pintos/src/threads/build，下输入make 命令，然后再输入 make check 命令来测试，输入 make clean 来清空之前编译的结果的，那么这个目录下的Makefile应该是一个总的Makefile了，看看这个Makefile里面的内容，一点一点来解析吧！

# -*- makefile -*-

SRCDIR = ../..

#所有存放源文件的目录，也就是 pintos/src/

all: kernel.bin loader.bin

#这个all是标签，Makefile中的第一个目标会被作为其默认目标，由于伪目标的特性是，总是被执行的，

#所以其依赖的 kernel.bin loader.bin 就总是不如“all”这个目标新。所以，这2个二进制文件总会更新

include ../../Make.config

include ../Make.vars

include ../../tests/Make.tests

这个是Makefile的前面几行，all是个标签，输入命令 make all 的话就会运行 kernel.bin loader.bin 这2个程序

然后看到 include 了一个文件，去看看 pintos/src/Make.config

那么对3个这Makefile的文件的解析我都写在这里了：

首先是../../Make.config:

# -*- makefile -*-

SHELL = /bin/sh

#指定使用的shell

VPATH = $(SRCDIR)

#特殊变量 VPATH 指定文件的查找路径

# Binary utilities.

# If the host appears to be x86, use the normal tools.

# If its x86-64, use the compiler and linker in 32-bit mode.

# Otherwise assume cross-tools are installed as i386-elf-*.

X86 = i.86\|pentium.*\|\|nexgen\|viac3\|6x86\|athlon.*\|i86pc

# .*是模糊匹配，\|是管道的转义

X86_64 = x86_64

# Pintos doesnt compile/run properly using gcc 4.3+. Force 4.1 for now.

# 这句话的意思大概是 必须是4.1版本的gcc 才可以正常编译

CCPROG = /usr/class/cs140/x86_64/bin/i586-elf-gcc

ifeq ($(strip $(shell command -v $(CCPROG) 2 /dev/null)),)

#strip函数：功能：去掉string字串中开头和结尾的空字符。返回被去掉空格的字符串值。

#如果strip这个函数返回为空的话

#strip是函数名， 函数参数是 $(shell command -v $(CCPROG) 2 /dev/null) ，单独的一个变量

#参考博客： http://www.cnblogs.com/bethal/p/5430229.html

# 这个函数会新生成一个Shell程序来执行命令

CCPROG = gcc

endif

ifneq (0, $(shell expr `uname -m` : $(X86)))

CC = $(CCPROG)

LD = ld

OBJCOPY = objcopy

else

ifneq (0, $(shell expr `uname -m` : $(X86_64)))

CC = $(CCPROG) -m32

LD = ld -melf_i386

OBJCOPY = objcopy

else

CC = i386-elf-gcc

LD = i386-elf-ld

OBJCOPY = i386-elf-objcopy

endif

endif

ifeq ($(strip $(shell command -v $(CC) 2 /dev/null)),)

$(warning *** Compiler ($(CC)) not found. Did you set $$PATH properly? Please refer to the Getting Started section in the documentation for details. ***)

endif

# Compiler and assembler invocation.

DEFINES =

WARNINGS = -Wall -W -Wstrict-prototypes -Wmissing-prototypes -Wsystem-headers

CFLAGS = -g -msoft-float -O

CPPFLAGS = -nostdinc -I$(SRCDIR) -I$(SRCDIR)/lib

ASFLAGS = -Wa,--gstabs

LDFLAGS =

DEPS = -MMD -MF $(@:.o=.d)

# Turn off -fstack-protector, which we dont support.

ifeq ($(strip $(shell echo | $(CC) -fno-stack-protector -E - /dev/null 21; echo $$?)),0)

CFLAGS += -fno-stack-protector

endif

# Turn off --build-id in the linker, which confuses the Pintos loader.

ifeq ($(strip $(shell $(LD) --help | grep -q build-id; echo $$?)),0)

LDFLAGS += -Wl,--build-id=none

endif

如有不明者，还请咨询专业人士。