使用 GIT 获得Linux Kernel的代码并查看，追踪历史记录

Linux kernel  的官方 GIT地址是：

http://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git

可以从这个地址拿到 kernel 的 代码仓库。

1. 拿代码仓库

git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git  

2. 查看状态：

3. 更新本地的代码：

$ git pull
Already up-to-date.  

4. 切换到分支：

$ git checkout linux-3.10.y
Checking out files: % (/), done.
Switched to branch 'linux-3.10.y'  

5. 查看分支信息：

$ git branch
* linux-3.10.y
  master 

6. 创建一个新分支：

$ git checkout -b linux-3.10-charles
Switched to a new branch 'linux-3.10-charles'  

$ git branch
* linux-3.10-charles
  linux-3.10.y
  master 

7. 修改文件 init/main.c, 加入一行注释，然后 执行

git add .  

$ git status
# On branch linux-3.10-charles
# Changes to be committed:
#   (use "git reset HEAD <file>..." to unstage)
#
#   modified:   init/main.c
#  

如果选择  revert 命令，相当于 undo  "git add .":

What now> r
           staged     unstaged path
  :        +/-      nothing [i]nit/main.c
Revert>>
reverted one path  

*** Commands ***
  : [s]tatus     : [u]pdate     : [r]evert     : [a]dd untracked
  : [p]atch      : [d]iff   : [q]uit   : [h]elp
What now> q  

这个时候再执行 git status:

$ git status
# On branch linux-3.10-charles
# Changes not staged for commit:
#   (use "git add <file>..." to update what will be committed)
#   (use "git checkout -- <file>..." to discard changes in working directory)
#
#   modified:   init/main.c
#
no changes added to commit (use "git add" and/or "git commit -a")  

8. 提交修改：

$ git commit -a -m "This is just for testing git"
[linux-3.10-charles 9eabb78] This is just for testing git
  file changed,  insertion(+),  deletion(-)  

9. 查看修改记录(git log)：

commit 9eabb788b5c33efed589b1263aedd69b97e592ac
Author: Taotao Ding <htdkd@hotmail.com>
Date:   Wed May  ::  +  

    This is just for testing git  

commit 5d897eedc505bb8af1f4865ae381eadbfd3bc8c1
Author: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date:   Tue May  ::  -  

    Linux 3.10.  

commit 6b32172a1d3cffa74067ced96612bd13658d4fcf
Author: Felipe Balbi <balbi@ti.com>
Date:   Tue Feb  ::  -  

    usb: musb: avoid NULL pointer dereference
     

可以看到，修改已经被记录起来了。

git log  -p
commit 9eabb788b5c33efed589b1263aedd69b97e592ac
Author: Taotao Ding <htdkd@hotmail.com>
Date:   Wed May  ::  +  

    This is just for testing git  

diff --git a/init/main.c b/init/main.c
index e83ac04..febc1e9
--- a/init/main.c
+++ b/init/main.c
@@ -, +, @@
  */  

 #define DEBUG          /* Enable initcall_debug */
-
+/* This is a test line for git */
 #include <linux/types.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>  

10： 查看一个文件最近的修改记录：

$ git log master..HEAD init/main.c
commit 9eabb788b5c33efed589b1263aedd69b97e592ac
Author: Taotao Ding <htdkd@hotmail.com>
Date:   Wed May  ::  +  

    This is just for testing git  

commit b7a52f5111bc53ffbfff96330621cbde80df6ba4
Author: Theodore Ts'o <tytso@mit.edu>
Date:   Tue Sep  ::  -  

    random: run random_int_secret_init() run after all late_initcalls  

    commit 47d06e532e95b71c0db3839ebdef3fe8812fca2c upstream.  

    The some platforms (e.g., ARM) initializes their clocks as
    late_initcalls for some unknown reason.  So make sure
    random_int_secret_init() is run after all of the late_initcalls are
    run.  

    Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>  

11： 比较两个分支的差异：

$ git log linux-3.10.y..linux-3.10-charles
commit 9eabb788b5c33efed589b1263aedd69b97e592ac
Author: Taotao Ding <htdkd@hotmail.com>
Date:   Wed May  ::  +  

    This is just for testing git  

当前分支也可写成  HEAD，所以：

$ git log linux-3.10.y..HEAD
commit 9eabb788b5c33efed589b1263aedd69b97e592ac
Author: Taotao Ding <htdkd@hotmail.com>
Date:   Wed May  ::  +  

    This is just for testing git  

reference:

http://www.opensourceforu.com/2011/05/linux-kernel-development-using-git/

P.S.

配置 username  和 user.email 的方法：

git config    user.email "username"

git config   user.email "email@server"

这两个命令改变 .git/config 配置文件 （local)

git config  --global   user.email "username"

git config   --global user.email "email@server"

git config --global core.editor "vim"
则改变全局的 git 配置文件  （～/.gitconfig)