Makefile 笔记

最近在写Makefile 中途出了一些错误和Makefile的一些用法， 正好在这里记下, 语言功底太差， 直接上出错的代码。

出自 https://github.com/bedreamer/fdos/

绿色表示解决问题要处理的地方
红色表示出错的地方
蓝色部分为出错的地方及解决方案。
描述：
https://github.com/bedreamer/fdos/blob/master/Makfile
# Makefile for fdos.
# < cuplision@163.com>
# 通过include来包含其他的Makefile相关文件
# config file, auto been generated
include .config
# define exported values.
include .exports

KERNELFILE=KFOOL
# RELEASE=0 release
# RELEASE=1 debug
# RELEASE=2 demon
RELEASE=2
VMDIR=/home/cup/VBoxVMs/fdos/fdos.vbox
CC=gcc
AS=nasm
LD=ld
AR=ar
MAKE=make
MAKEPARAM=--no-print-directory
#MAKEPARAM=
OMIT=-
PWD=pwd
WORKDIR=$(shell pwd)
IMGFILE=$(WORKDIR)/floppy.img
Q=@
#Q=
CFLAGS=-D_KERNEL_ -D_VERSION_=$(RELEASE) -I$(WORKDIR)/$(ARCH)\
        -I$(WORKDIR)/include -Wall -ffreestanding \
       -fno-builtin -fno-builtin-function -fno-stack-protector\
         -z nodefaultlib -I$(WORKDIR)/include/drivers -c 
CCFLAGS+=-D_ARCH_$(ARCH)_
CBUILDIN=-D_BUILDIN_ $(CFLAGS)
# used for some directory.
CPFLAGS=
ASFLAGS+=-I $(WORKDIR)/include/ -I $(WORKDIR)/$(ARCH) -f elf
BINASFLAGS=
# build-in objects.
y-objs=
yobjs-list=$(WORKDIR)/.yobjs
# module objects.
m-objs=
mobjs-list=$(WORKDIR)/.mobjs
# separate objects.
s-objs=
sobjs-list=$(WORKDIR)/.sobjs
# binary objects.
b-objs=
PHONY+=y-objs m-objs s-objs b-objs
EXPORTS+=KERNELFILE VERSION CC AS LD AR MAKE MAKEPARAM OMIT \
        PWD ARCH WORKDIR IMGFILE Q CFLAGS CCFLAGS CMODULE \
        CBUILDIN ASFLAGS BINASFLAGS CPFLAGS yobjs-list mobjs-list\
         sobjs-list
SEP-DIRS=kernel lib $(ARCH)
# must be the last one.
LAST-DIR=boot
SUB-DIRS=drivers fs

all: _all
PHONY+=all _all
# FIXME: maybe there is a better way to refresh objects-list files.
_all:
$(Q)echo ''> $(yobjs-list);echo ''> $(mobjs-list);echo ''> $(sobjs-list);
$(Q)for d in $(SEP-DIRS) $(SUB-DIRS) $(LAST-DIR); do\
  $(MAKE) $(MAKEPARAM) -C $$d all;\
     done
PHONY+=all
clean:
cmd1: $(Q)$(OMIT)rm $(WORKDIR)/$(KERNELFILE) 2>/dev/null;
cmd2: $(Q)$(OMIT)for d in $(SEP-DIRS) $(SUB-DIRS) $(LAST-DIR); do\
cmd3:   $(MAKE) $(MAKEPARAM) -C $$d clean 2>/dev/null;\
     done
# 这里出错了执行make clean时无法执行上面cmd2, cmd3, 后来发现是cmd1执行失败了， 导致make退出，
# 这里的解决办法是忽略执行命令行时出现的错误， 可以通过在命令行前加'-'来实现， 在这里通过$(OMIT) 实现。

PHONY+=clean

image:

            $(Q)$(MAKE) $(MAKEPARAM) -C boot boot-img

PHONY+=image

debug:

           $(Q)$(OMIT)virtualbox --startvm $(VMDIR) --dbg &

           $(Q)$(OMIT)echo "Debuger starting....."

