--- /dev/null
+#include "canframelen.h"
+#include <stdint.h>
+#include <stddef.h>
+#include <stdbool.h>
+#include <string.h>
+#include <assert.h>
+#include <stdio.h> /* FIXME: remove me */
+
+static void sprint_canframe(char *buf , struct can_frame *cf, int sep) {
+ /* documentation see lib.h */
+
+ int i,offset;
+ int dlc = (cf->can_dlc > 8)? 8 : cf->can_dlc;
+
+ if (cf->can_id & CAN_ERR_FLAG) {
+ sprintf(buf, "%08X#", cf->can_id & (CAN_ERR_MASK|CAN_ERR_FLAG));
+ offset = 9;
+ } else if (cf->can_id & CAN_EFF_FLAG) {
+ sprintf(buf, "%08X#", cf->can_id & CAN_EFF_MASK);
+ offset = 9;
+ } else {
+ sprintf(buf, "%03X#", cf->can_id & CAN_SFF_MASK);
+ offset = 4;
+ }
+
+ if (cf->can_id & CAN_RTR_FLAG) /* there are no ERR frames with RTR */
+ sprintf(buf+offset, "R");
+ else
+ for (i = 0; i < dlc; i++) {
+ sprintf(buf+offset, "%02X", cf->data[i]);
+ offset += 2;
+ if (sep && (i+1 < dlc))
+ sprintf(buf+offset++, ".");
+ }
+}
+
+/**
+ * Functions and types for CRC checks.
+ *
+ * Generated on Wed Jan 8 15:14:20 2014,
+ * by pycrc v0.8.1, http://www.tty1.net/pycrc/
+ * using the configuration:
+ * Width = 15
+ * Poly = 0x4599
+ * XorIn = 0x0000
+ * ReflectIn = False
+ * XorOut = 0x0000
+ * ReflectOut = False
+ * Algorithm = table-driven
+ *****************************************************************************/
+
+typedef uint16_t crc_t;
+
+/**
+ * Static table used for the table_driven implementation.
+ *****************************************************************************/
+static const crc_t crc_table[256] = {
+ 0x0000, 0x4599, 0x4eab, 0x0b32, 0x58cf, 0x1d56, 0x1664, 0x53fd, 0x7407, 0x319e, 0x3aac, 0x7f35, 0x2cc8, 0x6951, 0x6263, 0x27fa,
+ 0x2d97, 0x680e, 0x633c, 0x26a5, 0x7558, 0x30c1, 0x3bf3, 0x7e6a, 0x5990, 0x1c09, 0x173b, 0x52a2, 0x015f, 0x44c6, 0x4ff4, 0x0a6d,
+ 0x5b2e, 0x1eb7, 0x1585, 0x501c, 0x03e1, 0x4678, 0x4d4a, 0x08d3, 0x2f29, 0x6ab0, 0x6182, 0x241b, 0x77e6, 0x327f, 0x394d, 0x7cd4,
+ 0x76b9, 0x3320, 0x3812, 0x7d8b, 0x2e76, 0x6bef, 0x60dd, 0x2544, 0x02be, 0x4727, 0x4c15, 0x098c, 0x5a71, 0x1fe8, 0x14da, 0x5143,
+ 0x73c5, 0x365c, 0x3d6e, 0x78f7, 0x2b0a, 0x6e93, 0x65a1, 0x2038, 0x07c2, 0x425b, 0x4969, 0x0cf0, 0x5f0d, 0x1a94, 0x11a6, 0x543f,
+ 0x5e52, 0x1bcb, 0x10f9, 0x5560, 0x069d, 0x4304, 0x4836, 0x0daf, 0x2a55, 0x6fcc, 0x64fe, 0x2167, 0x729a, 0x3703, 0x3c31, 0x79a8,
+ 0x28eb, 0x6d72, 0x6640, 0x23d9, 0x7024, 0x35bd, 0x3e8f, 0x7b16, 0x5cec, 0x1975, 0x1247, 0x57de, 0x0423, 0x41ba, 0x4a88, 0x0f11,
+ 0x057c, 0x40e5, 0x4bd7, 0x0e4e, 0x5db3, 0x182a, 0x1318, 0x5681, 0x717b, 0x34e2, 0x3fd0, 0x7a49, 0x29b4, 0x6c2d, 0x671f, 0x2286,
+ 0x2213, 0x678a, 0x6cb8, 0x2921, 0x7adc, 0x3f45, 0x3477, 0x71ee, 0x5614, 0x138d, 0x18bf, 0x5d26, 0x0edb, 0x4b42, 0x4070, 0x05e9,
+ 0x0f84, 0x4a1d, 0x412f, 0x04b6, 0x574b, 0x12d2, 0x19e0, 0x5c79, 0x7b83, 0x3e1a, 0x3528, 0x70b1, 0x234c, 0x66d5, 0x6de7, 0x287e,
+ 0x793d, 0x3ca4, 0x3796, 0x720f, 0x21f2, 0x646b, 0x6f59, 0x2ac0, 0x0d3a, 0x48a3, 0x4391, 0x0608, 0x55f5, 0x106c, 0x1b5e, 0x5ec7,
