0 . 准备工作与说明
0.1 准备工作
请先下载以下文件,里面有文档:
https://gitee.com/weidongshan/openharmony_for_imx6ull/repository/archive/master.zip
参考GIT中的文档,安装好虚拟机,从GIT总下载Liteos-a源码,打上IMX6ULL的补丁。
0.2 说明
1. Makefile编译系统分析
1.1 变量
1. LITEOSTOPDIR // kernel/liteos_a
2. LITEOSTHIRDPARTY // third_party
3. LITEOS_MK_PATH // kernel/liteos_a/tools/build/mk
4. MK_PATH = $(LITEOSTOPDIR)/tools/build/mk // kernel/liteos_a/tools/build/mk
1.2 包含的文件
Makefile
-include $(LITEOSTOPDIR)/tools/build/config.mk
-include $(LITEOSTOPDIR)/tools/build/mk/los_config.mk
-include $(LITEOSTOPDIR)/.config
include $(LITEOSTOPDIR)/arch/cpu.mk
-include $(LITEOSTOPDIR)/arch/arm/arm.mk
include $(LITEOSTOPDIR)/platform/bsp.mk
include $(LITEOSTOPDIR)/../../vendor/nxp/imx6ull/imx6ull.mk
include $(LITEOSTOPDIR)/../../drivers/hdf/lite/hdf_lite.mk
include $(LITEOSTOPDIR)/../../vendor/nxp/hdf/hdf_vendor.mk
-include $(LITEOSTOPDIR)/3rdParty/3rdParty.mk
-include $(LITEOS_MK_PATH)/liteos_tables_ldflags.mk
-include $(LITEOS_MK_PATH)/dynload.mk
1.3 把Makefile全部展开
得到了一个Makefile_all.txt,
分析Makefile_all.txt,就可以知道编译过程。
1.4 分析在kernel/liteos_a下执行make的过程
1.4.1 第1个目标
all: $(OUT) $(BUILD) $(LITEOS_TARGET) $(APPS)
1.4.2 目标:OUT
OUT目标:
# .config文件中, LOSCFG_PLATFORM="imx6ull"
OUT= $(LITEOSTOPDIR)/out/$(LITEOS_PLATFORM)
$(OUT): $(LITEOS_MENUCONFIG_H)
$(HIDE)mkdir -p $(OUT)/lib
$(HIDE)$(CC) -I$(LITEOS_PLATFORM_BASE)/include -I$(BOARD_INCLUDE_DIR) \
-E $(LITEOS_PLATFORM_BASE)/board.ld.S \
-o $(LITEOS_PLATFORM_BASE)/board.ld -P
OUT的依赖:LITEOS_MENUCONFIG_H
LITEOS_MENUCONFIG_H = $(LITEOSTOPDIR)/include/generated/autoconf.h
KCONFIG_FILE_PATH = $(LITEOSTOPDIR)/Kconfig
$(LITEOS_MENUCONFIG_H):
ifneq ($(LITEOS_PLATFORM_MENUCONFIG_H), $(wildcard $(LITEOS_PLATFORM_MENUCONFIG_H)))
$(HIDE)$(MAKE) genconfig
endif
genconfig:$(MENUCONFIG_PATH)/conf
$(HIDE)mkdir -p include/config include/generated
$
-mv -f $(LITEOS_MENUCONFIG_H) $(LITEOS_PLATFORM_MENUCONFIG_H)
1.4.3 目标:BUILD
创建目录 kernel/liteos_a/imx6ull/obj
OUT= $(LITEOSTOPDIR)/out/$(LITEOS_PLATFORM)
BUILD = $(OUT)/obj
$(BUILD):
$(HIDE)mkdir -p $(BUILD)
1.4.4 目标:LITEOS_TARGET
LITEOS_TARGET = liteos
$(LITEOS_TARGET): $(__LIBS)
$(HIDE)touch $(LOSCFG_ENTRY_SRC)
$(HIDE)fordirin$(LITEOS_SUBDIRS); \
do $(MAKE) -C $$dir all|| exit 1; \
done
$(LD) $(LITEOS_LDFLAGS) $(LITEOS_TABLES_LDFLAGS) $(LITEOS_DYNLDFLAGS) -Map=$(OUT)/[email protected] -o $(OUT)/$@--start-group $(LITEOS_LIBDEP) --end-group
