ESP8266 SDK makefile分析

桃扇骨 2022-04-13 06:12 300阅读 0赞

转载自[https://blog.csdn.net/u012163234/article/details/79495897][https_blog.csdn.net_u012163234_article_details_79495897]

主要内容  
本章我们来分析SDK中的Makefile，同时学习如何创建自己的源码文件夹。

预备知识  
一份代码工程编译成二进制可执行文件，需要经过四个步骤：预处理、编译、汇编和链接。

进行编译需要有编译器，Linux环境下使用的是gcc，而对应的，ESP8266使用的编译器是xtensa-lx106-elf-gcc。在后面分析Makefile中，我们就会看到该编译器。

下面是其他一些工具的含义：

ar：用于建立或修改备存文件，或是从备存文件中抽取文件  
nm：用来列出目标文件的符号清单  
objcopy：将目标文件的一部分或者全部内容拷贝到另外一个目标文件中，或者实现目标文件的格式转换  
objdump：查看目标文件或者可执行的目标文件的构成  
Makefile分析  
首先我们来看看ESP8266 SDK的目录结构以及Makefile：

│  License  
│  Makefile \# 主目录下的Makefile  
├─app/  
│   │  Makefile  
│   ├─ driver  
│   └─ user  
│       └─ Makefile  
├─bin  
├─documents  
├─driver\_lib    
├─examples  
├─lib  
├─include      
├─ld  
└─tools  
  
由此可见，我们至少要分析三个Makefile：

主目录下的Makefile  
app目录下的Makefile  
app/user/的Makefile  
主目录下的Makefile  
下面我们来hack一下主目录下的Makefile，详细解释请看注释：

\#  copyright (c) 2010 Espressif System  
\#  
ifndef PDIR

endif

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 编译工具配置  
\# ESP8266 主要使用的编译器是 xtensa-lx106-elf-gcc

ifeq ($(COMPILE), gcc)  
    AR = xtensa-lx106-elf-ar  
    CC = xtensa-lx106-elf-gcc  
    NM = xtensa-lx106-elf-nm  
    CPP = xtensa-lx106-elf-cpp  
    OBJCOPY = xtensa-lx106-elf-objcopy  
    OBJDUMP = xtensa-lx106-elf-objdump  
else  
    AR = xt-ar  
    CC = xt-xcc  
    NM = xt-nm  
    CPP = xt-cpp  
    OBJCOPY = xt-objcopy  
    OBJDUMP = xt-objdump  
endif

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 参数默认配置

\# =none - 不使用boot  
\# =old - 使用老版本的boot\_v1.1+  
\# =new - 使用新版本的boot\_v1.2+  
BOOT?=none

\# =0 - 不使用远程升级FOTA  
\# =1 - 使用FOTA，生成user1.<flash\_map>.<BOOT>.bin  
\# =2 - 使用FOTA，生成user2.<flash\_map>.<BOOT>.bin  
APP?=0

\# SPI速率和模式，一般不用改动  
SPI\_SPEED?=40  
SPI\_MODE?=QIO

\# SPI\_SIZE\_MAP flash映射方式  
\# 4MB Flash使用 SPI\_SIZE\_MAP?=4  
SPI\_SIZE\_MAP?=4

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

ifeq ($(BOOT), new)  
    boot = new  
else  
    ifeq ($(BOOT), old)  
        boot = old  
    else  
        boot = none  
    endif  
endif

ifeq ($(APP), 1)  
    app = 1  
else  
    ifeq ($(APP), 2)  
        app = 2  
    else  
        app = 0  
    endif  
endif

ifeq ($(SPI\_SPEED), 26.7)  
    freqdiv = 1  
else  
    ifeq ($(SPI\_SPEED), 20)  
        freqdiv = 2  
    else  
        ifeq ($(SPI\_SPEED), 80)  
            freqdiv = 15  
        else  
            freqdiv = 0  
        endif  
    endif  
endif