+ 0x54aa, 0x1133, 0x1a01, 0x5f98, 0x0c65, 0x49fc, 0x42ce, 0x0757, 0x20ad, 0x6534, 0x6e06, 0x2b9f, 0x7862, 0x3dfb, 0x36c9, 0x7350,
+ 0x51d6, 0x144f, 0x1f7d, 0x5ae4, 0x0919, 0x4c80, 0x47b2, 0x022b, 0x25d1, 0x6048, 0x6b7a, 0x2ee3, 0x7d1e, 0x3887, 0x33b5, 0x762c,
+ 0x7c41, 0x39d8, 0x32ea, 0x7773, 0x248e, 0x6117, 0x6a25, 0x2fbc, 0x0846, 0x4ddf, 0x46ed, 0x0374, 0x5089, 0x1510, 0x1e22, 0x5bbb,
+ 0x0af8, 0x4f61, 0x4453, 0x01ca, 0x5237, 0x17ae, 0x1c9c, 0x5905, 0x7eff, 0x3b66, 0x3054, 0x75cd, 0x2630, 0x63a9, 0x689b, 0x2d02,
+ 0x276f, 0x62f6, 0x69c4, 0x2c5d, 0x7fa0, 0x3a39, 0x310b, 0x7492, 0x5368, 0x16f1, 0x1dc3, 0x585a, 0x0ba7, 0x4e3e, 0x450c, 0x0095
+};
+
+/**
+ * Update the crc value with new data.
+ *
+ * \param crc The current crc value.
+ * \param data Pointer to a buffer of \a data_len bytes.
+ * \param data_len Number of bytes in the \a data buffer.
+ * \return The updated crc value.
+ *****************************************************************************/
+crc_t crc_update_bytewise(crc_t crc, const unsigned char *data, size_t data_len)
+{
+ unsigned int tbl_idx;
+
+ while (data_len--) {
+ tbl_idx = ((crc >> 7) ^ *data) & 0xff;
+ crc = (crc_table[tbl_idx] ^ (crc << 8)) & 0x7fff;
+
+ data++;
+ }
+ return crc & 0x7fff;
+}
+
+/**
+ * Update the crc value with new data.
+ *
+ * \param crc The current crc value.
+ * \param data Data value
+ * \param bits The number of most significant bits in data used for CRC calculation
+ * \return The updated crc value.
+ *****************************************************************************/
+crc_t crc_update_bitwise(crc_t crc, uint8_t data, size_t bits)
+{
+ uint8_t i;
+ bool bit;
+
+ for (i = 0x80; bits--; i >>= 1) {
+ bit = crc & 0x4000;
+ if (data & i) {
+ bit = !bit;
+ }
+ crc <<= 1;
+ if (bit) {
+ crc ^= 0x4599;
+ }
+ }
+ return crc & 0x7fff;
+}
+
+crc_t calc_bitmap_crc(uint8_t *bitmap, unsigned start, unsigned end)
+{
+ crc_t crc = 0;
+
+ if (start%8) {
+ crc = crc_update_bitwise(crc, bitmap[start/8] << (start%8), 8 - start%8);
+ start += 8 - start%8;
+ }
+ crc = crc_update_bytewise(crc, &bitmap[start/8], (end - start) / 8);
+ crc = crc_update_bitwise(crc, bitmap[end/8], end%8);
+ return crc;
+}
+
+void print_bitmap(const char *prefix, uint8_t *bitmap, unsigned start, unsigned end)
+{
+ int i;
+ printf("%s", prefix);
+ for (i = start; i < end; i++)
+ printf("%c", (bitmap[i/8] << (i % 8)) & 0x80 ? '1' : '0');
+ if (*prefix)
+ printf("\n");
+}
+
+unsigned calc_stuff_bits(struct can_frame *frame) {
+ uint8_t bitmap[16];
+ unsigned start = 0, end;
+
+ char received[64];
+ sprint_canframe(received, frame, true);
+ printf("Frame: %s\n", received);
+
+ memset(bitmap, 0, sizeof(bitmap));
+
+ if (frame->can_id & CAN_EFF_FLAG) {
+ // bit 7 0 7 0 7 0 7 0
+ // bitmap[0-3] |.sBBBBBB BBBBBSIE EEEEEEEE EEEEEEEE| s = SOF, B = Base ID (11 bits), S = SRR, I = IDE, E = Extended ID (18 bits)
+ // bitmap[4-7] |ER10DLC4 00000000 11111111 22222222| R = RTR, 0 = r0, 1 = r1, DLC4 = DLC, Data bytes
