/*
 * ----------------------------------------------------------------------------
 * "THE BEER-WARE LICENSE" (Revision 42):
 * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
 * can do whatever you want with this stuff. If we meet some day, and you think
 * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
 * ----------------------------------------------------------------------------
 *
 * refclock_oncore.c
 *
 * Driver for some of the various the Motorola Oncore GPS receivers.
 *   should work with Basic, PVT6, VP, UT, UT+, GT, GT+, SL, M12, M12+T
 *	The receivers with TRAIM (VP, UT, UT+, M12+T), will be more accurate
 *	than the others.
 *	The receivers without position hold (GT, GT+) will be less accurate.
 *
 * Tested with:
 *
 *		(UT)				   (VP)
 *   COPYRIGHT 1991-1997 MOTOROLA INC.	COPYRIGHT 1991-1996 MOTOROLA INC.
 *   SFTW P/N #     98-P36848P		SFTW P/N # 98-P36830P
 *   SOFTWARE VER # 2			SOFTWARE VER # 8
 *   SOFTWARE REV # 2			SOFTWARE REV # 8
 *   SOFTWARE DATE  APR 24 1998 	SOFTWARE DATE  06 Aug 1996
 *   MODEL #	R1121N1114		MODEL #    B4121P1155
 *   HWDR P/N # 1			HDWR P/N # _
 *   SERIAL #	R0010A			SERIAL #   SSG0226478
 *   MANUFACTUR DATE 6H07		MANUFACTUR DATE 7E02
 *					OPTIONS LIST	IB
 *
 *	      (Basic)				   (M12)
 *   COPYRIGHT 1991-1994 MOTOROLA INC.	COPYRIGHT 1991-2000 MOTOROLA INC.
 *   SFTW P/N # 98-P39949M		SFTW P/N # 61-G10002A
 *   SOFTWARE VER # 5			SOFTWARE VER # 1
 *   SOFTWARE REV # 0			SOFTWARE REV # 3
 *   SOFTWARE DATE  20 JAN 1994 	SOFTWARE DATE  Mar 13 2000
 *   MODEL #	A11121P116		MODEL #    P143T12NR1
 *   HDWR P/N # _			HWDR P/N # 1
 *   SERIAL #	SSG0049809		SERIAL #   P003UD
 *   MANUFACTUR DATE 417AMA199		MANUFACTUR DATE 0C27
 *   OPTIONS LIST    AB
 *
 *	      (M12+T)				  (M12+T later version)
 *   COPYRIGHT 1991-2002 MOTOROLA INC.	COPYRIGHT 1991-2003 MOTOROLA INC.
 *   SFTW P/N #     61-G10268A		SFTW P/N #     61-G10268A
 *   SOFTWARE VER # 2			SOFTWARE VER # 2
 *   SOFTWARE REV # 0			SOFTWARE REV # 1
 *   SOFTWARE DATE  AUG 14 2002 	SOFTWARE DATE  APR 16 2003
 *   MODEL #	P283T12T11		MODEL #    P273T12T12
 *   HWDR P/N # 2			HWDR P/N # 2
 *   SERIAL #	P04DC2			SERIAL #   P05Z7Z
 *   MANUFACTUR DATE 2J17		MANUFACTUR DATE 3G15
 *
 * --------------------------------------------------------------------------
 * Reg Clemens (Feb 2006)
 * Fix some gcc4 compiler complaints
 * Fix possible segfault in oncore_init_shmem
 * change all (possible) fprintf(stderr, to record_clock_stats
 * Apply patch from Russell J. Yount <rjy@cmu.edu> Fixed (new) MT12+T UTC not correct
 *   immediately after new Almanac Read.
 * Apply patch for new PPS implementation by Rodolfo Giometti <giometti@linux.it>
 *   now code can use old Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de> or
 *   the new one.  Compiles depending on timepps.h seen.
 * --------------------------------------------------------------------------
 * Luis Batanero Guerrero <luisba@rao.es> (Dec 2005) Patch for leap seconds
 * (the oncore driver was setting the wrong ntpd variable)
 * --------------------------------------------------------------------------
 * Reg.Clemens (Mar 2004)
 * Support for interfaces other than PPSAPI removed, for Solaris, SunOS,
 * SCO, you now need to use one of the timepps.h files in the root dir.
 * this driver will 'grab' it for you if you dont have one in /usr/include
 * --------------------------------------------------------------------------
 * This code uses the two devices
 *	/dev/oncore.serial.n
 *	/dev/oncore.pps.n
 * which may be linked to the same device.
 * and can read initialization data from the file
 *	/etc/ntp.oncoreN, /etc/ntp.oncore.N, or /etc/ntp.oncore, where
 *	n or N are the unit number, viz 127.127.30.N.
 * --------------------------------------------------------------------------
 * Reg.Clemens <reg@dwf.com> Sep98.
 *  Original code written for FreeBSD.
 *  With these mods it works on FreeBSD, SunOS, Solaris and Linux
 *    (SunOS 4.1.3 + ppsclock)
 *    (Solaris7 + MU4)
 *    (RedHat 5.1 2.0.35 + PPSKit, 2.1.126 + or later).
 *
 *  Lat,Long,Ht, cable-delay, offset, and the ReceiverID (along with the
 *  state machine state) are printed to CLOCKSTATS if that file is enabled
 *  in /etc/ntp.conf.
 *
 * --------------------------------------------------------------------------
 *
 * According to the ONCORE manual (TRM0003, Rev 3.2, June 1998, page 3.13)
 * doing an average of 10000 valid 2D and 3D fixes is what the automatic
 * site survey mode does.  Looking at the output from the receiver
 * it seems like it is only using 3D fixes.
 * When we do it ourselves, take 10000 3D fixes.
 */

#define POS_HOLD_AVERAGE	10000	/* nb, 10000s ~= 2h45m */

/*
 * ONCORE_SHMEM_STATUS will create a mmap(2)'ed file named according to a
 * "STATUS" line in the oncore config file, which contains the most recent
 * copy of all types of messages we recognize.	This file can be mmap(2)'ed
 * by monitoring and statistics programs.
 *
 * See separate HTML documentation for this option.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#if defined(REFCLOCK) && defined(CLOCK_ONCORE)

#include "ntpd.h"
#include "ntp_io.h"
#include "ntp_unixtime.h"
#include "ntp_refclock.h"
#include "ntp_stdlib.h"

#include <stdio.h>
#include <ctype.h>
#include <sys/stat.h>
#ifdef ONCORE_SHMEM_STATUS
# ifdef HAVE_SYS_MMAN_H
#  include <sys/mman.h>
#  ifndef MAP_FAILED
#   define MAP_FAILED ((u_char *) -1)
#  endif  /* MAP_FAILED */
# endif /* HAVE_SYS_MMAN_H */
#endif /* ONCORE_SHMEM_STATUS */

#ifdef HAVE_PPSAPI
# include "ppsapi_timepps.h"
#endif

#ifdef HAVE_SYS_SIO_H
# include <sys/sio.h>
#endif

enum receive_state {
	ONCORE_NO_IDEA,
	ONCORE_CHECK_ID,
	ONCORE_CHECK_CHAN,
	ONCORE_HAVE_CHAN,
	ONCORE_RESET_SENT,
	ONCORE_TEST_SENT,
	ONCORE_INIT,
	ONCORE_ALMANAC,
	ONCORE_RUN
};

enum site_survey_state {
	ONCORE_SS_UNKNOWN,
	ONCORE_SS_TESTING,
	ONCORE_SS_HW,
	ONCORE_SS_SW,
	ONCORE_SS_DONE
};

enum antenna_state {
      ONCORE_ANTENNA_UNKNOWN = -1,
      ONCORE_ANTENNA_OK      =	0,
      ONCORE_ANTENNA_OC      =	1,
      ONCORE_ANTENNA_UC      =	2,
      ONCORE_ANTENNA_NV      =	3
};