ifeq ($(SPI\_MODE), QOUT)  
    mode = 1  
else  
    ifeq ($(SPI\_MODE), DIO)  
        mode = 2  
    else  
        ifeq ($(SPI\_MODE), DOUT)  
            mode = 3  
        else  
            mode = 0  
        endif  
    endif  
endif

addr = 0x01000

ifeq ($(SPI\_SIZE\_MAP), 1)  
  size\_map = 1  
  flash = 256  
else  
  ifeq ($(SPI\_SIZE\_MAP), 2)  
    size\_map = 2  
    flash = 1024  
    ifeq ($(app), 2)  
      addr = 0x81000  
    endif  
  else  
    ifeq ($(SPI\_SIZE\_MAP), 3)  
      size\_map = 3  
      flash = 2048  
      ifeq ($(app), 2)  
        addr = 0x81000  
      endif  
    else  
      ifeq ($(SPI\_SIZE\_MAP), 4)  
        size\_map = 4  
        flash = 4096  
        ifeq ($(app), 2)  
          addr = 0x81000  
        endif  
      else  
        ifeq ($(SPI\_SIZE\_MAP), 5)  
          size\_map = 5  
          flash = 2048  
          ifeq ($(app), 2)  
            addr = 0x101000  
          endif  
        else  
          ifeq ($(SPI\_SIZE\_MAP), 6)  
            size\_map = 6  
            flash = 4096  
            ifeq ($(app), 2)  
              addr = 0x101000  
            endif  
          else  
            size\_map = 0  
            flash = 512  
            ifeq ($(app), 2)  
              addr = 0x41000  
            endif  
          endif  
        endif  
      endif  
    endif  
  endif  
endif

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 选择链接工具  
\# 这里选择了主目录下的 ld/eagle.app.v6.ld  
LD\_FILE = $(LDDIR)/eagle.app.v6.ld

\# 如果boot!=none，才进入这里  
ifneq ($(boot), none)  
ifneq ($(app),0)  
    ifeq ($(size\_map), 6)  
      LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).2048.ld  
    else  
      ifeq ($(size\_map), 5)  
        LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).2048.ld  
      else  
        ifeq ($(size\_map), 4)  
          LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).1024.app$(app).ld  
        else  
          ifeq ($(size\_map), 3)  
            LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).1024.app$(app).ld  
          else  
            ifeq ($(size\_map), 2)  
              LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).1024.app$(app).ld  
            else  
              ifeq ($(size\_map), 0)  
                LD\_FILE = $(LDDIR)/eagle.app.v6.$(boot).512.app$(app).ld  
              endif  
            endif  
          endif  
        endif  
      endif  
    endif  
    BIN\_NAME = user$(app).$(flash).$(boot).$(size\_map)  
endif  
else  
    app = 0  
endif

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

CSRCS ?= $(wildcard \*.c)  
ASRCs ?= $(wildcard \*.s)  
ASRCS ?= $(wildcard \*.S)  
SUBDIRS ?= $(patsubst %/,%,$(dir $(wildcard \*/Makefile)))

ODIR := .output  
OBJODIR := $(ODIR)/$(TARGET)/$(FLAVOR)/obj

\# 设置 OBJS 变量  
OBJS := $(CSRCS:%.c=$(OBJODIR)/%.o) \\  
        $(ASRCs:%.s=$(OBJODIR)/%.o) \\  
        $(ASRCS:%.S=$(OBJODIR)/%.o)

\# 设置 DEPS 变量  
DEPS := $(CSRCS:%.c=$(OBJODIR)/%.d) \\  
        $(ASRCs:%.s=$(OBJODIR)/%.d) \\  
        $(ASRCS:%.S=$(OBJODIR)/%.d)

\# 设置 LIBODIR 库文件夹  
LIBODIR := $(ODIR)/$(TARGET)/$(FLAVOR)/lib  
OLIBS := $(GEN\_LIBS:%=$(LIBODIR)/%)

