1. 根目录:
2. include
3. linux
4. nvram.h

#ifndef _LINUX_NVRAM_H
#define _LINUX_NVRAM_H

#include <uapi/linux/nvram.h>

/* __foo is foo without grabbing the rtc_lock - get it yourself */
extern unsigned char __nvram_read_byte(int i);
extern unsigned char nvram_read_byte(int i);
extern void __nvram_write_byte(unsigned char c, int i);
extern void nvram_write_byte(unsigned char c, int i);
extern int __nvram_check_checksum(void);
extern int nvram_check_checksum(void);
#endif  /* _LINUX_NVRAM_H */