/* Model Name, derived from the @@Cj message.
 * Used to initialize some variables.
 */

enum oncore_model {
	ONCORE_BASIC,
	ONCORE_PVT6,
	ONCORE_VP,
	ONCORE_UT,
	ONCORE_UTPLUS,
	ONCORE_GT,
	ONCORE_GTPLUS,
	ONCORE_SL,
	ONCORE_M12,
	ONCORE_UNKNOWN
};

/* the bits that describe these properties are in the same place
 * on the VP/UT, but have moved on the M12.  As such we extract
 * them, and use them from this struct.
 *
 */

struct RSM {
	u_char	posn0D;
	u_char	posn2D;
	u_char	posn3D;
	u_char	bad_almanac;
	u_char	bad_fix;
};

/* It is possible to test the VP/UT each cycle (@@Ea or equivalent) to
 * see what mode it is in.  The bits on the M12 are multiplexed with
 * other messages, so we have to 'keep' the last known mode here.
 */

enum posn_mode {
	MODE_UNKNOWN,
	MODE_0D,
	MODE_2D,
	MODE_3D
};

struct instance {
	int	unit;		/* 127.127.30.unit */
	struct	refclockproc *pp;
	struct	peer *peer;

	int	ttyfd;		/* TTY file descriptor */
	int	ppsfd;		/* PPS file descriptor */
	int	shmemfd;	/* Status shm descriptor */
	pps_handle_t pps_h;
	pps_params_t pps_p;
	enum receive_state o_state;		/* Receive state */
	enum posn_mode mode;			/* 0D, 2D, 3D */
	enum site_survey_state site_survey;	/* Site Survey state */
	enum antenna_state ant_state;		/* antenna state */

	int	Bj_day;

	u_long	delay;		/* ns */
	long	offset; 	/* ns */

	u_char	*shmem;
	char	*shmem_fname;
	u_int	shmem_Cb;
	u_int	shmem_Ba;
	u_int	shmem_Ea;
	u_int	shmem_Ha;
	u_char	shmem_reset;
	u_char	shmem_Posn;
	u_char	shmem_bad_Ea;
	u_char	almanac_from_shmem;

	double	ss_lat;
	double	ss_long;
	double	ss_ht;
	double	dH;
	int	ss_count;
	u_char	posn_set;

	enum oncore_model model;
	u_int	version;
	u_int	revision;

	u_char	chan;		/* 6 for PVT6 or BASIC, 8 for UT/VP, 12 for m12, 0 if unknown */
	s_char	traim;		/* do we have traim? yes UT/VP, M12+T, no BASIC, GT, M12, -1 unknown, 0 no, +1 yes */
				/* the following 7 are all timing counters */
	u_char	traim_delay;	/* seconds counter, waiting for reply */
	u_char	count;		/* cycles thru Ea before starting */
	u_char	count1; 	/* cycles thru Ea after SS_TESTING, waiting for SS_HW */
	u_char	count2; 	/* cycles thru Ea after count, to check for @@Ea */
	u_char	count3; 	/* cycles thru Ea checking for # channels */
	u_char	count4; 	/* cycles thru leap after Gj to issue Bj */
	u_char	count5; 	/* cycles thru get_timestamp waiting for valid UTC correction */
	u_char	count5_set;	/* only set count5 once */
	u_char	pollcnt;
	u_char	timeout;	/* count to retry Cj after Fa self-test */

	struct	RSM rsm;	/* bits extracted from Receiver Status Msg in @@Ea */
	u_char	printed;
	u_char	polled;
	u_long	ev_serial;
	int	Rcvptr;
	u_char	Rcvbuf[500];
	u_char	BEHa[160];	/* Ba, Ea or Ha */
	u_char	BEHn[80];	/* Bn , En , or Hn */
	u_char	Cj[300];
	u_char	Ag;		/* Satellite mask angle */
	u_char	saw_At;
	u_char	saw_Ay;
	u_char	saw_Az;
	s_char	saw_Gj;
	u_char	have_dH;
	u_char	init_type;
	s_char	saw_tooth;
	s_char	chan_in;	/* chan number from INPUT, will always use it */
	u_char	chan_id;	/* chan number determined from part number */
	u_char	chan_ck;	/* chan number determined by sending commands to hardware */
	s_char	traim_in;	/* TRAIM from INPUT, will always use ON/OFF specified */
	s_char	traim_id;	/* TRAIM determined from part number */
	u_char	traim_ck;	/* TRAIM determined by sending commands to hardware */
	u_char	once;		/* one pass code at top of BaEaHa */
	s_char	assert;
	u_char	hardpps;
};

#define rcvbuf	instance->Rcvbuf
#define rcvptr	instance->Rcvptr

static	int	oncore_start	      P((int, struct peer *));
static	void	oncore_poll	      P((int, struct peer *));
static	void	oncore_shutdown       P((int, struct peer *));
static	void	oncore_consume	      P((struct instance *));
static	void	oncore_read_config    P((struct instance *));
static	void	oncore_receive	      P((struct recvbuf *));
static	int	oncore_ppsapi	      P((struct instance *));
static	void	oncore_get_timestamp  P((struct instance *, long, long));
static	void	oncore_init_shmem     P((struct instance *));

static	void	oncore_antenna_report P((struct instance *, enum antenna_state));
static	void	oncore_chan_test      P((struct instance *));
static	void	oncore_check_almanac  P((struct instance *));
static	void	oncore_check_antenna  P((struct instance *));
static	void	oncore_check_leap_sec P((struct instance *));
static	int	oncore_checksum_ok    P((u_char *, int));
static	void	oncore_compute_dH     P((struct instance *));
static	void	oncore_load_almanac   P((struct instance *));
static	void	oncore_print_Cb       P((struct instance *, u_char *));
/* static  void    oncore_print_array	 P((u_char *, int));	*/
static	void	oncore_print_posn     P((struct instance *));
static	void	oncore_sendmsg	      P((int, u_char *, size_t));
static	void	oncore_set_posn       P((struct instance *));
static	void	oncore_set_traim      P((struct instance *));
static	void	oncore_shmem_get_3D   P((struct instance *));
static	void	oncore_ss	      P((struct instance *));
static	int	oncore_wait_almanac   P((struct instance *));

static	void	oncore_msg_any	   P((struct instance *, u_char *, size_t, int));
static	void	oncore_msg_Adef    P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Ag	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_As	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_At	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Ay	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Az	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_BaEaHa  P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Bd	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Bj	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_BnEnHn  P((struct instance *, u_char *, size_t));
static	void	oncore_msg_CaFaIa  P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Cb	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Cf	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Cj	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Cj_id   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Cj_init P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Ga	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Gb	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Gj	   P((struct instance *, u_char *, size_t));
static	void	oncore_msg_Sz	   P((struct instance *, u_char *, size_t));

struct	refclock refclock_oncore = {
	oncore_start,		/* start up driver */
	oncore_shutdown,	/* shut down driver */
	oncore_poll,		/* transmit poll message */
	noentry,		/* not used */
	noentry,		/* not used */
	noentry,		/* not used */
	NOFLAGS 		/* not used */
};

