Merge branch 'master' of https://github.com/ismagom/libLTE

lte/include/lte/fec/crc.h

@@ -36,7 +36,30 @@
 #define LTE_CRC8	0x19B
 
 
-unsigned int crc(unsigned int crc, char *bufptr, int len,
-		int long_crc,unsigned int poly, int paste_word);
+#define _WITHMALLOC
+
+#ifndef _WITHMALLOC
+#define MAX_LENGTH	1024*16
+#endif
+
+typedef struct {
+	unsigned long table[256];
+#ifdef _WITHMALLOC
+	unsigned char *data0;
+#else
+	unsigned char data0[MAX_LENGTH];
+#endif
+	int polynom;
+	int order;
+	unsigned long crcinit; 
+	unsigned long crcxor; 
+	unsigned long crcmask;
+	unsigned long crchighbit;
+	unsigned int crc_out;
+} crc_t;
+
+
+int crc_init(crc_t *crc_par);
+unsigned int crc_attach(char *bufptr, int len, crc_t *crc_params);
 
 #endif

lte/lib/fec/src/crc.c

@@ -28,63 +28,129 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include "lte/utils/pack.h"
 
-unsigned int cword;
+#include "lte/fec/crc.h"
 
-unsigned int icrc1(unsigned int crc, unsigned short onech,int long_crc,
-		int left_shift,unsigned int poly)
-{
-  int i;
-  unsigned int tmp=(unsigned int) (crc ^ (onech << (long_crc >> 1) ));
 
-  for (i=0;i<left_shift;i++) {
-    if (tmp & (0x1<<(long_crc-1)))
-      tmp=(tmp<<1)^poly;
-    else
-      tmp <<= 1;
-  }
+void gen_crc_table(crc_t *crc_params) {
+
+	int i, j, ord=(crc_params->order-8);
+	unsigned long bit, crc;
 
-  return tmp;
+	for (i=0; i<256; i++) {
+		crc = ((unsigned long)i)<<ord;
+		for (j=0; j<8; j++) {
+			bit = crc & crc_params->crchighbit;
+			crc<<= 1;
+			if (bit) crc^= crc_params->polynom;
+		}			
+		crc_params->table[i]=crc & crc_params->crcmask;
+	}
 }
 
-unsigned int crc(unsigned int crc, char *bufptr, int len,
-		int long_crc,unsigned int poly, int paste_word) {
-
-  int i,k;
-  unsigned int data;
-  int stop;
-  unsigned int ret;
-
-  cword=crc;
-
-  k=0;
-  stop=0;
-  while(!stop) {
-    data=0;
-    for (i=0;i<long_crc/2;i++) {
-      if (bufptr[k] && k<len)
-        data|=(0x1<<(long_crc/2-1-i));
-      k++;
-      if (k==len) {
-        stop=1;
-        i++;
-        break;
+
+unsigned long  crctable (unsigned long length, crc_t *crc_params) {
+
+	// Polynom order 8, 16, 24 or 32 only.
+	int ord=crc_params->order-8;
+	unsigned long crc = crc_params->crcinit;
+	unsigned char* data = crc_params->data0;
+
+	while (length--){
+		 crc = (crc << 8) ^ crc_params->table[ ((crc >> (ord)) & 0xff) ^ *data++];
 	}
+	return((crc ^ crc_params->crcxor) & crc_params->crcmask);
+}
+
+unsigned long reversecrcbit(unsigned int crc, int nbits, crc_t *crc_params) {
+
+	unsigned long m, rmask=0x1;
+
+	for(m=0; m<nbits; m++){	
+		if((rmask & crc) == 0x01 )crc = (crc ^ crc_params->polynom)>>1;
+		else crc = crc >> 1;
 	}
+	return((crc ^ crc_params->crcxor) & crc_params->crcmask);
+}
+
+
+int crc_init(crc_t *crc_par){
 
