U-Boot Makefiles contain a number of tests for compiler features etc.
which so far are executed again and again. On some architectures
(especially ARM) this results in a large number of calls to gcc.
This patch makes sure to run such tests only once, thus largely
reducing the number of "execve" system calls.
Example: number of "execve" system calls for building the "P2020DS"
(Power Architecture) and "qong" (ARM) boards, measured as:
-> strace -f -e trace=execve -o /tmp/foo ./MAKEALL <board>
-> grep execve /tmp/foo | wc -l
Before: After: Reduction:
==================================
P2020DS 20555 15205 -26%
qong 31692 14490 -54%
As a result, built times are significantly reduced, typically by
30...50%.
Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Albert Aribaud <albert.aribaud@free.fr>
cc: Graeme Russ <graeme.russ@gmail.com>
cc: Mike Frysinger <vapier@gentoo.org>
Tested-by: Graeme Russ <graeme.russ@gmail.com>
Tested-by: Matthias Weisser <weisserm@arcor.de>
Tested-by: Sanjeev Premi <premi@ti.com>
Tested-by: Simon Glass <sjg@chromium.org>
Tested-by: Macpaul Lin <macpaul@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Currently, some linker scripts are found by common code in config.mk.
Some are found using CONFIG_SYS_LDSCRIPT, but the code for that is
sometimes in arch config.mk and sometimes in board config.mk. Some
are found using an arch-specific rule for looking in CPUDIR, etc.
Further, the powerpc config.mk rule relied on CONFIG_NAND_SPL
when it really wanted CONFIG_NAND_U_BOOT -- which covered up the fact
that not all NAND_U_BOOT builds actually wanted CPUDIR/u-boot-nand.lds.
Replace all of this -- except for a handful of boards that are actually
selecting a linker script in a unique way -- with centralized ldscript
finding.
If board code specifies LDSCRIPT, that will be used.
Otherwise, if CONFIG_SYS_LDSCRIPT is specified, that will be used.
If neither of these are specified, then the central config.mk will
check for the existence of the following, in order:
$(TOPDIR)/board/$(BOARDDIR)/u-boot-nand.lds (only if CONFIG_NAND_U_BOOT)
$(TOPDIR)/$(CPUDIR)/u-boot-nand.lds (only if CONFIG_NAND_U_BOOT)
$(TOPDIR)/board/$(BOARDDIR)/u-boot.lds
$(TOPDIR)/$(CPUDIR)/u-boot.lds
Some boards (sc3, cm5200, munices) provided their own u-boot.lds that
were dead code, because they were overridden by a CPUDIR u-boot.lds under
the old powerpc rules. These boards' own u-boot.lds have bitrotted and
no longer work -- these lds files have been removed.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Tested-by: Graeme Russ <graeme.russ@gmail.com>