/*
 * Understanding the next bit here is not easy unless you have a manual
 * for the the various Oncore Models.
 */

static struct msg_desc {
	const char	flag[3];
	const int	len;
	void		(*handler) P((struct instance *, u_char *, size_t));
	const char	*fmt;
	int		shmem;
} oncore_messages[] = {
			/* Ea and En first since they're most common */
	{ "Ea",  76,    oncore_msg_BaEaHa, "mdyyhmsffffaaaaoooohhhhmmmmvvhhddtntimsdimsdimsdimsdimsdimsdimsdimsdsC" },
	{ "Ba",  68,    oncore_msg_BaEaHa, "mdyyhmsffffaaaaoooohhhhmmmmvvhhddtntimsdimsdimsdimsdimsdimsdsC" },
	{ "Ha", 154,    oncore_msg_BaEaHa, "mdyyhmsffffaaaaoooohhhhmmmmaaaaoooohhhhmmmmVVvvhhddntimsiddimsiddimsiddimsiddimsiddimsiddimsiddimsiddimsiddimsiddimsiddimsiddssrrccooooTTushmvvvvvvC" },
	{ "Bn",  59,    oncore_msg_BnEnHn, "otaapxxxxxxxxxxpysreensffffsffffsffffsffffsffffsffffC" },
	{ "En",  69,    oncore_msg_BnEnHn, "otaapxxxxxxxxxxpysreensffffsffffsffffsffffsffffsffffsffffsffffC" },
	{ "Hn",  78,    oncore_msg_BnEnHn, "" },
	{ "Ab",  10,    0,                 "" },
	{ "Ac",  11,    0,                 "" },
	{ "Ad",  11,    oncore_msg_Adef,   "" },
	{ "Ae",  11,    oncore_msg_Adef,   "" },
	{ "Af",  15,    oncore_msg_Adef,   "" },
	{ "Ag",   8,    oncore_msg_Ag,     "" }, /* Satellite mask angle */
	{ "As",  20,    oncore_msg_As,     "" },
	{ "At",   8,    oncore_msg_At,     "" },
	{ "Au",  12,    0,                 "" },
	{ "Av",   8,    0,                 "" },
	{ "Aw",   8,    0,                 "" },
	{ "Ay",  11,    oncore_msg_Ay,     "" },
	{ "Az",  11,    oncore_msg_Az,     "" },
	{ "AB",   8,    0,                 "" },
	{ "Bb",  92,    0,                 "" },
	{ "Bd",  23,    oncore_msg_Bd,     "" },
	{ "Bj",   8,    oncore_msg_Bj,     "" },
	{ "Ca",   9,    oncore_msg_CaFaIa, "" },
	{ "Cb",  33,    oncore_msg_Cb,     "" },
	{ "Cf",   7,    oncore_msg_Cf,     "" },
	{ "Cg",   8,    0,                 "" },
	{ "Ch",   9,    0,                 "" },
	{ "Cj", 294,    oncore_msg_Cj,     "" },
	{ "Ek",  71,    0,                 "" },
	{ "Fa",   9,    oncore_msg_CaFaIa, "" },
	{ "Ga",  20,    oncore_msg_Ga,     "" },
	{ "Gb",  17,    oncore_msg_Gb,     "" },
	{ "Gc",   8,    0,                 "" },
	{ "Gd",   8,    0,                 "" },
	{ "Ge",   8,    0,                 "" },
	{ "Gj",  21,    oncore_msg_Gj,     "" },
	{ "Ia",  10,    oncore_msg_CaFaIa, "" },
	{ "Sz",   8,    oncore_msg_Sz,     "" },
	{ {0},	  7,	0,		   "" }
};


static u_char oncore_cmd_Aa[]  = { 'A', 'a', 0, 0, 0 }; 			    /* 6/8	Time of Day				*/
static u_char oncore_cmd_Ab[]  = { 'A', 'b', 0, 0, 0 }; 			    /* 6/8	GMT Correction				*/
static u_char oncore_cmd_AB[]  = { 'A', 'B', 4 };				    /* VP	Application Type: Static		*/
static u_char oncore_cmd_Ac[]  = { 'A', 'c', 0, 0, 0, 0 };			    /* 6/8	Date					*/
static u_char oncore_cmd_Ad[]  = { 'A', 'd', 0,0,0,0 }; 			    /* 6/8	Latitude				*/
static u_char oncore_cmd_Ae[]  = { 'A', 'e', 0,0,0,0 }; 			    /* 6/8	Longitude				*/
static u_char oncore_cmd_Af[]  = { 'A', 'f', 0,0,0,0, 0 };			    /* 6/8	Height					*/
static u_char oncore_cmd_Ag[]  = { 'A', 'g', 0 };				    /* 6/8/12	Satellite Mask Angle			*/
static u_char oncore_cmd_Agx[] = { 'A', 'g', 0xff };				    /* 6/8/12	Satellite Mask Angle: read		*/
static u_char oncore_cmd_As[]  = { 'A', 's', 0,0,0,0, 0,0,0,0, 0,0,0,0, 0 };	    /* 6/8/12	Posn Hold Parameters			*/
static u_char oncore_cmd_Asx[] = { 'A', 's', 0x7f,0xff,0xff,0xff,		    /* 6/8/12	Posn Hold Readback			*/
					     0x7f,0xff,0xff,0xff,		    /*		 on UT+ this doesnt work with 0xff	*/
					     0x7f,0xff,0xff,0xff, 0xff };	    /*		 but does work with 0x7f (sigh).	*/
static u_char oncore_cmd_At0[] = { 'A', 't', 0 };				    /* 6/8	Posn Hold: off				*/
static u_char oncore_cmd_At1[] = { 'A', 't', 1 };				    /* 6/8	Posn Hold: on				*/
static u_char oncore_cmd_At2[] = { 'A', 't', 2 };				    /* 6/8	Posn Hold: Start Site Survey		*/
static u_char oncore_cmd_Atx[] = { 'A', 't', 0xff };				    /* 6/8	Posn Hold: Read Back			*/
static u_char oncore_cmd_Au[]  = { 'A', 'u', 0,0,0,0, 0 };			    /* GT/M12	Altitude Hold Ht.			*/
static u_char oncore_cmd_Av0[] = { 'A', 'v', 0 };				    /* VP/GT	Altitude Hold: off			*/
static u_char oncore_cmd_Av1[] = { 'A', 'v', 1 };				    /* VP/GT	Altitude Hold: on			*/
static u_char oncore_cmd_Aw[]  = { 'A', 'w', 1 };				    /* 6/8/12	UTC/GPS time selection			*/
static u_char oncore_cmd_Ay[]  = { 'A', 'y', 0, 0, 0, 0 };			    /* Timing	1PPS time offset: set			*/
static u_char oncore_cmd_Ayx[] = { 'A', 'y', 0xff, 0xff, 0xff, 0xff };		    /* Timing	1PPS time offset: Read			*/
static u_char oncore_cmd_Az[]  = { 'A', 'z', 0, 0, 0, 0 };			    /* 6/8UT/12 1PPS Cable Delay: set			*/
static u_char oncore_cmd_Azx[] = { 'A', 'z', 0xff, 0xff, 0xff, 0xff };		    /* 6/8UT/12 1PPS Cable Delay: Read			*/
static u_char oncore_cmd_Ba0[] = { 'B', 'a', 0 };				    /* 6	Position/Data/Status: off		*/
static u_char oncore_cmd_Ba[]  = { 'B', 'a', 1 };				    /* 6	Position/Data/Status: on		*/
static u_char oncore_cmd_Bb[]  = { 'B', 'b', 1 };				    /* 6/8/12	Visible Satellites			*/
static u_char oncore_cmd_Bd[]  = { 'B', 'd', 1 };				    /* 6/8/12?	Almanac Status Msg.			*/
static u_char oncore_cmd_Be[]  = { 'B', 'e', 1 };				    /* 6/8/12	Request Almanac Data			*/
static u_char oncore_cmd_Bj[]  = { 'B', 'j', 0 };				    /* 6/8	Leap Second Pending			*/
static u_char oncore_cmd_Bn0[] = { 'B', 'n', 0, 1, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 6	TRAIM setup/status: msg off, traim on	*/
static u_char oncore_cmd_Bn[]  = { 'B', 'n', 1, 1, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 6	TRAIM setup/status: msg on,  traim on	*/
static u_char oncore_cmd_Bnx[] = { 'B', 'n', 0, 0, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 6	TRAIM setup/status: msg off, traim off	*/
static u_char oncore_cmd_Ca[]  = { 'C', 'a' };					    /* 6	Self Test				*/
static u_char oncore_cmd_Cf[]  = { 'C', 'f' };					    /* 6/8/12	Set to Defaults 			*/
static u_char oncore_cmd_Cg[]  = { 'C', 'g', 1 };				    /* VP	Posn Fix/Idle Mode			*/
static u_char oncore_cmd_Cj[]  = { 'C', 'j' };					    /* 6/8/12	Receiver ID				*/
static u_char oncore_cmd_Ea0[] = { 'E', 'a', 0 };				    /* 8	Position/Data/Status: off		*/
static u_char oncore_cmd_Ea[]  = { 'E', 'a', 1 };				    /* 8	Position/Data/Status: on		*/
static u_char oncore_cmd_Ek[]  = { 'E', 'k', 0 }; /* just turn off */		    /* 8	Posn/Status/Data - extension		*/
static u_char oncore_cmd_En0[] = { 'E', 'n', 0, 1, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 8/GT	TRAIM setup/status: msg off, traim on	*/
static u_char oncore_cmd_En[]  = { 'E', 'n', 1, 1, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 8/GT	TRAIM setup/status: msg on,  traim on	*/
static u_char oncore_cmd_Enx[] = { 'E', 'n', 0, 0, 0,10, 2, 0,0,0, 0,0,0,0,0,0,0 }; /* 8/GT	TRAIM setup/status: msg off, traim off	*/
static u_char oncore_cmd_Fa[]  = { 'F', 'a' };					    /* 8	Self Test				*/
static u_char oncore_cmd_Ga[]  = { 'G', 'a', 0,0,0,0, 0,0,0,0, 0,0,0,0, 0 };	    /* 12	Position Set				*/
static u_char oncore_cmd_Gax[] = { 'G', 'a', 0xff, 0xff, 0xff, 0xff,		    /* 12	Position Set: Read			*/
					     0xff, 0xff, 0xff, 0xff,		    /*							*/
					     0xff, 0xff, 0xff, 0xff, 0xff };	    /*							*/
static u_char oncore_cmd_Gb[]  = { 'G', 'b', 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };	    /* 12	set Date/Time				*/
static u_char oncore_cmd_Gc[]  = { 'G', 'c', 1 };				    /* 12	PPS Control: On Cont			*/
static u_char oncore_cmd_Gd0[] = { 'G', 'd', 0 };				    /* 12	Position Control: 3D (no hold)		*/
static u_char oncore_cmd_Gd1[] = { 'G', 'd', 1 };				    /* 12	Position Control: 0D (3D hold)		*/
static u_char oncore_cmd_Gd2[] = { 'G', 'd', 2 };				    /* 12	Position Control: 2D (Alt Hold) 	*/
static u_char oncore_cmd_Gd3[] = { 'G', 'd', 3 };				    /* 12	Position Coltrol: Start Site Survey	*/
static u_char oncore_cmd_Ge0[] = { 'G', 'e', 0 };				    /* M12+T	TRAIM: off				*/
static u_char oncore_cmd_Ge[]  = { 'G', 'e', 1 };				    /* M12+T	TRAIM: on				*/
static u_char oncore_cmd_Gj[]  = { 'G', 'j' };					    /* 8?/12	Leap Second Pending			*/
static u_char oncore_cmd_Ha0[] = { 'H', 'a', 0 };				    /* 12	Position/Data/Status: off		*/
static u_char oncore_cmd_Ha[]  = { 'H', 'a', 1 };				    /* 12	Position/Data/Status: on		*/
static u_char oncore_cmd_Hn0[] = { 'H', 'n', 0 };				    /* 12	TRAIM Status: off			*/
static u_char oncore_cmd_Hn[]  = { 'H', 'n', 1 };				    /* 12	TRAIM Status: on			*/
static u_char oncore_cmd_Ia[]  = { 'I', 'a' };					    /* 12	Self Test				*/