-    cword=(unsigned int) (icrc1((unsigned int) (cword<<long_crc>>long_crc),
-    		data,long_crc,i,poly)<<long_crc)>>long_crc;
+	// Compute bit masks for whole CRC and CRC high bit
+	crc_par->crcmask = ((((unsigned long)1<<(crc_par->order-1))-1)<<1)|1;
+	crc_par->crchighbit = (unsigned long)1<<(crc_par->order-1);
+
+	printf("crcmask=%x, crchightbit=%x\n", 
+			(unsigned int)crc_par->crcmask, (unsigned int)crc_par->crchighbit);
+
+	// check parameters
+	if (crc_par->order%8 != 0) {
+		printf("ERROR, invalid order=%d, it must be 8, 16, 24 or 32.\n", crc_par->order);
+		return(0);
 	}
 
-  ret=cword;
-  if (paste_word) {
-    cword<<=32-long_crc;
-    for (i=0;i<long_crc;i++) {
-       bufptr[i+len]=((cword&(0x1<<31))>>31);
-       cword<<=1;
+	if (crc_par->crcinit != (crc_par->crcinit & crc_par->crcmask)) {
+		printf("ERROR, invalid crcinit.\n");
+		return(0);
 	}
+	if (crc_par->crcxor != (crc_par->crcxor & crc_par->crcmask)) {
+		printf("ERROR, invalid crcxor.\n");
+		return(0);
 	}
-  return (ret);
+	// generate lookup table
+	gen_crc_table(crc_par);
+
+	return(1);
 }
 
 
+unsigned int crc_attach(char *bufptr, int len, crc_t *crc_params) {
+
+	int i, len8, res8, a;
+	unsigned int crc;
+	char *pter;
+
+#ifdef _WITHMALLOC
+	crc_params->data0 = (unsigned char *)malloc(sizeof(*crc_params->data0) * (len+crc_params->order)*2);
+	if (!crc_params->data0) {
+		perror("malloc ERROR: Allocating memory for data pointer in crc() function");
+		return(-1);
+	}
+#else
+	if((((len+crc_params->order)>>3) + 1) > MAX_LENGTH){
+		printf("ERROR: Not enough memory allocated\n");
+		return(-1);
+	}
+#endif
+	//# Pack bits into bytes 
+	len8=(len>>3);
+	res8=8-(len - (len8<<3));
+	if(res8>0)a=1;
+	else a=0;
+
+	// Zeroed additional bits
+	memset((char *)(bufptr+len),0,(32)*sizeof(char));
+
+	for(i=0; i<len8+a; i++){
+		pter=(char *)(bufptr+8*i);
+		crc_params->data0[i]=(unsigned char)(unpack_bits(&pter, 8)&0xFF);
+	}
+	// Calculate CRC
+	crc=crctable(len8+a, crc_params);
+
+	// Reverse CRC res8 positions
+	if(a==1)crc=reversecrcbit(crc, res8, crc_params);
+
+	// Add CRC
+	pter=(char *)(bufptr+len);
+	pack_bits(crc, &pter, crc_params->order);
+
+#ifdef _WITHMALLOC
+	free(crc_params->data0);
+	crc_params->data0=NULL;
+#endif
+	//Return CRC value
+	return crc;
+}

lte/lib/fec/test/CMakeLists.txt

@@ -55,9 +55,9 @@ ADD_TEST(viterbi_1000_4 viterbi_test -n 100 -s 1 -l 1000 -k 7 -t -e 4.5)
 ADD_EXECUTABLE(crc_test crc_test.c)
 TARGET_LINK_LIBRARIES(crc_test lte)
 