IMAGEODIR := $(ODIR)/$(TARGET)/$(FLAVOR)/image  
OIMAGES := $(GEN\_IMAGES:%=$(IMAGEODIR)/%)

\# 设置 BINODIR 二进制文件夹  
BINODIR := $(ODIR)/$(TARGET)/$(FLAVOR)/bin  
OBINS := $(GEN\_BINS:%=$(BINODIR)/%)

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
CCFLAGS +=          \\  
    -g                      \\  
    -Wpointer-arith         \\  
    -Wundef                 \\  
    -Werror                 \\  
    -Wl,-EL                 \\  
    -fno-inline-functions   \\  
    -nostdlib               \\  
    -mlongcalls             \\  
    -mtext-section-literals \\  
    -ffunction-sections     \\  
    -fdata-sections         \\  
    -fno-builtin-printf  
\#   -Wall

CFLAGS = $(CCFLAGS) $(DEFINES) $(EXTRA\_CCFLAGS) $(INCLUDES)  
DFLAGS = $(CCFLAGS) $(DDEFINES) $(EXTRA\_CCFLAGS) $(INCLUDES)

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Functions  
\#

define ShortcutRule  
$(1): .subdirs $(2)/$(1)  
endef

define MakeLibrary  
DEP\_LIBS\_$(1) = $$(foreach lib,$$(filter %.a,$$(COMPONENTS\_$(1))),$$(dir $$(lib))$$(LIBODIR)/$$(notdir $$(lib)))  
DEP\_OBJS\_$(1) = $$(foreach obj,$$(filter %.o,$$(COMPONENTS\_$(1))),$$(dir $$(obj))$$(OBJODIR)/$$(notdir $$(obj)))  
$$(LIBODIR)/$(1).a: $$(OBJS) $$(DEP\_OBJS\_$(1)) $$(DEP\_LIBS\_$(1)) $$(DEPENDS\_$(1))  
    @mkdir -p $$(LIBODIR)  
    $$(if $$(filter %.a,$$?),mkdir -p $$(EXTRACT\_DIR)\_$(1))  
    $$(if $$(filter %.a,$$?),cd $$(EXTRACT\_DIR)\_$(1); $$(foreach lib,$$(filter %.a,$$?),$$(AR) xo $$(UP\_EXTRACT\_DIR)/$$(lib);))  
    $$(AR) ru $$@ $$(filter %.o,$$?) $$(if $$(filter %.a,$$?),$$(EXTRACT\_DIR)\_$(1)/\*.o)  
    $$(if $$(filter %.a,$$?),$$(RM) -r $$(EXTRACT\_DIR)\_$(1))  
endef

define MakeImage  
DEP\_LIBS\_$(1) = $$(foreach lib,$$(filter %.a,$$(COMPONENTS\_$(1))),$$(dir $$(lib))$$(LIBODIR)/$$(notdir $$(lib)))  
DEP\_OBJS\_$(1) = $$(foreach obj,$$(filter %.o,$$(COMPONENTS\_$(1))),$$(dir $$(obj))$$(OBJODIR)/$$(notdir $$(obj)))  
$$(IMAGEODIR)/$(1).out: $$(OBJS) $$(DEP\_OBJS\_$(1)) $$(DEP\_LIBS\_$(1)) $$(DEPENDS\_$(1))  
    @mkdir -p $$(IMAGEODIR)  
    $$(CC) $$(LDFLAGS) $$(if $$(LINKFLAGS\_$(1)),$$(LINKFLAGS\_$(1)),$$(LINKFLAGS\_DEFAULT) $$(OBJS) $$(DEP\_OBJS\_$(1)) $$(DEP\_LIBS\_$(1))) -o $$@   
endef