/* it appears that as of 1997/1998, the UT had As,At, but not Au,Av
 *				    the GT had Au,Av, but not As,At
 * This was as of v2.0 of both firmware sets. possibly 1.3 for UT.
 * Bj in UT at v1.3
 * dont see Bd in UT/GT thru 1999
 * Gj in UT as of 3.0, 1999 , Bj as of 1.3
 */

static char *Month[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jly",
	"Aug", "Sep", "Oct", "Nov", "Dec" };

#define DEVICE1 	"/dev/oncore.serial.%d" /* name of serial device */
#define DEVICE2 	"/dev/oncore.pps.%d"    /* name of pps device */

#define SPEED		B9600		/* Oncore Binary speed (9600 bps) */

/*
 * Assemble and disassemble 32bit signed quantities from a buffer.
 *
 */

	/* to buffer, int w, u_char *buf */
#define w32_buf(buf,w)	{ u_int i_tmp;			   \
			  i_tmp = (w<0) ? (~(-w)+1) : (w); \
			  (buf)[0] = (i_tmp >> 24) & 0xff; \
			  (buf)[1] = (i_tmp >> 16) & 0xff; \
			  (buf)[2] = (i_tmp >>	8) & 0xff; \
			  (buf)[3] = (i_tmp	 ) & 0xff; \
			}

#define w32(buf)      (((buf)[0]&0xff) << 24 | \
		       ((buf)[1]&0xff) << 16 | \
		       ((buf)[2]&0xff) <<  8 | \
		       ((buf)[3]&0xff) )

	/* from buffer, char *buf, result to an int */
#define buf_w32(buf) (((buf)[0]&0200) ? (-(~w32(buf)+1)) : w32(buf))


/*
 * oncore_start - initialize data for processing
 */

static int
oncore_start(
	int unit,
	struct peer *peer
	)
{
#define STRING_LEN	32
	register struct instance *instance;
	struct refclockproc *pp;
	int fd1, fd2, num;
	char device1[STRING_LEN], device2[STRING_LEN], Msg[160];
	const char *cp;
	struct stat stat1, stat2;

	/* create instance structure for this unit */

	if (!(instance = (struct instance *) malloc(sizeof *instance))) {
		perror("malloc");
		return (0);
	}
	memset((char *) instance, 0, sizeof *instance);

	/* initialize miscellaneous variables */

	pp = peer->procptr;
	pp->unitptr    = (caddr_t) instance;
	instance->pp   = pp;
	instance->unit = unit;
	instance->peer = peer;
	instance->assert = 1;
	instance->once = 1;

	instance->Bj_day = -1;
	instance->traim = -1;
	instance->traim_in = -1;
	instance->chan_in = -1;
	instance->model = ONCORE_UNKNOWN;
	instance->mode = MODE_UNKNOWN;
	instance->site_survey = ONCORE_SS_UNKNOWN;
	instance->Ag = 0xff;		/* Satellite mask angle, unset by user */
	instance->ant_state = ONCORE_ANTENNA_UNKNOWN;

	peer->precision = -26;
	peer->minpoll = 4;
	peer->maxpoll = 4;
	pp->clockdesc = "Motorola Oncore GPS Receiver";
	memcpy((char *)&pp->refid, "GPS\0", (size_t) 4);

	cp = "ONCORE DRIVER -- CONFIGURING";
	record_clock_stats(&(instance->peer->srcadr), cp);

	instance->o_state = ONCORE_NO_IDEA;
	cp = "state = ONCORE_NO_IDEA";
	record_clock_stats(&(instance->peer->srcadr), cp);

	/* Now open files.
	 * This is a bit complicated, a we dont want to open the same file twice
	 * (its a problem on some OS), and device2 may not exist for the new PPS
	 */

	(void)sprintf(device1, DEVICE1, unit);
	(void)sprintf(device2, DEVICE2, unit);

