AR =gar # GNU 的二進制文件處理程序，用于創建、修改以及從歸檔文件中抽取文件。AS =gas # GNU 的匯編程序。CC =gcc # GNU C 語言編譯器。LD =gld # GNU 的連接程序。# C 編譯程序選項。-Wall 顯示所有的警告信息；-O 優化選項，優化代碼長度和執行時間；# -fstrength-reduce 優化循環執行代碼，排除重復變量；-fomit-frame-pointer 省略保存不必要# 的框架指針；-fcombine-regs 合并寄存器，減少寄存器類的使用；-mstring-insns Linus 自己# 填加的優化選項，以后不再使用；-nostdinc -I../include 不使用默認路徑中的包含文件，而使# 用這里指定目錄中的(../include)。CFLAGS =-Wall -O -fstrength-reduce -fcombine-regs -fomit-frame-pointer \-mstring-insns -nostdinc -I../include# C 前處理選項。-E 只運行C 前處理，對所有指定的C 程序進行預處理并將處理結果輸出到標準輸# 出設備或指定的輸出文件中；-nostdinc -I../include 同前。CPP =gcc -E -nostdinc -I../include# 下面的規則指示make 利用下面的命令將所有的.c 文件編譯生成.s 匯編程序。該規則的命令# 指使gcc 采用CFLAGS 所指定的選項對C 代碼編譯后不進行匯編就停止（-S），從而產生與# 輸入的各個C 文件對應的匯編代碼文件。默認情況下所產生的匯編程序文件名是原C 文件名# 去掉.c 而加上.s 后綴。-o 表示其后是輸出文件的名稱。其中$*.s（或$@）是自動目標變量，# $<代表第一個先決條件，這里即是符合條件*.c 的文件。.c.s:$(CC) $(CFLAGS) \-S -o $*.s $<# 將所有*.c 文件編譯成*.o 目標文件。不進行連接。.c.o:$(CC) $(CFLAGS) \-c -o $*.o $<# 下面規則表示將所有.s 匯編程序文件編譯成.o 目標文件。16 行是實現該操作的具體命令。.s.o:$(AS) -o $*.o $<# 定義目標文件變量OBJS。OBJS= open.o read_write.o inode.o file_table.o buffer.o super.o \block_dev.o char_dev.o file_dev.o stat.o exec.o pipe.o namei.o \bitmap.o fcntl.o ioctl.o truncate.o# 在有了先決條件OBJS 后使用下面的命令連接成目標fs.ofs.o: $(OBJS)$(LD) -r -o fs.o $(OBJS)# 下面的規則用于清理工作。當執行'make clean'時，就會執行26--27 行上的命令，去除所有編譯# 連接生成的文件。'rm'是文件刪除命令，選項-f 含義是忽略不存在的文件，并且不顯示刪除信息。clean:rm -f core *.o *.a tmp_makefor i in *.c;do rm -f `basename $$i .c`.s;done# 下面得目標或規則用于檢查各文件之間的依賴關系。方法如下：# 使用字符串編輯程序sed 對Makefile 文件（這里即是自己）進行處理，輸出為刪除Makefile# 文件中'### Dependencies'行后面的所有行（下面從35 開始的行），并生成tmp_make# 臨時文件（30 行的作用）。然后對fs/目錄下的每一個C 文件執行gcc 預處理操作.# -M 標志告訴預處理程序輸出描述每個目標文件相關性的規則，并且這些規則符合make 語法。# 對于每一個源文件，預處理程序輸出一個make 規則，其結果形式是相應源程序文件的目標# 文件名加上其依賴關系--該源文件中包含的所有頭文件列表。把預處理結果都添加到臨時# 文件tmp_make 中，然后將該臨時文件復制成新的Makefile 文件。dep:sed '/\#\#\# Dependencies/q' < Makefile > tmp_make(for i in *.c;do $(CPP) -M $$i;done) >> tmp_makecp tmp_make Makefile### Dependencies:bitmap.o : bitmap.c ../include/string.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \../include/linux/mm.h ../include/signal.h ../include/linux/kernel.hblock_dev.o : block_dev.c ../include/errno.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \../include/asm/segment.h ../include/asm/system.hbuffer.o : buffer.c ../include/stdarg.h ../include/linux/config.h \../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \../include/sys/types.h ../include/linux/mm.h ../include/signal.h \../include/linux/kernel.h ../include/asm/system.h ../include/asm/io.hchar_dev.o : char_dev.c ../include/errno.h ../include/sys/types.h \../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \../include/asm/segment.h ../include/asm/io.hexec.o : exec.c ../include/errno.h ../include/string.h \../include/sys/stat.h ../include/sys/types.h ../include/a.out.h \../include/linux/fs.h ../include/linux/sched.h ../include/linux/head.h \../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \../include/asm/segment.hfcntl.o : fcntl.c ../include/string.h ../include/errno.h \../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \../include/sys/types.h ../include/linux/mm.h ../include/signal.h \../include/linux/kernel.h ../include/asm/segment.h ../include/fcntl.h \../include/sys/stat.hfile_dev.o : file_dev.c ../include/errno.h ../include/fcntl.h \../include/sys/types.h ../include/linux/sched.h ../include/linux/head.h \../include/linux/fs.h ../include/linux/mm.h ../include/signal.h \../include/linux/kernel.h ../include/asm/segment.hfile_table.o : file_table.c ../include/linux/fs.h ../include/sys/types.hinode.o : inode.c ../include/string.h ../include/sys/stat.h \../include/sys/types.h ../include/linux/sched.h ../include/linux/head.h \../include/linux/fs.h ../include/linux/mm.h ../include/signal.h \../include/linux/kernel.h ../include/asm/system.hioctl.o : ioctl.c ../include/string.h ../include/errno.h \../include/sys/stat.h ../include/sys/types.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/fs.h ../include/linux/mm.h \../include/signal.hnamei.o : namei.c ../include/linux/sched.h ../include/linux/head.h \../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \../include/signal.h ../include/linux/kernel.h ../include/asm/segment.h \../include/string.h ../include/fcntl.h ../include/errno.h \../include/const.h ../include/sys/stat.hopen.o : open.c ../include/string.h ../include/errno.h ../include/fcntl.h \../include/sys/types.h ../include/utime.h ../include/sys/stat.h \../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \../include/linux/mm.h ../include/signal.h ../include/linux/tty.h \../include/termios.h ../include/linux/kernel.h ../include/asm/segment.hpipe.o : pipe.c ../include/signal.h ../include/sys/types.h \../include/linux/sched.h ../include/linux/head.h ../include/linux/fs.h \../include/linux/mm.h ../include/asm/segment.hread_write.o : read_write.c ../include/sys/stat.h ../include/sys/types.h \../include/errno.h ../include/linux/kernel.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/fs.h ../include/linux/mm.h \../include/signal.h ../include/asm/segment.hstat.o : stat.c ../include/errno.h ../include/sys/stat.h \../include/sys/types.h ../include/linux/fs.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/mm.h ../include/signal.h \../include/linux/kernel.h ../include/asm/segment.hsuper.o : super.c ../include/linux/config.h ../include/linux/sched.h \../include/linux/head.h ../include/linux/fs.h ../include/sys/types.h \../include/linux/mm.h ../include/signal.h ../include/linux/kernel.h \../include/asm/system.h ../include/errno.h ../include/sys/stat.htruncate.o : truncate.c ../include/linux/sched.h ../include/linux/head.h \../include/linux/fs.h ../include/sys/types.h ../include/linux/mm.h \100 ../include/signal.h ../include/sys/stat.h