+ // bitmap[8-11] |33333333 44444444 55555555 66666666| Data bytes
+ // bitmap[12-15] |77777777 ........ ........ ........| Data bytes
+ bitmap[0] = (frame->can_id & CAN_EFF_MASK) >> 23;
+ bitmap[1] = ((frame->can_id >> 18) & 0x3f) << 3 |
+ 3 << 1 | /* SRR, IDE */
+ ((frame->can_id >> 17) & 0x01);
+ bitmap[2] = (frame->can_id >> 9) & 0xff;
+ bitmap[3] = (frame->can_id >> 1) & 0xff;
+ bitmap[4] = (frame->can_id & 0x1) << 7 |
+ (!!(frame->can_id & CAN_RTR_FLAG)) << 6 |
+ 0 << 4 | /* r1, r0 */
+ frame->can_dlc & 0xf;
+ memcpy(&bitmap[5], &frame->data, frame->can_dlc);
+ start = 1;
+ end = 40 + 8*frame->can_dlc;
+ } else {
+ // bit 7 0 7 0 7 0 7 0
+ // bitmap[0-3] |.....sII IIIIIIII IRE0DLC4 00000000| s = SOF, I = ID (11 bits), R = RTR, E = IDE, DLC4 = DLC
+ // bitmap[4-7] |11111111 22222222 33333333 44444444| Data bytes
+ // bitmap[8-11] |55555555 66666666 77777777 ........| Data bytes
+ bitmap[0] = (frame->can_id & CAN_SFF_MASK) >> 9;
+ bitmap[1] = (frame->can_id >> 1) & 0xff;
+ bitmap[2] = (frame->can_id << 7) & 0xff |
+ (!!(frame->can_id & CAN_RTR_FLAG)) << 6 |
+ 0 << 4 | /* IDE, r0 */
+ frame->can_dlc & 0xf;
+ memcpy(&bitmap[3], &frame->data, frame->can_dlc);
+ start = 5;
+ end = 24 + 8*frame->can_dlc;
+ }
+
+ crc_t crc = calc_bitmap_crc(bitmap, start, end);
+ uint16_t crc_be = htons(crc << 1);
+ assert(end%8 == 0);
+ memcpy(bitmap + end/8, &crc_be, 2);
+ print_bitmap("Frame: ", bitmap, start, end);
+ end += 15;
+ print_bitmap("FrameCRC: ", bitmap, start, end);
+
+ uint8_t mask, ones = 0, basemask = 0xf8;
+ unsigned stuffed = 0;
+ while (start < end) {
+ start++; /* FIXME: This loop is currently broken!!! */
+ mask = basemask >> (start%32);
+ while (1) {
+ ones = ones ? mask : 0;
+ uint32_t chunk = (bitmap[start/32] & mask) ^ ones;
+ //printf("start=%d bitmap=0x%08x mask=0x%08x ones=0x%08x chunk=0x%08x\n", start, bitmap[start >> 5], mask, ones, chunk);
+ if (chunk) {
+ unsigned change = __builtin_clz(chunk);
+ start = start & ~0x1f | change;
+ basemask = 0xf8000000;
+ } else {
+ unsigned oldstart = start;
+ start += __builtin_popcount(mask);
+ mask = (oldstart & 0x1f) ? basemask << (-oldstart & 0x1f) : 0;
+ //printf("oldstart=%d shl=%d mask=0x%08x\n", oldstart, -oldstart & 0x1f, mask);
+ if (mask && start < end)
+ continue;
+ if (start <= end && !mask) {
+ stuffed++;
+ basemask = 0xf0000000;
+ //printf("stuffed %d\n", !ones);
+ }
+ }
+ break;
+ }
+ ones = !ones;
+ }
+ //printf ("STUFFED %d BITS\n", stuffed);
+ return stuffed;
+}
+
+unsigned calc_frame_length(struct can_frame *frame)
+{
+ return calc_stuff_bits(frame) +
+ 1 + /* SOF */
+ 11 + /* ID A */
+ ((frame->can_id & CAN_EFF_FLAG) ?
+ 1 + /* SRR */
+ 1 + /* IDE */
+ 18 + /* ID B */
+ 1 + /* RTR */
+ 2 /* r1, r0 */
+ :
+ 1 + /* rtr */
+ 2) + /* ide, r0 */
+ 4 + /* dlc */
+ 8*frame->can_dlc +
+ 15 + /* CRC */
+ 3 + /* CRC del, ACK, ACK del */
+ 7; /* EOF */
+}
projects / can-benchmark.git / blobdiff