	/* OPEN DEVICES */
	/* opening different devices for fd1 and fd2 presents no problems */
	/* opening the SAME device twice, seems to be OS dependent.
		(a) on Linux (no streams) no problem
		(b) on SunOS (and possibly Solaris, untested), (streams)
			never see the line discipline.
	   Since things ALWAYS work if we only open the device once, we check
	     to see if the two devices are in fact the same, then proceed to
	     do one open or two.
	*/

	if (stat(device1, &stat1)) {
		sprintf(Msg, "Can't stat fd1 (%s)\n", device1);
		record_clock_stats(&(instance->peer->srcadr), Msg);
		exit(1);
	}

	if (stat(device2, &stat2)) {
		sprintf(Msg, "Can't stat fd2 (%s)\n", device2);
		record_clock_stats(&(instance->peer->srcadr), Msg);
		exit(1);
	}

	if (!(fd1 = refclock_open(device1, SPEED, LDISC_RAW))) {
		sprintf(Msg, "Can't open fd1 (%s)\n", device1);
		record_clock_stats(&(instance->peer->srcadr), Msg);
		exit(1);
	}

	if ((stat1.st_dev == stat2.st_dev) && (stat1.st_ino == stat2.st_ino))	/* same device here */
		fd2 = fd1;
	else {	/* different devices here */
		if ((fd2=open(device2, O_RDWR)) < 0) {
			sprintf(Msg, "Can't open fd2 (%s)\n", device2);
			record_clock_stats(&(instance->peer->srcadr), Msg);
			exit(1);
		}
	}
	num = fd2;

	/* open ppsapi soure */

	if (time_pps_create(num, &instance->pps_h) < 0) {
		record_clock_stats(&(instance->peer->srcadr), "PPSAPI not found in kernel");
		return(0);
	}

	/* continue initialization */

	instance->ttyfd = fd1;
	instance->ppsfd = fd2;

	/* go read any input data in /etc/ntp.oncoreX or /etc/ntp/oncore.X */

	oncore_read_config(instance);

	if (!oncore_ppsapi(instance))
		return(0);

	pp->io.clock_recv = oncore_receive;
	pp->io.srcclock = (caddr_t)peer;
	pp->io.datalen = 0;
	pp->io.fd = fd1;
	if (!io_addclock(&pp->io)) {
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: io_addclock");
		(void) close(fd1);
		free(instance);
		return (0);
	}

#ifdef ONCORE_SHMEM_STATUS
	/*
	 * Before starting ONCORE, lets setup SHMEM
	 * This will include merging an old SHMEM into the new one if
	 * an old one is found.
	 */

	oncore_init_shmem(instance);
#endif

	/*
	 * This will return the Model of the Oncore receiver.
	 * and start the Initialization loop in oncore_msg_Cj.
	 */

	instance->o_state = ONCORE_CHECK_ID;
	cp = "state = ONCORE_CHECK_ID";
	record_clock_stats(&(instance->peer->srcadr), cp);

	instance->timeout = 4;
	oncore_sendmsg(instance->ttyfd, oncore_cmd_Cg, sizeof(oncore_cmd_Cg)); /* Set Posn Fix mode (not Idle (VP)) */
	oncore_sendmsg(instance->ttyfd, oncore_cmd_Cj, sizeof(oncore_cmd_Cj));

	instance->pollcnt = 2;
	return (1);
}


/*
 * oncore_shutdown - shut down the clock
 */

static void
oncore_shutdown(
	int unit,
	struct peer *peer
	)
{
	register struct instance *instance;
	struct refclockproc *pp;

	pp = peer->procptr;
	instance = (struct instance *) pp->unitptr;

	io_closeclock(&pp->io);

	time_pps_destroy (instance->pps_h);

	close(instance->ttyfd);

	if ((instance->ppsfd != -1) && (instance->ppsfd != instance->ttyfd))
		close(instance->ppsfd);

	if (instance->shmemfd)
		close(instance->shmemfd);

	free(instance);
}



/*
 * oncore_poll - called by the transmit procedure
 */

static void
oncore_poll(
	int unit,
	struct peer *peer
	)
{
	struct instance *instance;

	instance = (struct instance *) peer->procptr->unitptr;
	if (instance->timeout) {
		char	*cp;

		instance->timeout--;
		if (instance->timeout == 0) {
			cp = "Oncore: No response from @@Cj, shutting down driver";
			record_clock_stats(&(instance->peer->srcadr), cp);
			oncore_shutdown(unit, peer);
		} else {
			oncore_sendmsg(instance->ttyfd, oncore_cmd_Cj, sizeof(oncore_cmd_Cj));
			cp = "Oncore: Resend @@Cj";
			record_clock_stats(&(instance->peer->srcadr), cp);
		}
		return;
	}

	if (!instance->pollcnt)
		refclock_report(peer, CEVNT_TIMEOUT);
	else
		instance->pollcnt--;
	peer->procptr->polls++;
	instance->polled = 1;
}



/*
 * Initialize PPSAPI
 */

static int
oncore_ppsapi(
	struct instance *instance
	)
{
	int cap, mode, mode1;
	char *cp, Msg[160];

	if (time_pps_getcap(instance->pps_h, &cap) < 0) {
		msyslog(LOG_ERR, "time_pps_getcap failed: %m");
		return (0);
	}

	if (time_pps_getparams(instance->pps_h, &instance->pps_p) < 0) {
		msyslog(LOG_ERR, "time_pps_getparams failed: %m");
		return (0);
	}

	/* nb. only turn things on, if someone else has turned something
	 *	on before we get here, leave it alone!
	 */

	if (instance->assert) {
		cp = "Assert.";
		mode = PPS_CAPTUREASSERT;
		mode1 = PPS_OFFSETASSERT;
	} else {
		cp = "Clear.";
		mode = PPS_CAPTURECLEAR;
		mode1 = PPS_OFFSETCLEAR;
	}
	sprintf(Msg, "Initializing timeing to %s.", cp);
	record_clock_stats(&(instance->peer->srcadr), Msg);

	if (!(mode & cap)) {
		sprintf(Msg, "Can't set timeing to %s, exiting...", cp);
		record_clock_stats(&(instance->peer->srcadr), Msg);
		return(0);
	}

	if (!(mode1 & cap)) {
		sprintf(Msg, "Can't set PPS_%sCLEAR, this will increase jitter.", cp);
		record_clock_stats(&(instance->peer->srcadr), Msg);
		mode1 = 0;
	}

	/* only set what is legal */

	instance->pps_p.mode = (mode | mode1 | PPS_TSFMT_TSPEC) & cap;

	if (time_pps_setparams(instance->pps_h, &instance->pps_p) < 0) {
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: time_pps_setparams fails");
		exit(1);
	}

	/* If HARDPPS is on, we tell kernel */

	if (instance->hardpps) {
		int	i;

		record_clock_stats(&(instance->peer->srcadr), "HARDPPS Set.");

		if (instance->assert)
			i = PPS_CAPTUREASSERT;
		else
			i = PPS_CAPTURECLEAR;

		/* we know that 'i' is legal from above */

		if (time_pps_kcbind(instance->pps_h, PPS_KC_HARDPPS, i,
		    PPS_TSFMT_TSPEC) < 0) {
			msyslog(LOG_ERR, "time_pps_kcbind failed: %m");
			record_clock_stats(&(instance->peer->srcadr), "HARDPPS failed, abort...");
			return (0);
		}
		pps_enable = 1;
	}
	return(1);
}



#ifdef ONCORE_SHMEM_STATUS
static void
oncore_init_shmem(
	struct instance *instance
	)
{
	int i, l, n, fd, shmem_old_size, n1;
	char Msg[160];
	u_char *cp, *cp1, *buf, *shmem_old;
	struct msg_desc *mp;
	struct stat sbuf;
	size_t shmem_length;

       /*
	* The first thing we do is see if there is an instance->shmem_fname file (still)
	* out there from a previous run.  If so, we copy it in and use it to initialize
	* shmem (so we won't lose our almanac if we need it).
	*/

	shmem_old = 0;
	shmem_old_size = 0;
	if ((fd = open(instance->shmem_fname, O_RDONLY)) < 0)
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: Can't open SHMEM file");
	else {
		fstat(fd, &sbuf);
		shmem_old_size = sbuf.st_size;
		if (shmem_old_size != 0) {
			shmem_old = (u_char *) malloc((unsigned) sbuf.st_size);
			if (shmem_old == NULL)
				record_clock_stats(&(instance->peer->srcadr), "ONCORE: Can't malloc buffer for shmem_old");
			else
				read(fd, shmem_old, shmem_old_size);
		}
		close(fd);
	}