PHONY+=debug

DOEXPORTS=$(EXPORTS)

export $(EXPORTS) DOEXPORTS

# 导出两次环境变量是为了解决子目录中存在递归式Makefile的问题。
.PHONY: $(PHONY)

https://github.com/bedreamer/fdos/blob/master/Rule.make
# if you need a sub-dir Makefile, you can define
# `sub-didrs:=$(somedirs)` in your Makefile before include this rule file.
# define `m-objs:=$(module)` to build a kernel module, depends on m-deps
# so you need define the other value named`m-deps:=$(some-objects` also.
include $(WORKDIR)/.config
# 如果子目录中存在需要使用Makefile, 则在Makfile中定义变量sub-dirs并将需要递归执行make操作的目录初始化至sub-dirs
# this is for sub-dirs Make rule.
ifdef sub-dirs
suball:=sub_all
subclean:=sub_clean

sub_all:
$(Q)$(OMIT)for d in $(sub-dirs); do $(MAKE) $(MAKEPARAM) -C $$d all;done;
PHONY+=sub_all

sub_clean:
$(Q)$(OMIT)for d in $(sub-dirs); do $(MAKE) $(MAKEPARAM) -C $$d clean;done;
PHONY+=sub_clean
endif
# 如果是编译内核模块， 则将该宏定义添加到编译参数中， 其中CPFLAGS为编译的扩展参数。
ifdef m-objs
CPFLAGS+=-D_MODULE_
endif

# for module complire.
$(m-objs) : $(m-deps)

all : $(b-objs) $(s-deps) $(y-deps) $(m-objs) $(suball) $(nothing)
$(Q)$(OMIT)for o in $(y-deps); do PWD=`pwd`; echo $$PWD/$$o >> $(yobjs-list); done;
$(Q)$(OMIT)for o in $(s-deps); do PWD=`pwd`; echo $$PWD/$$o >> $(sobjs-list); done
PHONY+=all

clean: $(subclean)
$(Q)$(OMIT)echo "    RM        `pwd`/{m-objs m-deps y-deps s-deps}"
$(Q)$(OMIT)rm build-in.a $(m-objs) $(m-deps) $(y-deps) $(s-deps);
PHONY+=clean
# 根据扩展名来实现规则的自动匹配， 可以通过.c文件生成.o文件， 或通过.s 文件生成.o文件, make会自动匹配。
%.o : %.c Makefile
$(Q)echo "    CC        `pwd`/$<"
$(Q)$(CC) $(CFLAGS) $(CCFLAGS) $(CPFLAGS) -o $@ $<
%.o : %.s Makefile
$(Q)echo "    ASM         `pwd`/$<"
$(Q)$(AS) $(ASFLAGS) -o $@ $<
# 生成boot-loader文件时无法生成boot.s和loader.s对应的.bin 文件后来发现把下面一行写成了%.bin : %s Makefile
# 忘记了 '%' 和 's'之间少了 '.'
%.bin : %.s Makefile
    $(Q)echo " ASM [BIN] `pwd`/$<"
    $(Q)$(AS) $(BINASFLAGS) -o $@ $<
# kernel module file is a share libary file.
%.ko : $(m-deps) Makefile
    $(Q)echo " LD [M] $@"
    $(Q)$(LD) --shared $(m-deps) -o $@
    $(Q)echo "`pwd`/$@" >> $(mobjs-list); done
# used for multi level Makefile.
.PHONY:$(PHONY)
# you can export some private value in sub-dir also.
# usage: EXPORT+=SOME-VALUE
export $(EXPORT)
# for sub-dir enviroment.
export $(DOEXPORTS)

https://github.com/bedreamer/fdos/blob/master/fs/Makfile
# 通过y-deps 变量指定当前目录中要生成的目标文件
# 同时可以使用sub-dirs 变量指定要递归执行make 的功能。
y-deps:=open.o read.o write.o ioctl.o close.o iname.o mount.o umount.o
sub-dirs:=fat ext ntfs proc rootfs tmpfs
include $(WORKDIR)/Rule.make


https://github.com/bedreamer/fdos/blob/master/drivers/ide/Makfile
$(IDE-CONFIG)-objs:=ide.ko
$(IDE-CONFIG)-deps:=pci.o pciclass.o
# 可以在任意目录中通过sub-dirs来实现递归make
sub-dirs:=i3600 i3800 i3900 i4000 i4100 i4200
include $(WORKDIR)/Rule.make

https://github.com/bedreamer/fdos/blob/master/fs/ext/Makefile
# 通过make中的函数自动生成需要的变量， SRC 变量会被初始化为当前目录下所有扩展名为 .c 的文件名。
# 然后通过patsubst函数.c 替换为 .o
SRCS=$(wildcard *.c)
OBJS=$(patsubst %.c,%.o,$(SRCS))
$(EXTFS-CONFIG)-objs:=ext.ko
$(EXTFS-CONFIG)-deps:=$(OBJS)
include $(WORKDIR)/Rule.make