Kbuild brought about many advantages for us but a significant
performance regression was reported by Simon Glass.
After some discussions and analysis, it turned out
its main cause is in $(call cc-option,...).
Historically, U-Boot parses all config.mk
(arch/*/config.mk and board/*/config.mk)
every time descending into subdirectories.
That means cc-options are evaluated over and over again.
$(call cc-option,...) is useful but costly.
So we want to evaluate them only in ./Makefile
and spl/Makefile and export compiler flags.
This commit changes the build system as follows:
- Modify scripts/Makefile.build to not include config.mk
Instead, add $(PLATFORM_CPPFLAGS) to asflags-y, ccflags-y,
cppflags-y.
- Export many variables
Going forward, Kbuild will not parse config.mk files
when it descends into subdirectories.
If we want to set variables in config.mk and use them
in subdirectories, they must be exported.
This is the list of variables to get exported:
PLATFORM_CPPFLAGS
CPUDIR
BOARDDIR
OBJCOPYFLAGS
LDFLAGS
LDFLAGS_FINAL
(used in nand_spl/board/*/*/Makefile)
CONFIG_STANDALONE_LOAD_ADDR
(used in examples/standalone/Makefile)
SYM_PREFIX
(used in examples/standalone/Makefile)
RELFLAGS
(used in examples/standalone/Makefile)
- Delete CPPFLAGS
This variable has been replaced with PLATFORM_CPPFLAGS
- Copy gcclibdir from example/standalone/Makefile
to arch/sparc/config.mk
The reference in CONFIG_STANDALONE_LOAD_ADDR must be
resolved before it is exported.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Reported-by: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org> [on Sandbox]
Tested-by: Stephen Warren <swarren@nvidia.com> [on Tegra]
The syntax
CROSS_COMIPLE ?= <cross_compiler_prefix>
does not work because config.mk is parsed after
exporting CROSS_COMPILE.
Like Linux Kernel's arch/$(ARCH)/Makefile,
we must write as follows:
ifeq ($(CROSS_COMPILE),)
CROSS_COMPILE := <cross_compiler_prefix>
endif
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
This commit changes the working directory
where the build process occurs.
Before this commit, build process occurred under the source
tree for both in-tree and out-of-tree build.
That's why we needed to add $(obj) prefix to all generated
files in makefiles like follows:
$(obj)u-boot.bin: $(obj)u-boot
Here, $(obj) is empty for in-tree build, whereas it points
to the output directory for out-of-tree build.
And our old build system changes the current working directory
with "make -C <sub-dir>" syntax when descending into the
sub-directories.
On the other hand, Kbuild uses a different idea
to handle out-of-tree build and directory descending.
The build process of Kbuild always occurs under the output tree.
When "O=dir/to/store/output/files" is given, the build system
changes the current working directory to that directory and
restarts the make.
Kbuild uses "make -f $(srctree)/scripts/Makefile.build obj=<sub-dir>"
syntax for descending into sub-directories.
(We can write it like "make $(obj)=<sub-dir>" with a shorthand.)
This means the current working directory is always the top
of the output directory.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Tested-by: Gerhard Sittig <gsi@denx.de>
Some editors such as Emacs can highlight source files.
But their parser algorithm is not perfect.
If you use one double-quotation alone, some editor cannot
handle it nicely and mark source lines as a string by mistake.
It is preferable to use two double-quotations as a pair.
Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Now that common code is a bit smarter when it comes to default LDSCRIPT
values, rename the default Blackfin file and drop the Blackfin-specific
config.mk logic.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Rename STANDALONE_LOAD_ADDR into CONFIG_STANDALONE_LOAD_ADDR
and allow that the architecture-specific default value gets
overwritten by defining the value in the board header file.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
Cc: Daniel Hellstrom <daniel@gaisler.com>
Cc: Tsi Chung Liew <tsi-chung.liew@freescale.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
We don't want/use this value for Blackfin boards, so punt it and have the
common code error out when people try to use it.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
commit 8aba9dceeb
Divides variable of linker flags to LDFLAGS-u-boot and LDFLAGS
breaks the usage of --gc-section to build nand_spl. We still need linker option
--gc-section for every uboot image, not only the main one. LDFLAGS_FINAL passes
the --gc-sections to each uboot image.
To get the proper linker flags, we use LDFLAGS and LDFLAGS_FINAL to replace
PLATFORM_LDFLAGS in the Makefile of each nand_spl board.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>
Linker needs to use the proper endian/bfd flags even when doing partial linking.
LDFLAGS_u-boot sets linker option which is called it when U-boot is built
(u-boot final).
LDFLAGS sets necessary option by partial linking (use in cmd_link_o_target).
CC: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Now that the common code takes care of stripping away quotes and such
from numeric options, we no longer need to do so ourselves. So drop
the custom code we have in the Blackfin config.mk.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Since we're no longer extracting the env from the target ELF file (since
upstream wouldn't take that change), we're back to the problem of cpu
defines not properly propagating to the env setup stage. So the embedded
env built by the host compiler doesn't match the one that is linked into
the u-boot env.
Reported-by: Vivi Li <vivi.li@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
The CONFIG_BFIN_CPU option is largely used in the build system, so move
it out of the board config.h and into the board config.mk. It'd be nice
to keep everything in the config.h, but the patch to extract that value
early was rejected.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Also move lib_$ARCH/config.mk to arch/$ARCH/config.mk
This change is intended to clean up the top-level directory structure
and more closely mimic Linux's directory organization.
Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