$(BINODIR)/%.bin: $(IMAGEODIR)/%.out  
    @mkdir -p $(BINODIR)

ifeq ($(APP), 0)  
    @$(RM) -r ../bin/eagle.S ../bin/eagle.dump  
    @$(OBJDUMP) -x -s $< > ../bin/eagle.dump  
    @$(OBJDUMP) -S $< > ../bin/eagle.S  
else  
    mkdir -p ../bin/upgrade  
    @$(RM) -r ../bin/upgrade/$(BIN\_NAME).S ../bin/upgrade/$(BIN\_NAME).dump  
    @$(OBJDUMP) -x -s $< > ../bin/upgrade/$(BIN\_NAME).dump  
    @$(OBJDUMP) -S $< > ../bin/upgrade/$(BIN\_NAME).S  
endif

@$(OBJCOPY) --only-section .text -O binary $< eagle.app.v6.text.bin  
    @$(OBJCOPY) --only-section .data -O binary $< eagle.app.v6.data.bin  
    @$(OBJCOPY) --only-section .rodata -O binary $< eagle.app.v6.rodata.bin  
    @$(OBJCOPY) --only-section .irom0.text -O binary $< eagle.app.v6.irom0text.bin

@echo ""  
    @echo "!!!"

\# 默认是 app==0  
\# 下面是输出打印信息  
ifeq ($(app), 0)  
    @python ../tools/gen\_appbin.py $< 0 $(mode) $(freqdiv) $(size\_map) $(app)  
    @mv eagle.app.flash.bin ../bin/eagle.flash.bin  
    @mv eagle.app.v6.irom0text.bin ../bin/eagle.irom0text.bin  
    @rm eagle.app.v6.\*  
    @echo "No boot needed."  
    @echo "Generate eagle.flash.bin and eagle.irom0text.bin successully in folder bin."  
    @echo "eagle.flash.bin-------->0x00000"  
    @echo "eagle.irom0text.bin---->0x10000"  
else  
    ifneq ($(boot), new)  
        @python ../tools/gen\_appbin.py $< 1 $(mode) $(freqdiv) $(size\_map) $(app)  
        @echo "Support boot\_v1.1 and +"  
    else  
        @python ../tools/gen\_appbin.py $< 2 $(mode) $(freqdiv) $(size\_map) $(app)

ifeq ($(size\_map), 6)  
        @echo "Support boot\_v1.4 and +"  
        else  
            ifeq ($(size\_map), 5)  
        @echo "Support boot\_v1.4 and +"  
            else  
        @echo "Support boot\_v1.2 and +"  
            endif  
        endif  
    endif

@mv eagle.app.flash.bin ../bin/upgrade/$(BIN\_NAME).bin  
    @rm eagle.app.v6.\*  
    @echo "Generate $(BIN\_NAME).bin successully in folder bin/upgrade."  
    @echo "boot.bin------------>0x00000"  
    @echo "$(BIN\_NAME).bin--->$(addr)"  
endif

@echo "!!!"

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Rules base  
\# Should be done in top-level makefile only  
\#

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# make all执行的方法  
all:    .subdirs $(OBJS) $(OLIBS) $(OIMAGES) $(OBINS) $(SPECIAL\_MKTARGETS)

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# make clean执行的方法  
clean:  
    $(foreach d, $(SUBDIRS), $(MAKE) -C $(d) clean;)  
    $(RM) -r $(ODIR)/$(TARGET)/$(FLAVOR)

clobber: $(SPECIAL\_CLOBBER)  
    $(foreach d, $(SUBDIRS), $(MAKE) -C $(d) clobber;)  
    $(RM) -r $(ODIR)

.subdirs:  
    @set -e; $(foreach d, $(SUBDIRS), $(MAKE) -C $(d);)

\#.subdirs:  
\#   $(foreach d, $(SUBDIRS), $(MAKE) -C $(d))

ifneq ($(MAKECMDGOALS),clean)  
ifneq ($(MAKECMDGOALS),clobber)  
ifdef DEPS  
sinclude $(DEPS)  
endif  
endif  
endif

