b88561299b
In the current compilation environment, the recursive assignment(=) for compile
flags will be delayed until every file is actually need to be compile.
For example:
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arch/arm/src/Makefile:
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)chip}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)common}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(ARCH_SRCDIR)$(DELIM)$(ARCH_SUBDIR)}
INCLUDES += ${shell $(INCDIR) "$(CC)" $(TOPDIR)$(DELIM)sched}
CPPFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CFLAGS += $(INCLUDES) $(EXTRAFLAGS)
CXXFLAGS += $(INCLUDES) $(EXTRAFLAGS)
AFLAGS += $(INCLUDES) $(EXTRAFLAGS)
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All compilation options will be included recursively,
which will be delayed until the compilation options are actually used:
tools/Config.mk:
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define COMPILE
@echo "CC: $1"
$(Q) $(CC) -c $(CFLAGS) $($(strip $1)_CFLAGS) $1 -o $2
endef
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All compile flags to be reexecuted $(INCDIR) as long as one file needs to be compiled,
but in fact, the compilation options have not changed in the current directory.
So the we recommand to change the syntax of assignment
From
Recursive (=)
To
Simple (:=)
In this way, we can ensure that all compilation options are expanded only once and reducing repeated works.
Signed-off-by: chao.an <anchao@xiaomi.com>
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| .. | ||
| configs | ||
| include | ||
| scripts | ||
| src | ||
| Kconfig | ||
| README.txt | ||
README ====== The Olimex STM32-H407 configuration is based on stm32Fdiscovery and Olimex STM32-H405. The H407 was programmed with ST-LINK/V2 from both Win8.1 and Ubuntu 14.04 This release provides baseline for H407 12MHZ clock in include/board.h nsh - Only basic shell response tested on USART2 nsh_uext - Basic shell response tested on USART6 (UEXT) Development Environment ======================= Either Linux or Cygwin on Windows can be used for the development environment. The source has been built only using the GNU toolchain (see below). Other toolchains will likely cause problems. LEDs ==== The H407 board has 1 Status LED; SDCard ====== Expects to be plugged in else hangs. TODO: Shouldn't hang. SDIO 4bit with pulls/downs on pins. Doesn't have a SD card detect pin. UARTs ===== On the H407 board, ?? all uarts are available for pin mappings USART2 can be used for nsh console like on Discovery board, or you can use USART6 exposed via UEXT connector. Olimex offers MOD-RS232 voltage level converter for the UEXT so it can be attached to computer serial port. STM32-H407-specific Configuration Options ===============================================