29 lines
792 B
Markdown
29 lines
792 B
Markdown
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# printk 说明
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## 头文件
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```cpp
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#include <linux/kernel.h>
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```
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## 函数原型
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```cpp
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int printk(const char *fmt, ...);
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```
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## 参数说明
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在 fmt 字符串前面增加以下宏可以控制 printk 的输出级别，数值越小打印级别越高。当设置的级别地于当前打印级别时，打印信息将不被输出。
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```cpp
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#define KERN_EMERG "<0>" /* system is unusable */
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#define KERN_ALERT "<1>" /* action must be taken immediately */
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#define KERN_CRIT "<2>" /* critical conditions */
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#define KERN_ERR "<3>" /* error conditions */
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#define KERN_WARNING "<4>" /* warning conditions */
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#define KERN_NOTICE "<5>" /* normal but significant condition */
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#define KERN_INFO "<6>" /* informational */
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#define KERN_DEBUG
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```
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