\# “$<”表示所有的依赖目标集（所有.c后缀文件），“$@”表示目标集（所有.o后缀文件）

$(OBJODIR)/%.o: %.c  
    @mkdir -p $(OBJODIR);  
    $(CC) $(if $(findstring $<,$(DSRCS)),$(DFLAGS),$(CFLAGS)) $(COPTS\_$(\*F)) -o $@ -c $<

$(OBJODIR)/%.d: %.c  
    @mkdir -p $(OBJODIR);  
    @echo DEPEND: $(CC) -M $(CFLAGS) $<  
    @set -e; rm -f $@; \\  
    $(CC) -M $(CFLAGS) $< > $@.$$$$; \\  
    sed 's,\$$\*\\.o\$\[ :\]\*,$(OBJODIR)/\\1 $@ : ,g' < $@.$$$$ > $@; \\  
    rm -f $@.$$$$

$(OBJODIR)/%.o: %.s  
    @mkdir -p $(OBJODIR);  
    $(CC) $(CFLAGS) -o $@ -c $<

$(OBJODIR)/%.d: %.s  
    @mkdir -p $(OBJODIR); \\  
    set -e; rm -f $@; \\  
    $(CC) -M $(CFLAGS) $< > $@.$$$$; \\  
    sed 's,\$$\*\\.o\$\[ :\]\*,$(OBJODIR)/\\1 $@ : ,g' < $@.$$$$ > $@; \\  
    rm -f $@.$$$$

$(OBJODIR)/%.o: %.S  
    @mkdir -p $(OBJODIR);  
    $(CC) $(CFLAGS) -D\_\_ASSEMBLER\_\_ -o $@ -c $<

$(OBJODIR)/%.d: %.S  
    @mkdir -p $(OBJODIR); \\  
    set -e; rm -f $@; \\  
    $(CC) -M $(CFLAGS) $< > $@.$$$$; \\  
    sed 's,\$$\*\\.o\$\[ :\]\*,$(OBJODIR)/\\1 $@ : ,g' < $@.$$$$ > $@; \\  
    rm -f $@.$$$$

$(foreach lib,$(GEN\_LIBS),$(eval $(call ShortcutRule,$(lib),$(LIBODIR))))

$(foreach image,$(GEN\_IMAGES),$(eval $(call ShortcutRule,$(image),$(IMAGEODIR))))

$(foreach bin,$(GEN\_BINS),$(eval $(call ShortcutRule,$(bin),$(BINODIR))))

$(foreach lib,$(GEN\_LIBS),$(eval $(call MakeLibrary,$(basename $(lib)))))

$(foreach image,$(GEN\_IMAGES),$(eval $(call MakeImage,$(basename $(image)))))

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Recursion Magic - Don't touch this!!  
\#  
\# Each subtree potentially has an include directory  
\#   corresponding to the common APIs applicable to modules  
\#   rooted at that subtree. Accordingly, the INCLUDE PATH  
\#   of a module can only contain the include directories up  
\#   its parent path, and not its siblings  
\#  
\# Required for each makefile to inherit from the parent  
\#

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 设置头文件路径  
\# 把主目录下的 include头文件包含进来  
INCLUDES := $(INCLUDES) -I $(PDIR)include -I $(PDIR)include/$(TARGET) -I $(PDIR)driver\_lib/include  
PDIR := ../$(PDIR)  
sinclude $(PDIR)Makefile  
app下的Makefile  
下面我们就来hack一下app/Makefile

