sys_kpmap
kpmap->header[0].offset = offsetof(struct sys_kpmap, version);
kpmap->header[1].offset = offsetof(struct sys_kpmap, upticks);
kpmap->header[2].offset = offsetof(struct sys_kpmap, ts_uptime);
kpmap->header[3].offset = offsetof(struct sys_kpmap, ts_realtime);
kpmap->header[4].offset = offsetof(struct sys_kpmap, tsc_freq);
kpmap->header[5].offset = offsetof(struct sys_kpmap, tick_freq);
kpmap->header[6].offset = offsetof(struct sys_kpmap, fast_gtod);
struct sys_kpmap *kpmap;
extern struct sys_kpmap *kpmap;