-ADD_TEST(crc_24A crc_test -n 5000 -l 24 -p 0x1864CFB -s 1)
-ADD_TEST(crc_24B crc_test -n 5000 -l 24 -p 0x1800063 -s 1)
-ADD_TEST(crc_16 crc_test -n 5000 -l 16 -p 0x11021 -s 1)
-ADD_TEST(crc_8 crc_test -n 5000 -l 8 -p 0x19B -s 1)
+ADD_TEST(crc_24A crc_test -n 5001 -l 24 -p 0x1864CFB -s 1)
+ADD_TEST(crc_24B crc_test -n 5001 -l 24 -p 0x1800063 -s 1)
+ADD_TEST(crc_16 crc_test -n 5001 -l 16 -p 0x11021 -s 1)
+ADD_TEST(crc_8 crc_test -n 5001 -l 8 -p 0x19B -s 1)
 
  

lte/lib/fec/test/crc_test.c

@@ -35,12 +35,11 @@
 #include <time.h>
 
 #include "lte.h"
-
 #include "crc_test.h"
 
-int num_bits = 1000, crc_length = 16;
-unsigned int crc_poly = 0x11021;
-unsigned int seed = 0;
+int num_bits = 5000, crc_length = 24;
+unsigned int crc_poly = 0x1864CFB;
+unsigned int seed = 1;
 
 
 void usage(char *prog) {
@@ -78,10 +77,11 @@ int main(int argc, char **argv) {
 	int i;
 	char *data;
 	unsigned int crc_word, expected_word;
+	crc_t crc_p;
 
 	parse_args(argc, argv);
 
-	data = malloc(sizeof(char) * (num_bits+crc_length));
+	data = malloc(sizeof(char) * (num_bits+crc_length)*2);
 	if (!data) {
 		perror("malloc");
 		exit(-1);
@@ -97,19 +97,24 @@ int main(int argc, char **argv) {
 		data[i] = rand()%2;
 	}
 
+	//Initialize CRC params and tables
+	crc_p.polynom=crc_poly;
+	crc_p.order=crc_length;
+	crc_p.crcinit=0x00000000; 
+	crc_p.crcxor=0x00000000;
+	if(!crc_init(&crc_p))exit(0);
+
 	// generate CRC word
-	crc_word = crc(0, data, num_bits, crc_length, crc_poly, 1);
+	crc_word = crc_attach(data, num_bits, &crc_p);
 
 	// check if result is zero
-	if (crc(0, data, num_bits + crc_length, crc_length, crc_poly, 0)) {
+	if (crc_attach(data, num_bits + crc_length, &crc_p)) {
 		printf("CRC check is non-zero\n");
 		exit(-1);
 	}
 
 	free(data);
 
-	printf("CRC word: 0x%x\n", crc_word);
-
 	// check if generated word is as expected
 	if (get_expected_word(num_bits, crc_length, crc_poly, seed, &expected_word)) {
 		fprintf(stderr, "Test parameters not defined in test_results.h\n");

lte/lib/fec/test/crc_test.h

@@ -39,10 +39,11 @@ typedef struct {
 
 
 static expected_word_t expected_words[] = {
-		{5000, 24, LTE_CRC24A, 1, 0x4D0836},		// LTE CRC24A (36.212 Sec 5.1.1)
-		{5000, 24, LTE_CRC24B, 1, 0x9B68F8},		// LTE CRC24B
-		{5000, 16, LTE_CRC16, 1, 0xBFFA},  		// LTE CRC16
-		{5000, 8, LTE_CRC8, 1, 0xF8},				// LTE CRC8
+
+		{5001, 24, LTE_CRC24A, 1, 0x1C5C97},		// LTE CRC24A (36.212 Sec 5.1.1)
+		{5001, 24, LTE_CRC24B, 1, 0x36D1F0},		// LTE CRC24B
+		{5001, 16, LTE_CRC16, 1, 0x7FF4},  		// LTE CRC16: 0x7FF4
+		{5001, 8, LTE_CRC8, 1,  0xF0},			// LTE CRC8 0xF8
 
 		{-1, -1, 0, 0, 0}
 };