# $(SIZE) -t--common $(OUT)/lib/*.a >$(OUT)/[email protected]
$(OBJCOPY) -O binary$(OUT)/$@ $(LITEOS_TARGET_DIR)/[email protected]
$(OBJDUMP) -t $(OUT)/$@ |sort >$(OUT)/[email protected]
$(OBJDUMP) -d $(OUT)/$@ >$(OUT)/[email protected]
# $(NM) -S --size-sort $(OUT)/$@ >$(OUT)/[email protected]
目标:__LIBS
# 没做什么事
__LIBS = libs
$(__LIBS): $(OUT) $(CXX_INCLUDE)
命令:$(HIDE)touch $(LOSCFG_ENTRY_SRC)
每次都要编译los_config.c,touch一下
LOSCFG_ENTRY_SRC = $(LITEOSTOPDIR)/kernel/common/los_config.c
命令:进入每个LITEOS_SUBDIRS,执行make,后面重点讲解各个子目录的编译
# LIB_SUBDIRS 等于一系列的目录
LIB_SUBDIRS :=
LIB_SUBDIRS += arch/arm/$(LITEOS_ARCH_ARM) # 就是arch/arm/arm
LIB_SUBDIRS += $(PLATFORM_BSP_HISI_BASE)
LIB_SUBDIRS += $(LITEOSTOPDIR)/kernel/common
LIB_SUBDIRS += kernel/base
LIB_SUBDIRS += $(IMX6ULL_BASE_DIR)/board
LIB_SUBDIRS += $(IMX6ULL_BASE_DIR)/driver/mtd/common
LIB_SUBDIRS += $(IMX6ULL_BASE_DIR)/driver/mtd/spi_nor
LIB_SUBDIRS += $(IMX6ULL_BASE_DIR)/driver/imx6ull-fb
LIB_SUBDIRS += $(IMX6ULL_BASE_DIR)/driver/imx6ull-uart
LIB_SUBDIRS += kernel/extended/cpup
LIB_SUBDIRS += lib/libc
LIB_SUBDIRS += lib/libsec
LIB_SUBDIRS += lib/libscrew
LIB_SUBDIRS += fs/fat
LIB_SUBDIRS += fs/jffs2
LITEOS_SUBDIRS = $(LIB_SUBDIRS)
$(HIDE)fordirin$(LITEOS_SUBDIRS); \
do $(MAKE) -C $$dir all|| exit 1; \
done
链接及各类处理
$(LD) $(LITEOS_LDFLAGS) $(LITEOS_TABLES_LDFLAGS) $(LITEOS_DYNLDFLAGS) -Map=$(OUT)/[email protected] -o $(OUT)/$@--start-group $(LITEOS_LIBDEP) --end-group
# $(SIZE) -t--common $(OUT)/lib/*.a >$(OUT)/[email protected]
$(OBJCOPY) -O binary$(OUT)/$@ $(LITEOS_TARGET_DIR)/[email protected]
$(OBJDUMP) -t $(OUT)/$@ |sort >$(OUT)/[email protected]
$(OBJDUMP) -d $(OUT)/$@ >$(OUT)/[email protected]
# $(NM) -S --size-sort $(OUT)/$@ >$(OUT)/[email protected]
1.4.5 怎么编译各个子目录
第1行包含config.mk
这是包含一些预先定义的变量,比如默认的编译选项等。
定义了LOCAL_SRCS
等于一系列C文件,这就是要编译的源文件。
定义了LOCAL_INCLUDE
这是头文件的目录
定义了LOCAL_FLAGS
这是编译选项
定义了MODULE_NAME
一般等于当前目录的名字,比如fat,以后就编译得到libfat.a
怎么编译?看最后一行
include $(MODULE)
MODULE就是:
MODULE = $(MK_PATH)/module.mk # kernel/liteos_a/tools/build/mk/module.mk
分析module.mk:
# 找到第1个目标
all: $(LIB)
# LIB是什么, 如果没定义LOCAL_SO,LIB就是 lib$(MODULE_NAME).a, 比如 libfat.a
ifeq ($(LOCAL_SO), y)
LIBSO := $(OUT)/lib/lib$(MODULE_NAME).so
LIBA := $(OUT)/lib/lib$(MODULE_NAME).a
else
LIBSO :=
LIBA := $(OUT)/lib/lib$(MODULE_NAME).a
endif
LIB := $(LIBA) $(LIBSO)
# 怎么编译 LIBA ? 看下图
【编辑推荐】
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