Split RTCM parsing into its own module.

1 files changed, 0 insertions, 259 deletions

diff --git a/rtcmdecode.c b/rtcmdecode.c
index a3aa6476..a9208722 100644
--- a/rtcmdecode.c
+++ b/rtcmdecode.c
@@ -6,264 +6,6 @@
 #include "rtcm.h"
 #include "gpsd.h"
 
-/* ################ */
-
-#define MAG_SHIFT 6u
-#define MAG_TAG_DATA (1 << MAG_SHIFT)
-#define MAG_TAG_MASK (3 << MAG_SHIFT)
-
-#define PREAMBLE_PATTERN 0x66
-#define PREAMBLE_SHIFT 22
-#define PREAMBLE_MASK (0xFF << PREAMBLE_SHIFT)
-
-#define W_DATA_MASK	0x3fffffc0u
-
-/*@ +charint @*/
-static unsigned char   parity_array[] = {
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
-    0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0
-};
-
-static unsigned int reverse_bits[] = {
-    0, 32, 16, 48, 8, 40, 24, 56, 4, 36, 20, 52, 12, 44, 28, 60,
-    2, 34, 18, 50, 10, 42, 26, 58, 6, 38, 22, 54, 14, 46, 30, 62,
-    1, 33, 17, 49, 9, 41, 25, 57, 5, 37, 21, 53, 13, 45, 29, 61,
-    3, 35, 19, 51, 11, 43, 27, 59, 7, 39, 23, 55, 15, 47, 31, 63
-};
-/*@ -charint @*/
-
-static unsigned int rtcmparity(RTCMWORD th)
-{
-#define P_30_MASK	0x40000000u
-
-#define	PARITY_25	0xbb1f3480u
-#define	PARITY_26	0x5d8f9a40u
-#define	PARITY_27	0xaec7cd00u
-#define	PARITY_28	0x5763e680u
-#define	PARITY_29	0x6bb1f340u
-#define	PARITY_30	0x8b7a89c0u
-    RTCMWORD        t;
-    unsigned int    p;
-
-    /*
-    if (th & P_30_MASK)
-	th ^= W_DATA_MASK;
-    */
-
-    /*@ +charint @*/
-    t = th & PARITY_25;
-    p = parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-	parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff];
-    t = th & PARITY_26;
-    p = (p << 1) | (parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-		  parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff]);
-    t = th & PARITY_27;
-    p = (p << 1) | (parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-		  parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff]);
-    t = th & PARITY_28;
-    p = (p << 1) | (parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-		  parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff]);
-    t = th & PARITY_29;
-    p = (p << 1) | (parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-		  parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff]);
-    t = th & PARITY_30;
-    p = (p << 1) | (parity_array[t & 0xff] ^ parity_array[(t >> 8) & 0xff] ^
-		  parity_array[(t >> 16) & 0xff] ^ parity_array[(t >> 24) & 0xff]);
-    /*@ -charint @*/
-
-    gpsd_report(6, "parity %u\n", p);
-    return (p);
-}
-
-
-#define rtcmparityok(w)	(rtcmparity(w) == ((w) & 0x3f))
-
-#if 0
-/* 
- * Defining the above as a function triggers an optimizer bug in gcc 3.4.2.
- * The symptom is that parity computation is screwed up and the decoder
- * never achieves sync lock.  Something steps on the argument to 
- * rtcmparity(); the lossage appears to be related to the compiler's 
- * attempt to fold the rtcmparity() call into rtcmparityok() in some
- * tail-recursion-like manner.  This happens under -O2, but not -O1, on
- * both i386 and amd64. gcc 4.0 does not manifest the bug.
- */
-static bool rtcmparityok(RTCMWORD w)
-{
-    return (rtcmparity(w) == (w & 0x3f));
-}
-#endif
-
-void rtcm_init(/*@out@*/struct rtcm_ctx * ctx)
-{
-    ctx->curr_word = 0;
-    ctx->curr_offset = 24;	/* first word */
-    ctx->locked = false;
-    ctx->bufindex = 0;
-}
-
-/*@ -usereleased -compdef @*/
-/*@null@*/ struct rtcm_msghdr *rtcm_decode(struct rtcm_ctx * ctx, unsigned int c)
-{
-    struct rtcm_msghdr *res;
-
-    if ((c & MAG_TAG_MASK) != MAG_TAG_DATA) {
-	return RTCM_NO_SYNC;
-    }
-    c = reverse_bits[c & 0x3f];
-
-    /*@ -shiftnegative @*/
-    if (!ctx->locked) {
-	ctx->curr_offset = -5;
