XV6操作系统make报错Makefile:192: *** recipe commences before first target. Stop. 的解决方法

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  有很多小伙伴在使用XV6操作系统做相关的实验的时候经常会遇到报错Makefile:192: *** recipe commences before first target. Stop.，然后不知错所，这里提供一个可能报错这个情形，以及解决方法(目前仅用这种方法复习了这个报错，如果有其他情形报错一样，可以把Makefile文件发一份过来看一下)。

这里先上一下我这里复习这种报错时的Makefile文件的内容：

OBJS =   bio.o  console.o  exec.o  file.o  fs.o  ide.o  ioapic.o  kalloc.o  kbd.o  lapic.o  log.o  main.o  mp.o  picirq.o  pipe.o  proc.o  sleeplock.o  spinlock.o  string.o  swtch.o  syscall.o  sysfile.o  sysproc.o  trapasm.o  trap.o  uart.o  vectors.o  vm.o  # Cross-compiling (e.g., on Mac OS X) # TOOLPREFIX = i386-jos-elf # Using native tools (e.g., on X86 Linux) #TOOLPREFIX =  # Try to infer the correct TOOLPREFIX if not set ifndef TOOLPREFIX TOOLPREFIX := $(shell if i386-jos-elf-objdump -i 2>&1 | grep '^elf32-i386$$' >/dev/null 2>&1;   then echo 'i386-jos-elf-';   elif objdump -i 2>&1 | grep 'elf32-i386' >/dev/null 2>&1;   then echo '';   else echo "***" 1>&2;   echo "*** Error: Couldn't find an i386-*-elf version of GCC/binutils." 1>&2;   echo "*** Is the directory with i386-jos-elf-gcc in your PATH?" 1>&2;   echo "*** If your i386-*-elf toolchain is installed with a command" 1>&2;   echo "*** prefix other than 'i386-jos-elf-', set your TOOLPREFIX" 1>&2;   echo "*** environment variable to that prefix and run 'make' again." 1>&2;   echo "*** To turn off this error, run 'gmake TOOLPREFIX= ...'." 1>&2;   echo "***" 1>&2; exit 1; fi) endif  # If the makefile can't find QEMU, specify its path here # QEMU = qemu-system-i386 # Try to infer the correct QEMU ifndef QEMU QEMU = $(shell if which qemu > /dev/null;   then echo qemu; exit;   elif which qemu-system-i386 > /dev/null;   then echo qemu-system-i386; exit;   elif which qemu-system-x86_64 > /dev/null;   then echo qemu-system-x86_64; exit;   else   qemu=/Applications/Q.app/Contents/MacOS/i386-softmmu.app/Contents/MacOS/i386-softmmu;   if test -x $$qemu; then echo $$qemu; exit; fi; fi;   echo "***" 1>&2;   echo "*** Error: Couldn't find a working QEMU executable." 1>&2;   echo "*** Is the directory containing the qemu binary in your PATH" 1>&2;   echo "*** or have you tried setting the QEMU variable in Makefile?" 1>&2;   echo "***" 1>&2; exit 1) endif  CC = $(TOOLPREFIX)gcc AS = $(TOOLPREFIX)gas LD = $(TOOLPREFIX)ld OBJCOPY = $(TOOLPREFIX)objcopy OBJDUMP = $(TOOLPREFIX)objdump CFLAGS = -fno-pic -static -fno-builtin -fno-strict-aliasing -O2 -Wall -MD -ggdb -m32 -Werror -fno-omit-frame-pointer CFLAGS += $(shell $(CC) -fno-stack-protector -E -x c /dev/null >/dev/null 2>&1 && echo -fno-stack-protector) ASFLAGS = -m32 -gdwarf-2 -Wa,-divide # FreeBSD ld wants ``elf_i386_fbsd'' LDFLAGS += -m $(shell $(LD) -V | grep elf_i386 2>/dev/null | head -n 1) # Disable PIE when possible (for Ubuntu 16.10 toolchain) ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]no-pie'),) CFLAGS += -fno-pie -no-pie endif ifneq ($(shell $(CC) -dumpspecs 