	/* OK, we now create the NEW SHMEM. */

	if ((instance->shmemfd = open(instance->shmem_fname, O_RDWR|O_CREAT|O_TRUNC, 0644)) < 0) {
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: Can't open shmem");
		if (shmem_old)
			free(shmem_old);

		return;
	}

	/* see how big it needs to be */

	n = 1;
	for (mp=oncore_messages; mp->flag[0]; mp++) {
		mp->shmem = n;
		/* Allocate space for multiplexed almanac, and 0D/2D/3D @@Ea records */
		if (!strcmp(mp->flag, "Cb")) {
			instance->shmem_Cb = n;
			n += (mp->len + 3) * 34;
		}
		if (!strcmp(mp->flag, "Ba")) {
			instance->shmem_Ba = n;
			n += (mp->len + 3) * 3;
		}
		if (!strcmp(mp->flag, "Ea")) {
			instance->shmem_Ea = n;
			n += (mp->len + 3) * 3;
		}
		if (!strcmp(mp->flag, "Ha")) {
			instance->shmem_Ha = n;
			n += (mp->len + 3) * 3;
		}
		n += (mp->len + 3);
	}
	shmem_length = n + 2;

	buf = malloc(shmem_length);
	if (buf == NULL) {
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: Can't malloc buffer for shmem");
		close(instance->shmemfd);
		if (shmem_old)
			free(shmem_old);

		return;
	}

	memset(buf, 0, shmem_length);

	/* next build the new SHMEM buffer in memory */

	for (mp=oncore_messages; mp->flag[0]; mp++) {
		l = mp->shmem;
		buf[l + 0] = mp->len >> 8;
		buf[l + 1] = mp->len & 0xff;
		buf[l + 2] = 0;
		buf[l + 3] = '@';
		buf[l + 4] = '@';
		buf[l + 5] = mp->flag[0];
		buf[l + 6] = mp->flag[1];
		if (!strcmp(mp->flag, "Cb") || !strcmp(mp->flag, "Ba") || !strcmp(mp->flag, "Ea") || !strcmp(mp->flag, "Ha")) {
			if (!strcmp(mp->flag, "Cb"))
				n = 35;
			else
				n = 4;
			for (i=1; i<n; i++) {
				buf[l + i * (mp->len+3) + 0] = mp->len >> 8;
				buf[l + i * (mp->len+3) + 1] = mp->len & 0xff;
				buf[l + i * (mp->len+3) + 2] = 0;
				buf[l + i * (mp->len+3) + 3] = '@';
				buf[l + i * (mp->len+3) + 4] = '@';
				buf[l + i * (mp->len+3) + 5] = mp->flag[0];
				buf[l + i * (mp->len+3) + 6] = mp->flag[1];
			}
		}
	}

	/* we now walk thru the two buffers (shmem_old and buf, soon to become shmem)
	 * copying the data in shmem_old to buf.
	 * When we are done we write it out and free both buffers.
	 * If the structure sizes dont agree, I will not copy.
	 * This could be due to an addition/deletion or a problem with the disk file.
	 */

	if (shmem_old) {
		if (shmem_old_size == shmem_length) {
			for (cp=buf+4, cp1=shmem_old+4; (n = 256*(*(cp-3)) + *(cp-2));	cp+=(n+3), cp1+=(n+3)) {
				n1 = 256*(*(cp1-3)) + *(cp1-2);
				if (n == 0 || n1 != n || strncmp((char *) cp, (char *) cp1, 4))
					break;

				memcpy(cp, cp1, (size_t) n);
			}
		}
		free(shmem_old);
	}

	i = write(instance->shmemfd, buf, shmem_length);
	free(buf);

	if (i != shmem_length) {
		record_clock_stats(&(instance->peer->srcadr), "ONCORE: error writing shmem");
		close(instance->shmemfd);
		return;
	}

	instance->shmem = (u_char *) mmap(0, shmem_length,
		PROT_READ | PROT_WRITE,
#ifdef MAP_HASSEMAPHORE
		MAP_HASSEMAPHORE |
#endif
		MAP_SHARED, instance->shmemfd, (off_t)0);

	if (instance->shmem == (u_char *)MAP_FAILED) {
		instance->shmem = 0;
		close(instance->shmemfd);
		return;
	}

	sprintf(Msg, "SHMEM (size = %ld) is CONFIGURED and available as %s",
		(u_long) shmem_length, instance->shmem_fname);
	record_clock_stats(&(instance->peer->srcadr), Msg);
}
#endif /* ONCORE_SHMEM_STATUS */



/*
 * Read Input file if it exists.
 */

static void
oncore_read_config(
	struct instance *instance
	)
{
/*
 * First we try to open the configuration file
 *    /etc/oncoreN
 * where N is the unit number viz 127.127.30.N.
 * If we don't find it we try
 *    /etc/ntp.oncore.N
 * and then
 *    /etc/ntp.oncore
 *
 * If we don't find any then we don't have the cable delay or PPS offset
 * and we choose MODE (4) below.
 *
 * Five Choices for MODE
 *    (0) ONCORE is preinitialized, don't do anything to change it.
 *	    nb, DON'T set 0D mode, DON'T set Delay, position...
 *    (1) NO RESET, Read Position, delays from data file, lock it in, go to 0D mode.
 *    (2) NO RESET, Read Delays from data file, do SITE SURVEY to get position,
 *		    lock this in, go to 0D mode.
 *    (3) HARD RESET, Read Position, delays from data file, lock it in, go to 0D mode.
 *    (4) HARD RESET, Read Delays from data file, do SITE SURVEY to get position,
 *		    lock this in, go to 0D mode.
 *     NB. If a POSITION is specified in the config file with mode=(2,4) [SITE SURVEY]
 *	   then this position is set as the INITIAL position of the ONCORE.
 *	   This can reduce the time to first fix.
 * -------------------------------------------------------------------------------
 * Note that an Oncore UT without a battery backup retains NO information if it is
 *   power cycled, with a Battery Backup it remembers the almanac, etc.
 * For an Oncore VP, there is an eeprom that will contain this data, along with the
 *   option of Battery Backup.
 * So a UT without Battery Backup is equivalent to doing a HARD RESET on each
 *   power cycle, since there is nowhere to store the data.
 * -------------------------------------------------------------------------------
 *
 * If we open one or the other of the files, we read it looking for
 *   MODE, LAT, LON, (HT, HTGPS, HTMSL), DELAY, OFFSET, ASSERT, CLEAR, HARDPPS,
 *   STATUS, POSN3D, POSN2D, CHAN, TRAIM
 * then initialize using method MODE.  For Mode = (1,3) all of (LAT, LON, HT) must
 *   be present or mode reverts to (2,4).
 *
 * Read input file.
 *
 *	# is comment to end of line
 *	= allowed between 1st and 2nd fields.
 *
 *	Expect to see one line with 'MODE' as first field, followed by an integer
 *	   in the range 0-4 (default = 4).
 *
 *	Expect to see two lines with 'LONG', 'LAT' followed by 1-3 fields.
 *	All numbers are floating point.
 *		DDD.ddd
 *		DDD  MMM.mmm
 *		DDD  MMM  SSS.sss
 *
 *	Expect to see one line with 'HT' as first field,
 *	   followed by 1-2 fields.  First is a number, the second is 'FT' or 'M'
 *	   for feet or meters.	HT is the height above the GPS ellipsoid.
 *	   If the receiver reports height in both GPS and MSL, then we will report
 *	   the difference GPS-MSL on the clockstats file.
 *
 *	There is an optional line, starting with DELAY, followed
 *	   by 1 or two fields.	The first is a number (a time) the second is
 *	   'MS', 'US' or 'NS' for miliseconds, microseconds or nanoseconds.
 *	    DELAY  is cable delay, typically a few tens of ns.
 *
 *	There is an optional line, starting with OFFSET, followed
 *	   by 1 or two fields.	The first is a number (a time) the second is
 *	   'MS', 'US' or 'NS' for miliseconds, microseconds or nanoseconds.
 *	   OFFSET is the offset of the PPS pulse from 0. (only fully implemented
 *		with the PPSAPI, we need to be able to tell the Kernel about this
 *		offset if the Kernel PLL is in use, but can only do this presently
 *		when using the PPSAPI interface.  If not using the Kernel PLL,
 *		then there is no problem.
 *
 *	There is an optional line, with either ASSERT or CLEAR on it, which
 *	   determine which transition of the PPS signal is used for timing by the
 *	   PPSAPI.  If neither is present, then ASSERT is assumed.
 *	   ASSERT/CLEAR can also be set with FLAG2 of the ntp.conf input.
 *	   For Flag2, ASSERT=0, and hence is default.
 *
 *	There is an optional line, with HARDPPS on it.	Including this line causes
 *	   the PPS signal to control the kernel PLL.
 *	   HARDPPS can also be set with FLAG3 of the ntp.conf input.
 *	   For Flag3, 0 is disabled, and the default.
 *
 *	There are three options that have to do with using the shared memory option.
 *	   First, to enable the option there must be a SHMEM line with a file name.
 *	   The file name is the file associated with the shared memory.
 *
 *	In shared memory, there is one 'record' for each returned variable.
 *	For the @@Ea data there are three 'records' containing position data.
 *	   There will always be data in the record corresponding to the '0D' @@Ea record,
 *	   and the user has a choice of filling the '3D' record by specifying POSN3D,
 *	   or the '2D' record by specifying POSN2D.  In either case the '2D' or '3D'
 *	   record is filled once every 15s.
 *
 *	Two additional variables that can be set are CHAN and TRAIM.  These should be
 *	   set correctly by the code examining the @@Cj record, but we bring them out here
 *	   to allow the user to override either the # of channels, or the existence of TRAIM.
 *	   CHAN expects to be followed by in integer: 6, 8, or 12. TRAIM expects to be
 *	   followed by YES or NO.
 *
 *	There is an optional line with MASK on it followed by one integer field in the
 *	   range 0 to 89. This sets the satellite mask angle and will determine the minimum
 *	   elevation angle for satellites to be tracked by the receiver. The default value
 *	   is 10 deg for the VP and 0 deg for all other receivers.
 *
 * So acceptable input would be
 *	# these are my coordinates (RWC)
 *	LON  -106 34.610
 *	LAT    35 08.999
 *	HT	1589	# could equally well say HT 5215 FT
 *	DELAY  60 ns
 */