-	ctx->bufindex = 0;
-
-	while (ctx->curr_offset <= 0) {
-	    gpsd_report(7, "syncing");
-	    ctx->curr_word <<= 1;
-	    if (ctx->curr_offset > 0) {
-		ctx->curr_word |= c << ctx->curr_offset;
-	    } else {
-		ctx->curr_word |= c >> -(ctx->curr_offset);
-	    }
-	    if (((struct rtcm_msghw1 *) & ctx->curr_word)->preamble ==
-		PREAMBLE_PATTERN) {
-		if (rtcmparityok(ctx->curr_word)) {
-		    gpsd_report(5, "preamble ok, parity ok -- locked\n");
-		    ctx->locked = true;
-		    /* ctx->curr_offset;  XXX - testing */
-		    break;
-		}
-		gpsd_report(5, "preamble ok, parity fail\n");
-	    }
-	    ctx->curr_offset++;
-	}			/* end while */
-    }
-    if (ctx->locked) {
-	res = RTCM_SYNC;
-
-	if (ctx->curr_offset > 0) {
-	    ctx->curr_word |= c << ctx->curr_offset;
-	} else {
-	    ctx->curr_word |= c >> -(ctx->curr_offset);
-	}
-
-	if (ctx->curr_offset <= 0) {
-	    /* weird-assed inversion */
-	    if (ctx->curr_word & P_30_MASK)
-		ctx->curr_word ^= W_DATA_MASK;
-
-	    if (rtcmparityok(ctx->curr_word)) {
-		if (((struct rtcm_msghw1 *) & ctx->curr_word)->preamble ==
-		    PREAMBLE_PATTERN) {
-		    gpsd_report(6, 
-				"Preamble spotted (index: %u)",
-				ctx->bufindex);
-		    ctx->bufindex = 0;
-		}
-		gpsd_report(6,
-			    "processing word %u (offset %d)\n",
-			    ctx->bufindex, ctx->curr_offset);
-		{
-		    struct rtcm_msghdr  *msghdr = (struct rtcm_msghdr *) ctx->buf;
-
-		    /*
-		     * Guard against a buffer overflow attack.  Just wait for
-		     * the next PREAMBLE_PATTERN and go on from there. 
-		     */
-		    if (ctx->bufindex >= RTCM_CTX_MAX_MSGSZ){
-			ctx->bufindex = 0;
-			return RTCM_NO_SYNC;
-		    }
-
-		    ctx->buf[ctx->bufindex] = ctx->curr_word;
-
-		    if ((ctx->bufindex == 0) &&
-			(msghdr->w1.preamble != PREAMBLE_PATTERN)) {
-			gpsd_report(6, "word 0 not a preamble- punting\n");
-			return RTCM_NO_SYNC;
-		    }
-		    ctx->bufindex++;
-		    /* rtcm_print_msg(msghdr); */
-
-		    if (ctx->bufindex > 2) {	/* do we have the length yet? */
-			if (ctx->bufindex >= msghdr->w2.frmlen + 2) {
-			    res = msghdr;
-			    ctx->bufindex = 0;
-			}
-		    }
-		}
-		ctx->curr_word <<= 30;	/* preserve the 2 low bits */
-		ctx->curr_offset += 30;
-		if (ctx->curr_offset > 0) {
-		    ctx->curr_word |= c << ctx->curr_offset;
-		} else {
-		    ctx->curr_word |= c >> -(ctx->curr_offset);
-		}
-	    } else {
-		gpsd_report(5, "Parity failure, lost lock\n");
-		ctx->locked = false;
-	    }
-	}
-	ctx->curr_offset -= 6;
-	gpsd_report(7, "residual %d", ctx->curr_offset);
-	return res;
-    }
-    /*@ +shiftnegative @*/
-
-    /* never achieved lock */
-    return RTCM_NO_SYNC;
-}
-/*@ +usereleased +compdef @*/
-
-#ifdef __UNUSED__
-void rtcm_output_mag(RTCMWORD * ip)
-/* ship an RTCM message to standard output in Magnavox format */
-{
-    static RTCMWORD w = 0;
-    int             len;
-    static uint     sqnum = 0;
-
-    len = ((struct rtcm_msghdr *) ip)->w2.frmlen + 2;
-    ((struct rtcm_msghdr *) ip)->w2.sqnum = sqnum++;
-    sqnum &= 0x7;
-
-    while (len-- > 0) {
-	w <<= 30;
-	w |= *ip++ & W_DATA_MASK;
-
-	w |= rtcmparity(w);
-
-	/* weird-assed inversion */
-	if (w & P_30_MASK)
-	    w ^= W_DATA_MASK;
-
-	/* msb first */
-	putchar(MAG_TAG_DATA | reverse_bits[(w >> 24) & 0x3f]);
-	putchar(MAG_TAG_DATA | reverse_bits[(w >> 18) & 0x3f]);
-	putchar(MAG_TAG_DATA | reverse_bits[(w >> 12) & 0x3f]);
-	putchar(MAG_TAG_DATA | reverse_bits[(w >> 6) & 0x3f]);
-	putchar(MAG_TAG_DATA | reverse_bits[(w) & 0x3f]);
-    }
-}
-#endif /* UNUSED */
-
-/* ################ */
-
-#ifdef TESTMAIN
 #include <stdio.h>
 #include <stdarg.h>
 
@@ -375,6 +117,5 @@ int main(int argc, char **argv)
     }
     exit(0);
 }
-#endif /* TESTMAIN */
 
 /* end */