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Required variables for each makefile  
\# Discard this section from all parent makefiles  
\# Expected variables (with automatic defaults):  
\#   CSRCS (all "C" files in the dir)  
\#   SUBDIRS (all subdirs with a Makefile)  
\#   GEN\_LIBS - list of libs to be generated ()  
\#   GEN\_IMAGES - list of object file images to be generated ()  
\#   GEN\_BINS - list of binaries to be generated ()  
\#   COMPONENTS\_xxx - a list of libs/objs in the form  
\#     subdir/lib to be extracted and rolled up into  
\#     a generated lib/image xxx.a ()  
\#

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#

TARGET = eagle  
\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 选择debug工程还是release  
\#FLAVOR = release  
FLAVOR = debug

\#EXTRA\_CCFLAGS += -u

ifndef PDIR \# \{  
GEN\_IMAGES= eagle.app.v6.out  
GEN\_BINS= eagle.app.v6.bin  
SPECIAL\_MKTARGETS=$(APP\_MKTARGETS)

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 子目录，如果你在app里新建了一个源文件目录，需要添加到这里  
\# 否则不会编译未添加的目录的源文件！  
SUBDIRS=    \\  
    user    \\  
    driver

\# 比如添加了一个 network 文件夹，则：  
\#SUBDIRS=    \\  
\#   user    \\  
\#   driver  \\  
\#   network

endif \# \} PDIR

APPDIR = .  
LDDIR = ../ld

CCFLAGS += -Os

TARGET\_LDFLAGS =    \\  
    -nostdlib       \\  
    -Wl,-EL         \\  
    --longcalls     \\  
    --text-section-literals

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 根据 FLAVOR 变量选择优化等级  
\# -O0不优化，-O2中级优化  
ifeq ($(FLAVOR),debug)  
    TARGET\_LDFLAGS += -g -O2  
endif

ifeq ($(FLAVOR),release)  
    TARGET\_LDFLAGS += -g -O0  
endif

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 添加静态链接库，对应前面 SUBDIRS 变量设置的目录  
\# 每一个文件夹里的源代码先编译成对应的静态库，然后在进行链接  
\# 所以如果添加新的源码文件夹，也需要在这里添加对应的静态库！  
COMPONENTS\_eagle.app.v6 =   \\  
    user/libuser.a          \\  
    driver/libdriver.a

\# 比如添加network：  
\#COMPONENTS\_eagle.app.v6 =   \\  
\#   user/libuser.a          \\  
\#   driver/libdriver.a  \\  
\#   network/libnetwork.a

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 链接参数  
\# 参考lib文件夹里的静态链接库  
\# 比如，如果需要使用smartconfig接口  
\# 只需要添加 -lsmartconfig 即可。  
LINKFLAGS\_eagle.app.v6 =    \\  
    -L../lib                \\  
    -nostdlib               \\  
    -T$(LD\_FILE)            \\  
    -Wl,--no-check-sections \\  
    -Wl,--gc-sections       \\  
    -u call\_user\_start      \\  
    -Wl,-static             \\  
    -Wl,--start-group       \\  
    -lc                     \\  
    -lgcc                   \\  
    -lhal                   \\  
    -lphy                   \\  
    -lpp                    \\  
    -lnet80211              \\  
    -llwip                  \\ \# lwip静态库，可见ESP8266使用的是lwip协议栈  
    -lwpa                   \\  
    -lcrypto                \\  
    -lmain                  \\ \# main静态库  
    -ljson                  \\ \# JSON静态库  
    -lupgrade               \\ \# OTP在线升级相关库  
    -lssl                   \\ \# 安全链接SSL静态库  
    -lpwm                   \\ \# 有关PWM的静态库  
    -lsmartconfig           \\ \# 快速连接smartconfig  
    $(DEP\_LIBS\_eagle.app.v6)\\  
    -Wl,--end-group

DEPENDS\_eagle.app.v6 = \\  
                $(LD\_FILE) \\  
                $(LDDIR)/eagle.rom.addr.v6.ld

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Configuration i.e. compile options etc.  
\# Target specific stuff (defines etc.) goes in here!  
\# Generally values applying to a tree are captured in the  
\#   makefile at its root level - these are then overridden  
\#   for a subtree within the makefile rooted therein  
\#

