As per http://lkml.org/lkml/2003/12/1/150 diff -urN --exclude=CVS --exclude=.cvsignore linux-2.4.23/include/linux/mc146818rtc.h linux-cvs-2.4.23/include/linux/mc146818rtc.h --- linux-2.4.23/include/linux/mc146818rtc.h 2001-11-22 20:46:58.000000000 +0100 +++ linux-cvs-2.4.23/include/linux/mc146818rtc.h 2003-11-28 15:09:41.000000000 +0100 @@ -98,4 +98,12 @@ #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10) #endif +#ifndef RTC_IO_EXTENT +#define RTC_IO_EXTENT 0x10 /* Only really two ports, but... */ +#endif + +#ifndef RTC_IOMAPPED +#define RTC_IOMAPPED 1 /* Default to I/O mapping. */ +#endif + #endif /* _MC146818RTC_H */