2>/dev/null | grep -e '[^f]nopie'),) CFLAGS += -fno-pie -nopie endif  xv6.img: bootblock kernel  dd if=/dev/zero of=xv6.img count=10000  dd if=bootblock of=xv6.img conv=notrunc  dd if=kernel of=xv6.img seek=1 conv=notrunc  xv6memfs.img: bootblock kernelmemfs  dd if=/dev/zero of=xv6memfs.img count=10000  dd if=bootblock of=xv6memfs.img conv=notrunc  dd if=kernelmemfs of=xv6memfs.img seek=1 conv=notrunc  bootblock: bootasm.S bootmain.c  $(CC) $(CFLAGS) -fno-pic -O -nostdinc -I. -c bootmain.c  $(CC) $(CFLAGS) -fno-pic -nostdinc -I. -c bootasm.S  $(LD) $(LDFLAGS) -N -e start -Ttext 0x7C00 -o bootblock.o bootasm.o bootmain.o  $(OBJDUMP) -S bootblock.o > bootblock.asm  $(OBJCOPY) -S -O binary -j .text bootblock.o bootblock  ./sign.pl bootblock  entryother: entryother.S  $(CC) $(CFLAGS) -fno-pic -nostdinc -I. -c entryother.S  $(LD) $(LDFLAGS) -N -e start -Ttext 0x7000 -o bootblockother.o entryother.o  $(OBJCOPY) -S -O binary -j .text bootblockother.o entryother  $(OBJDUMP) -S bootblockother.o > entryother.asm  initcode: initcode.S  $(CC) $(CFLAGS) -nostdinc -I. -c initcode.S  $(LD) $(LDFLAGS) -N -e start -Ttext 0 -o initcode.out initcode.o  $(OBJCOPY) -S -O binary initcode.out initcode  $(OBJDUMP) -S initcode.o > initcode.asm  kernel: $(OBJS) entry.o entryother initcode kernel.ld  $(LD) $(LDFLAGS) -T kernel.ld -o kernel entry.o $(OBJS) -b binary initcode entryother  $(OBJDUMP) -S kernel > kernel.asm  $(OBJDUMP) -t kernel | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > kernel.sym  # kernelmemfs is a copy of kernel that maintains the # disk image in memory instead of writing to a disk. # This is not so useful for testing persistent storage or # exploring disk buffering implementations, but it is # great for testing the kernel on real hardware without # needing a scratch disk. MEMFSOBJS = $(filter-out ide.o,$(OBJS)) memide.o kernelmemfs: $(MEMFSOBJS) entry.o entryother initcode kernel.ld fs.img  $(LD) $(LDFLAGS) -T kernel.ld -o kernelmemfs entry.o  $(MEMFSOBJS) -b binary initcode entryother fs.img  $(OBJDUMP) -S kernelmemfs > kernelmemfs.asm  $(OBJDUMP) -t kernelmemfs | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > kernelmemfs.sym  tags: $(OBJS) entryother.S _init  etags *.S *.c  vectors.S: vectors.pl  ./vectors.pl > vectors.S  ULIB = ulib.o usys.o printf.o umalloc.o  _%: %.o $(ULIB) $(LD) $(LDFLAGS) -N -e main -Ttext 0 -o $@ $^  $(OBJDUMP) -S $@ > $*.asm  $(OBJDUMP) -t $@ | sed '1,/SYMBOL TABLE/d; s/ .* / /; /^$$/d' > $*.sym  _forktest: forktest.o $(ULIB) # forktest has less library code linked in - needs to be small # in order to be able to max out the proc table. $(LD) $(LDFLAGS) -N -e main -Ttext 0 -o _forktest forktest.o ulib.o usys.o  $(OBJDUMP) -S _forktest > forktest.asm  mkfs: mkfs.c fs.h  gcc -Werror -Wall -o mkfs mkfs.c  # Prevent deletion of intermediate files, e.g. cat.o, after first build, so # that disk image changes after first build are persistent until clean.  