\#UNIVERSAL\_TARGET\_DEFINES =     \\

\# Other potential configuration flags include:  
\#   -DTXRX\_TXBUF\_DEBUG  
\#   -DTXRX\_RXBUF\_DEBUG  
\#   -DWLAN\_CONFIG\_CCX  
CONFIGURATION\_DEFINES = -DICACHE\_FLASH

DEFINES +=              \\  
    $(UNIVERSAL\_TARGET\_DEFINES)    \\  
    $(CONFIGURATION\_DEFINES)

DDEFINES +=             \\  
    $(UNIVERSAL\_TARGET\_DEFINES)    \\  
    $(CONFIGURATION\_DEFINES)

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# 把当前目录下的 include 文件夹包含进来  
INCLUDES := $(INCLUDES) -I $(PDIR)include

\# 把子目录包含进来  
PDIR := ../$(PDIR)

\# 把子目录下的Makefile加进来  
\# sinclude：以忽略错误的方式执行  
sinclude $(PDIR)Makefile

.PHONY: FORCE  
FORCE:  
app/user/下的Makefile  
由app/Makefile可知，Makefile最后会把子目录下的Makefile加进来，而且好像还添加了user/libuser.a和driver/libdriver.a，但是这些.a文件怎么生成我们还不知道。

所以我们来看下app/user/下的Makefile做了一些什么事情。

\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#\#  
\# Required variables for each makefile  
\# Discard this section from all parent makefiles  
\# Expected variables (with automatic defaults):  
\#   CSRCS (all "C" files in the dir)  
\#   SUBDIRS (all subdirs with a Makefile)  
\#   GEN\_LIBS - list of libs to be generated ()  
\#   GEN\_IMAGES - list of images to be generated ()  
\#   COMPONENTS\_xxx - a list of libs/objs in the form  
\#     subdir/lib to be extracted and rolled up into  
\#     a generated lib/image xxx.a ()  
\#

\# 仔细阅读上面英文即可知道是什么意思了  
\# 下面语句即是生成 libuser.a   
ifndef PDIR  
GEN\_LIBS = libuser.a  
endif

\# 查找头文件时，进入当前文件夹的 include 文件夹进行查找（如果有）  
INCLUDES := $(INCLUDES) -I $(PDIR)include

\# 在当前文件夹的进行查找  
INCLUDES += -I ./

\# 在主目录下的 include/ets/ 文件夹进行查找  
\# （实际上本人都没有找到 include/ets/ 文件夹）  
INCLUDES += -I ../../include/ets

PDIR := ../$(PDIR)  
sinclude $(PDIR)Makefile  
  
如何新添源码文件夹  
在app/目录下新建一个文件夹，比如叫network；  
然后把app/user/Makefile文件拷贝过去，修改下面语句：

ifndef PDIR  
GEN\_LIBS = libuser.a  
endif  
改为：

ifndef PDIR  
GEN\_LIBS = libnetwork.a  
endif  
  
然后编辑app/Makefile，给SUBDIRS变量和COMPONENTS\_eagle.app.v6添加对应的文件名称即可（app/Makefile代码分析小节已经有说明）；  
SUBDIRS=    \\  
    user    \\  
    driver

COMPONENTS\_eagle.app.v6 =   \\  
user/libuser.a          \\  
driver/libdriver.a  
  
添加network：  
SUBDIRS=    \\  
   user    \\  
   driver  \\  
   network

COMPONENTS\_eagle.app.v6 =   \\  
   user/libuser.a          \\  
   driver/libdriver.a  \\  
   network/libnetwork.a  
最后编译的时候，`network`文件夹下的源码即会被编译进来了。

[https_blog.csdn.net_u012163234_article_details_79495897]: https://blog.csdn.net/u012163234/article/details/79495897