR_TOOLS) $(OBJS) $(LIBS) u-boot.lds
 ifeq ($(CONFIG_KALLSYMS),y)
 		smap=`$(call SYSTEM_MAP,u-boot) | \
 			awk '$$2 ~ /[tTwW]/ {printf $$1 $$3 "\\\\000"}'` ; \
-		$(CC) $(CFLAGS) -DSYSTEM_MAP="\"$${smap}\"" \
+		$(CC) $(c_flags) -DSYSTEM_MAP="\"$${smap}\"" \
 			-c $(srctree)/common/system_map.c -o common/system_map.o
 		$(GEN_UBOOT) common/system_map.o
 endif
@@ -709,27 +870,27 @@ endif
 $(OBJS):
 	@:
 
-$(LIBS):	depend $(SUBDIR_TOOLS)
-		$(MAKE) $(build)=$(patsubst %/,%,$(dir $@))
+$(LIBS):	depend $(SUBDIR_TOOLS) scripts_basic
+		$(Q)$(MAKE) $(build)=$(patsubst %/,%,$(dir $@))
 
-$(SUBDIRS):	depend
-		$(MAKE) $(build)=$@ all
+$(SUBDIRS):	depend scripts_basic
+		$(Q)$(MAKE) $(build)=$@
 
 $(SUBDIR_EXAMPLES-y): u-boot
 
 u-boot.lds: $(LDSCRIPT) depend
-		$(CPP) $(CPPFLAGS) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$< >$@
+		$(CPP) $(cpp_flags) $(LDPPFLAGS) -ansi -D__ASSEMBLY__ -P - <$< >$@
 
-nand_spl:	$(TIMESTAMP_FILE) $(VERSION_FILE) depend
+nand_spl:	$(TIMESTAMP_FILE) $(VERSION_FILE) depend scripts_basic
 		$(MAKE) $(build)=nand_spl/board/$(BOARDDIR) all
 
 u-boot-nand.bin:	nand_spl u-boot.bin
 		cat nand_spl/u-boot-spl-16k.bin u-boot.bin > u-boot-nand.bin
 
-spl/u-boot-spl.bin:	$(SUBDIR_TOOLS) depend
+spl/u-boot-spl.bin:	$(SUBDIR_TOOLS) depend scripts_basic
 		$(MAKE) obj=spl -f $(srctree)/spl/Makefile all
 
-tpl/u-boot-tpl.bin:	$(SUBDIR_TOOLS) depend
+tpl/u-boot-tpl.bin:	$(SUBDIR_TOOLS) depend scripts_basic
 		$(MAKE) obj=tpl -f $(srctree)/spl/Makefile all CONFIG_TPL_BUILD=y
 
 # Explicitly make _depend in subdirs containing multiple targets to prevent
@@ -804,14 +965,14 @@ checkdtc:
 include/autoconf.mk.dep: include/config.h include/common.h
 	@$(XECHO) Generating $@ ; \
 	: Generate the dependancies ; \
-	$(CC) -x c -DDO_DEPS_ONLY -M $(CFLAGS) $(CPPFLAGS) \
+	$(CC) -x c -DDO_DEPS_ONLY -M $(c_flags) \
 		-MQ include/autoconf.mk $(srctree)/include/common.h > $@ || \
 		rm $@
 
 include/autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
-	$(CPP) $(CFLAGS) -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
+	$(CPP) $(c_flags) -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
 		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
 
@@ -819,7 +980,7 @@ include/autoconf.mk: include/config.h
 include/tpl-autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
-	$(CPP) $(CFLAGS) -DCONFIG_TPL_BUILD  -DCONFIG_SPL_BUILD\
+	$(CPP) $(c_flags) -DCONFIG_TPL_BUILD  -DCONFIG_SPL_BUILD\
 			-DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
 		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
@@ -827,7 +988,7 @@ include/tpl-autoconf.mk: include/config.h
 include/spl-autoconf.mk: include/config.h
 	@$(XECHO) Generating $@ ; \
 	: Extract the config macros ; \
-	$(CPP) $(CFLAGS) -DCONFIG_SPL_BUILD -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
+	$(CPP) $(c_flags) -DCONFIG_SPL_BUILD -DDO_DEPS_ONLY -dM $(srctree)/include/common.h > $@.tmp && \
 		sed -n -f $(srctree)/tools/scripts/define2mk.sed $@.tmp > $@; \
 	rm $@.tmp
 
@@ -838,7 +999,7 @@ include/generated/generic-asm-offsets.h: lib/asm-offsets.s
 lib/asm-offsets.s: include/config.h $(srctree)/lib/asm-offsets.c
 	@mkdir -p lib
 	$(CC) -DDO_DEPS_ONLY \
-		$(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
+		$(c_flags) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
 		-o $@ $(srctree)/lib/asm-offsets.c -c -S
 
 include/generated/asm-offsets.h: $(CPUDIR)/$(SOC)/asm-offsets.s
@@ -849,7 +1010,7 @@ $(CPUDIR)/$(SOC)/asm-offsets.s:	include/config.h
 	@mkdir -p $(CPUDIR)/$(SOC)
 	if [ -f $(srctree)/$(CPUDIR)/$(SOC)/asm-offsets.c ];then \
 		$(CC) -DDO_DEPS_ONLY \
-		$(CFLAGS) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
+		$(c_flags) $(CFLAGS_$(BCURDIR)/$(@F)) $(CFLAGS_$(BCURDIR)) \
 			-o $@ $(srctree)/$(CPUDIR)/$(SOC)/asm-offsets.c -c -S; \
 	else \
 		touch $@; \
@@ -900,15 +1061,15 @@ $(TIMESTAMP_FILE):
 		@cmp -s $@ $@.tmp && rm -f $@.tmp || mv -f $@.tmp $@
 
 easylogo env gdb:
-	$(MAKE) $(build)=tools/$@ MTD_VERSION=${MTD_VERSION}
+	$(Q)$(MAKE) $(build)=tools/$@ MTD_VERSION=${MTD_VERSION}
 
 gdbtools: gdb
 
 xmldocs pdfdocs psdocs htmldocs mandocs: tools/kernel-doc/docproc
-	$(MAKE) U_BOOT_VERSION=$(U_BOOT_VERSION) $(build)=doc/DocBook $@
+	$(Q)$(MAKE) U_BOOT_VERSION=$(U_BOOT_VERSION) $(build)=doc/DocBook $@
 
 tools-all: easylogo env gdb $(VERSION_FILE) $(TIMESTAMP_FILE)
-	$(MAKE) $(build)=tools HOST_TOOLS_ALL=y
+	$(Q)$(MAKE) $(build)=tools HOST_TOOLS_ALL=y
 
 .PHONY : CHANGELOG
 CHANGELOG:
@@ -968,7 +1129,7 @@ clean:
 	@$(MAKE) -f $(srctree)/doc/DocBook/Makefile cleandocs
 	@find $(OBJTREE) -type f \
 		\( -name 'core' -o -name '*.bak' -o -name '*~' -o -name '*.su' \
-		-o -name '*.o'	-o -name '*.a' -o -name '*.exe' \
+		-o -name '*.o'	-o -name '*.a' -o -name '*.exe' -o -name '*.cmd' \
 		-o -name '*.cfgtmp' \) -print \
 		| xargs rm -f