首先必须知道u8,s8等数据类型的定义：

typedef signed char s8;  
typedef unsigned char u8;  
  
typedef signed short s16;  
typedef unsigned short u16;  
  
typedef signed int s32;  
typedef unsigned int u32;  
  
typedef signed long long s64;  
typedef unsigned long long u64;  

与体系结构相关的，定义在include/linux/type.h文件中：

/* bsd */
typedef unsigned char		u_char;
typedef unsigned short		u_short;
typedef unsigned int		u_int;
typedef unsigned long		u_long;

/* sysv */
typedef unsigned char		unchar;
typedef unsigned short		ushort;
typedef unsigned int		uint;
typedef unsigned long		ulong;

#ifndef __BIT_TYPES_DEFINED__
#define __BIT_TYPES_DEFINED__

typedef		__u8		u_int8_t;
typedef		__s8		int8_t;
typedef		__u16		u_int16_t;
typedef		__s16		int16_t;
typedef		__u32		u_int32_t;
typedef		__s32		int32_t;

#endif /* !(__BIT_TYPES_DEFINED__) */

typedef		__u8		uint8_t;
typedef		__u16		uint16_t;
typedef		__u32		uint32_t;

#if defined(__GNUC__)
typedef		__u64		uint64_t;
typedef		__u64		u_int64_t;
typedef		__s64		int64_t;

对于各种数据类型的打印方式总结如下如下：

待解问题，在linux kernel里面也有使用bool来定义变量，查看code，定义如下：

typedef _Bool           bool;  

但是并没有真正找到具体定义在何处，待解。下面是stdbool.h的source code：

#define _STDBOOL_H

#ifndef __cplusplus

#define bool	_Bool
#define true	1
#define false	0

#else /* __cplusplus */

/* Supporting _Bool in C++ is a GCC extension.  */
#define _Bool	bool

#if __cplusplus < 201103L
/* Defining these macros in C++98 is a GCC extension.  */
#define bool	bool
#define false	false
#define true	true
#endif

#endif /* __cplusplus */

/* Signal that all the definitions are present.  */
#define __bool_true_false_are_defined	1

#endif	/* stdbool.h */

也大致解释了linux kernel bool type了。
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