More # details: # https://www.gnu.org/software/make/manual/html_node/Chained-Rules.html .PRECIOUS: %.o  UPROGS=  _cat  _echo  _forktest  _grep  _init  _kill  _ln  _ls  _mkdir  _rm  _sh  _stressfs  _usertests  _wc  _zombie fs.img: mkfs README $(UPROGS)  ./mkfs fs.img README $(UPROGS)  -include *.d  clean:   rm -f *.tex *.dvi *.idx *.aux *.log *.ind *.ilg   *.o *.d *.asm *.sym vectors.S bootblock entryother   initcode initcode.out kernel xv6.img fs.img kernelmemfs   xv6memfs.img mkfs .gdbinit   $(UPROGS) # make a printout FILES = $(shell grep -v '^#' runoff.list) PRINT = runoff.list runoff.spec README toc.hdr toc.ftr $(FILES)  xv6.pdf: $(PRINT)  ./runoff  ls -l xv6.pdf  print: xv6.pdf  # run in emulators  bochs : fs.img xv6.img  if [ ! -e .bochsrc ]; then ln -s dot-bochsrc .bochsrc; fi  bochs -q  # try to generate a unique GDB port GDBPORT = $(shell expr `id -u` % 5000 + 25000) # QEMU's gdb stub command line changed in 0.11 QEMUGDB = $(shell if $(QEMU) -help | grep -q '^-gdb';   then echo "-gdb tcp::$(GDBPORT)";   else echo "-s -p $(GDBPORT)"; fi) ifndef CPUS CPUS := 2 endif QEMUOPTS = -drive file=fs.img,index=1,media=disk,format=raw -drive file=xv6.img,index=0,media=disk,format=raw -smp $(CPUS) -m 512 $(QEMUEXTRA)  qemu: fs.img xv6.img  $(QEMU) -serial mon:stdio $(QEMUOPTS)  qemu-memfs: xv6memfs.img  $(QEMU) -drive file=xv6memfs.img,index=0,media=disk,format=raw -smp $(CPUS) -m 256  qemu-nox: fs.img xv6.img  $(QEMU) -nographic $(QEMUOPTS)  .gdbinit: .gdbinit.tmpl  sed "s/localhost:1234/localhost:$(GDBPORT)/" < $^ > $@  qemu-gdb: fs.img xv6.img .gdbinit  @echo "*** Now run 'gdb'." 1>&2  $(QEMU) -serial mon:stdio $(QEMUOPTS) -S $(QEMUGDB)  qemu-nox-gdb: fs.img xv6.img .gdbinit  @echo "*** Now run 'gdb'." 1>&2  $(QEMU) -nographic $(QEMUOPTS) -S $(QEMUGDB) # CUT HERE # prepare dist for students # after running make dist, probably want to # rename it to rev0 or rev1 or so on and then # check in that version.  EXTRA=  mkfs.c ulib.c user.h cat.c echo.c forktest.c grep.c kill.c  ln.c ls.c mkdir.c rm.c stressfs.c usertests.c wc.c zombie.c  printf.c umalloc.c  README dot-bochsrc *.pl toc.* runoff runoff1 runoff.list  .gdbinit.tmpl gdbutil  dist:  rm -rf dist  mkdir dist  for i in $(FILES);   do    grep -v PAGEBREAK $$i >dist/$$i;   done sed '/CUT HERE/,$$d' Makefile >dist/Makefile  echo >dist/runoff.spec  cp $(EXTRA) dist  dist-test:  rm -rf dist  make dist  rm -rf dist-test  mkdir dist-test  cp dist/* dist-test  cd dist-test; $(MAKE) print  cd dist-test; $(MAKE) bochs || true cd dist-test; $(MAKE) qemu  # update this rule (change rev#) when it is time to # make a new revision. tar:  rm -rf /tmp/xv6  mkdir -p /tmp/xv6  cp dist/* dist/.gdbinit.tmpl /tmp/xv6  (cd /tmp; tar cf - xv6) | gzip >xv6-rev10.tar.gz  # the next one will be 10 (9/17)  .PHONY: dist-test dist  

解决方法：其实很简单，因为你在fs.img:少了一个空行，可能是修改的时候把这个空行不小心删除了，导致了他的错误。在图示位置将UPROGS结尾加一个空行即可。

  大家好，我叫亓官劼（qí guān jié ），在ImapBox中记录学习的点滴历程，时光荏苒，未来可期，加油~博客地址为：亓官劼的博客，B站昵称为：亓官劼，地址为亓官劼的B站

本文原创为亓官劼，请大家支持原创，部分平台一直在盗取博主的文章！！！