	FILE	*fd;
	char	*cp, *cc, *ca, line[100], units[2], device[20], Msg[160], **cpp;
	char	*dirs[] = { "/etc/ntp", "/etc", 0 };
	int	i, sign, lat_flg, long_flg, ht_flg, mode, mask;
	double	f1, f2, f3;

	fd = NULL;	/* just to shutup gcc complaint */
	for (cpp=dirs; *cpp; cpp++) {
		cp = *cpp;
		sprintf(device, "%s/ntp.oncore.%d", cp, instance->unit); /* try "ntp.oncore.0 */
		if ((fd=fopen(device, "r")))
			break;
		sprintf(device, "%s/ntp.oncore%d", cp, instance->unit);  /* try "ntp.oncore0" */
		if ((fd=fopen(device, "r")))
			break;
		sprintf(device, "%s/ntp.oncore", cp);   /* and finally "ntp.oncore" */
		if ((fd=fopen(device, "r")))
			break;
	}

	if (!fd) {	/* no inputfile, default to the works ... */
		instance->init_type = 4;
		return;
	}

	mode = mask = 0;
	lat_flg = long_flg = ht_flg = 0;
	while (fgets(line, 100, fd)) {

		/* Remove comments */
		if ((cp = strchr(line, '#')))
			*cp = '\0';

		/* Remove trailing space */
		for (i = strlen(line);
		     i > 0 && isascii((int)line[i - 1]) && isspace((int)line[i - 1]);
			)
			line[--i] = '\0';

		/* Remove leading space */
		for (cc = line; *cc && isascii((int)*cc) && isspace((int)*cc); cc++)
			continue;

		/* Stop if nothing left */
		if (!*cc)
			continue;

		/* Uppercase the command and find the arg */
		for (ca = cc; *ca; ca++) {
			if (isascii((int)*ca)) {
				if (islower((int)*ca)) {
					*ca = toupper(*ca);
				} else if (isspace((int)*ca) || (*ca == '='))
					break;
			}
		}

		/* Remove space (and possible =) leading the arg */
		for (; *ca && isascii((int)*ca) && (isspace((int)*ca) || (*ca == '=')); ca++)
			continue;

		if (!strncmp(cc, "STATUS", (size_t) 6) || !strncmp(cc, "SHMEM", (size_t) 5)) {
			i = strlen(ca);
			instance->shmem_fname = (char *) malloc((unsigned) (i+1));
			strcpy(instance->shmem_fname, ca);
			continue;
		}

		/* Uppercase argument as well */
		for (cp = ca; *cp; cp++)
			if (isascii((int)*cp) && islower((int)*cp))
				*cp = toupper(*cp);

		if (!strncmp(cc, "LAT", (size_t) 3)) {
			f1 = f2 = f3 = 0;
			sscanf(ca, "%lf %lf %lf", &f1, &f2, &f3);
			sign = 1;
			if (f1 < 0) {
				f1 = -f1;
				sign = -1;
			}
			instance->ss_lat = sign*1000*(fabs(f3) + 60*(fabs(f2) + 60*f1)); /*miliseconds*/
			lat_flg++;
		} else if (!strncmp(cc, "LON", (size_t) 3)) {
			f1 = f2 = f3 = 0;
			sscanf(ca, "%lf %lf %lf", &f1, &f2, &f3);
			sign = 1;
			if (f1 < 0) {
				f1 = -f1;
				sign = -1;
			}
			instance->ss_long = sign*1000*(fabs(f3) + 60*(fabs(f2) + 60*f1)); /*miliseconds*/
			long_flg++;
		} else if (!strncmp(cc, "HT", (size_t) 2)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'F')
				f1 = 0.3048 * f1;
			instance->ss_ht = 100 * f1;    /* cm */
			ht_flg++;
		} else if (!strncmp(cc, "DELAY", (size_t) 5)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'N')
				;
			else if (units[0] == 'U')
				f1 = 1000 * f1;
			else if (units[0] == 'M')
				f1 = 1000000 * f1;
			else
				f1 = 1000000000 * f1;
			if (f1 < 0 || f1 > 1.e9)
				f1 = 0;
			if (f1 < 0 || f1 > 999999) {
				sprintf(Msg, "PPS Cable delay of %fns out of Range, ignored", f1);
				record_clock_stats(&(instance->peer->srcadr), Msg);
			} else
				instance->delay = f1;		/* delay in ns */
		} else if (!strncmp(cc, "OFFSET", (size_t) 6)) {
			f1 = 0;
			units[0] = '\0';
			sscanf(ca, "%lf %1s", &f1, units);
			if (units[0] == 'N')
				;
			else if (units[0] == 'U')
				f1 = 1000 * f1;
			else if (units[0] == 'M')
				f1 = 1000000 * f1;
			else
				f1 = 1000000000 * f1;
			if (f1 < 0 || f1 > 1.e9)
				f1 = 0;
			if (f1 < 0 || f1 > 999999999.) {
				sprintf(Msg, "PPS Offset of %fns out of Range, ignored", f1);
				record_clock_stats(&(instance->peer->srcadr), Msg);
			} else
				instance->offset = f1;		/* offset in ns */
		} else if (!strncmp(cc, "MODE", (size_t) 4)) {
			sscanf(ca, "%d", &mode);
			if (mode < 0 || mode > 4)
				mode = 4;
		} else if (!strncmp(cc, "ASSERT", (size_t) 6)) {
			instance->assert = 1;
		} else if (!strncmp(cc, "CLEAR", (size_t) 5)) {
			instance->assert = 0;
		} else if (!strncmp(cc, "HARDPPS", (size_t) 7)) {
			instance->hardpps = 1;
		} else if (!strncmp(cc, "POSN2D", (size_t) 6)) {
			instance->shmem_Posn = 2;
		} else if (!strncmp(cc, "POSN3D", (size_t) 6)) {
			instance->shmem_Posn = 3;
		} else if (!strncmp(cc, "CHAN", (size_t) 4)) {
			sscanf(ca, "%d", &i);
			if ((i == 6) || (i == 8) || (i == 12))
				instance->chan_in = i;
		} else if (!strncmp(cc, "TRAIM", (size_t) 5)) {
			instance->traim_in = 1; 	/* so TRAIM alone is YES */
			if (!strcmp(ca, "NO") || !strcmp(ca, "OFF"))    /* Yes/No, On/Off */
				instance->traim_in = 0;
		} else if (!strncmp(cc, "MASK", (size_t) 4)) {
			sscanf(ca, "%d", &mask);
			if (mask > -1 && mask < 90)
				instance->Ag = mask;			/* Satellite mask angle */
		}
	}
	fclose(fd);

