fix unrecognized image links

Initialization/linux-initialization-6.md

@@ -94,7 +94,7 @@ noexec		[X86]
 
 我们可以在启动的时候看到:
 
-![NX](http://oi62.tinypic.com/swwxhy.jpg)
+![NX](images/NX.png)
 
 之后我们可以看到下面函数的调用:   
 
@@ -471,7 +471,7 @@ void  __init early_alloc_pgt_buf(void)
 
 我们也可以使用 `readelf` 工具来找到它:    
 
-![brk area](http://oi61.tinypic.com/71lkeu.jpg) 
+![brk area](images/brk_area.png) 
 
 之后我们用 `_pa` 宏得到了新的 `brk` 区段的物理地址，我们计算页表缓冲区的基地址和结束地址。因为我们之前已经创建好了页面缓冲区，所以现在我们使用 `reserve_brk` 函数为 `brk` 区段保留内存块:   
 

Initialization/linux-initialization-7.md

@@ -390,7 +390,7 @@ void __init setup_nr_cpu_ids(void)
 
 Here `nr_cpu_ids` represents number of CPUs, `NR_CPUS` represents the maximum number of CPUs which we can set in configuration time:
 
-![CONFIG_NR_CPUS](http://oi59.tinypic.com/28mh45h.jpg)
+![CONFIG_NR_CPUS](images/CONFIG_NR_CPUS.png)
 
 Actually we need to call this function, because `NR_CPUS` can be greater than actual amount of the CPUs in the your computer. Here we can see that we call `find_last_bit` function and pass two parameters to it:
 

Initialization/linux-initialization-8.md

@@ -178,7 +178,7 @@ and initializes handler for the `CPU` [hotplug](https://www.kernel.org/doc/Docum
 
 After this we can see the kernel command line in the initialization output:
 
-![kernel command line](http://oi58.tinypic.com/2m7vz10.jpg)
+![kernel command line](images/kernel_command_line.png)
 
 And a couple of functions such as `parse_early_param` and `parse_args` which handles linux kernel command line. You may remember that we already saw the call of the `parse_early_param` function in the sixth [part](/Initialization/linux-initialization-6.md) of the kernel initialization chapter, so why we call it again? Answer is simple: we call this function in the architecture-specific code (`x86_64` in our case), but not all architecture calls this function. And we need to call the second function `parse_args` to parse and handle non-early command line arguments.