	/*
	 *    OK, have read all of data file, and extracted the good stuff.
	 *    If lat/long/ht specified they ALL must be specified for mode = (1,3).
	 */

	instance->posn_set = 1;
	if (!( lat_flg && long_flg && ht_flg )) {
		printf("ONCORE: incomplete data on %s\n", device);
		instance->posn_set = 0;
		if (mode == 1 || mode == 3) {
			sprintf(Msg, "Input Mode = %d, but no/incomplete position, mode set to %d", mode, mode+1);
			record_clock_stats(&(instance->peer->srcadr), Msg);
			mode++;
		}
	}
	instance->init_type = mode;

	sprintf(Msg, "Input mode = %d", mode);
	record_clock_stats(&(instance->peer->srcadr), Msg);
}



/*
 * move data from NTP to buffer (toss the extra in the unlikely case it won't fit)
 */

static void
oncore_receive(
	struct recvbuf *rbufp
	)
{
	size_t i;
	u_char *p;
	struct peer *peer;
	struct instance *instance;

	peer = (struct peer *)rbufp->recv_srcclock;
	instance = (struct instance *) peer->procptr->unitptr;
	p = (u_char *) &rbufp->recv_space;

#if 0
	if (debug > 4) {
		int i;
		printf("ONCORE: >>>");
		for(i=0; i<rbufp->recv_length; i++)
			printf("%02x ", p[i]);
		printf("\n");
		printf("ONCORE: >>>");
		for(i=0; i<rbufp->recv_length; i++)
			printf("%03o ", p[i]);
		printf("\n");
	}
#endif

	i = rbufp->recv_length;
	if (rcvbuf+rcvptr+i > &rcvbuf[sizeof rcvbuf])
		i = sizeof(rcvbuf) - rcvptr;	/* and some char will be lost */
	memcpy(rcvbuf+rcvptr, p, i);
	rcvptr += i;
	oncore_consume(instance);
}



/*
 * Deal with any complete messages
 */

static void
oncore_consume(
	struct instance *instance
	)
{
	int i, m;
	unsigned l;

	while (rcvptr >= 7) {
		if (rcvbuf[0] != '@' || rcvbuf[1] != '@') {
			/* We're not in sync, lets try to get there */
			for (i=1; i < rcvptr-1; i++)
				if (rcvbuf[i] == '@' && rcvbuf[i+1] == '@')
					break;
#ifdef DEBUG
			if (debug > 4)
				printf("ONCORE[%d]: >>> skipping %d chars\n", instance->unit, i);
#endif
			if (i != rcvptr)
				memcpy(rcvbuf, rcvbuf+i, (size_t)(rcvptr-i));
			rcvptr -= i;
			continue;
		}

		/* Ok, we have a header now */
		l = sizeof(oncore_messages)/sizeof(oncore_messages[0]) -1;
		for(m=0; m<l; m++)
			if (!strncmp(oncore_messages[m].flag, (char *)(rcvbuf+2), (size_t) 2))
				break;
		if (m == l) {
#ifdef DEBUG
			if (debug > 4)
				printf("ONCORE[%d]: >>> Unknown MSG, skipping 4 (%c%c)\n", instance->unit, rcvbuf[2], rcvbuf[3]);
#endif
			memcpy(rcvbuf, rcvbuf+4, (size_t) 4);
			rcvptr -= 4;
			continue;
		}

		l = oncore_messages[m].len;
#if 0
		if (debug > 3)
			printf("ONCORE[%d]: GOT: %c%c  %d of %d entry %d\n", instance->unit, rcvbuf[2], rcvbuf[3], rcvptr, l, m);
#endif
		/* Got the entire message ? */

		if (rcvptr < l)
			return;

		/* are we at the end of message? should be <Cksum><CR><LF> */

		if (rcvbuf[l-2] != '\r' || rcvbuf[l-1] != '\n') {
#ifdef DEBUG
			if (debug)
				printf("ONCORE[%d]: NO <CR><LF> at end of message\n", instance->unit);
#endif
		} else {	/* check the CheckSum */
			if (oncore_checksum_ok(rcvbuf, l)) {
				if (instance->shmem != NULL) {
					instance->shmem[oncore_messages[m].shmem + 2]++;
					memcpy(instance->shmem + oncore_messages[m].shmem + 3,
					    rcvbuf, (size_t) l);
				}
				oncore_msg_any(instance, rcvbuf, (size_t) (l-3), m);
				if (oncore_messages[m].handler)
					oncore_messages[m].handler(instance, rcvbuf, (size_t) (l-3));
			}
#ifdef DEBUG
			else if (debug) {
				printf("ONCORE[%d]: Checksum mismatch!\n", instance->unit);
				printf("ONCORE[%d]: @@%c%c ", instance->unit, rcvbuf[2], rcvbuf[3]);
				for (i=4; i<l; i++)
					printf("%03o ", rcvbuf[i]);
				printf("\n");
			}
#endif
		}

		if (l != rcvptr)
			memcpy(rcvbuf, rcvbuf+l, (size_t) (rcvptr-l));
		rcvptr -= l;
	}
}



static void
oncore_get_timestamp(
	struct instance *instance,
	long dt1,	/* tick offset THIS time step */
	long dt2	/* tick offset NEXT time step */
	)
{
	int	Rsm;
	u_long	j;
	l_fp ts, ts_tmp;
	double dmy;
#ifdef HAVE_STRUCT_TIMESPEC
	struct timespec *tsp = 0;
#else
	struct timeval	*tsp = 0;
#endif
	int	current_mode;
	u_long	i;
	pps_params_t current_params;
	struct timespec timeout;
	pps_info_t pps_i;

#if 1
	/* If we are in SiteSurvey mode, then we are in 3D mode, and we fall thru.
	 * If we have Finished the SiteSurvey, then we fall thru for the 14/15
	 *  times we get here in 0D mode (the 1/15 is in 3D for SHMEM).
	 * This gives good time, which gets better when the SS is done.
	 */

	if ((instance->site_survey == ONCORE_SS_DONE) && (instance->mode != MODE_0D))
#else
	/* old check, only fall thru for SS_DONE and 0D mode, 2h45m wait for ticks */

	if ((instance->site_survey != ONCORE_SS_DONE) || (instance->mode != MODE_0D))
#endif
		return;

	/* Don't do anything without an almanac to define the GPS->UTC delta */

	if (instance->rsm.bad_almanac)
		return;

	/* Once the Almanac is valid, the M12+T does not produce valid UTC
	 * immediately.
	 * Wait for UTC offset decode valid, then wait one message more
	 * so we are not off by 13 seconds after  reset.
	 */

	if (instance->count5) {
		instance->count5--;
		return;
	}

	j = instance->ev_serial;
	timeout.tv_sec = 0;
	timeout.tv_ns…