Another bug

[can-benchmark.git] / latester / latester.c

diff --git a/latester/latester.c b/latester/latester.c
index a5a7c474dbd837073a932e8bc9ac4fbf39d3bb1f..090676023da5b739e98d9445cafd7d7d1e5cd3c2 100644 (file)
--- a/latester/latester.c
+++ b/latester/latester.c
@@ -1,6 +1,6 @@
 /**************************************************************************/
 /* CAN latency tester                                                     */
-/* Copyright (C) 2010, 2011, 2012 Michal Sojka, DCE FEE CTU Prague        */
+/* Copyright (C) 2010, 2011, 2012, 2013 Michal Sojka, DCE FEE CTU Prague  */
 /* License: GPLv2                                                        */
 /**************************************************************************/
 
@@ -202,9 +202,9 @@ uint32_t calc_bitmap_crc(uint32_t *bitmap, unsigned start, unsigned end)
     crc_t crc = 0;
     crc = crc_update(crc, bitmap[0] << start, 32 - start);
     crc = crc_update(crc, bitmap[1], 32);
-    crc = crc_update(crc, bitmap[2], end - 64 > 32 ? 32 : end - 64);
+    crc = crc_update(crc, bitmap[2], end - 64 > 32 ? 32 : end - 64); /* FIXME: This seems to be broken for end < 64 */
     crc = crc_update(crc, bitmap[3], end > 96 ? end - 96 : 0);
-    return (uint32_t)htons(crc) << 17;
+    return (uint32_t)htons(crc << 17);
 }
 
 void write_crc_to_bitmap(uint32_t crc, uint32_t *bitmap, struct can_frame *frame)
@@ -237,6 +237,11 @@ unsigned calc_stuff_bits(struct can_frame *frame) {
 /*     printf("Frame: %s\n", received); */
        
        if (frame->can_id & CAN_EFF_FLAG) {
+               // bit 31                              0
+               // [0] |...........................sBBBB| s = SOF, B = Base ID (11 bits)
+               // [1] |BBBBBBBSIEEEEEEEEEEEEEEEEEER10DLC4| S = SRR, I = IDE, E = Extended ID (18 bits), DLC4 = DLC
+               // [2] |00000000111111112222222233333333| Data bytes, MSB first
+               // [3] |44444444555555556666666677777777|
                bitmap[0] =
                        ((frame->can_id & CAN_EFF_MASK) >> 25);
                bitmap[1] =
@@ -246,18 +251,20 @@ unsigned calc_stuff_bits(struct can_frame *frame) {
                        (!!(frame->can_id & CAN_RTR_FLAG)) << 6         |
                        0 << 4                                          |
                        frame->can_dlc & 0xf;
-               bitmap[2] = htonl(((uint32_t*)frame->data)[0]);
-               bitmap[3] = htonl(((uint32_t*)frame->data)[1]);
+               memcpy(&bitmap[2], &frame->data, frame->can_dlc);
                start = 27;
                end = 64 + 8*frame->can_dlc;
        } else {
+               // bit 31                              0
+               // [0] |.............sIIIIIIIIIIIRE0DLC4| s = SOF, I = ID (11 bits), R = RTR, E = IDE, DLC4 = DLC
+               // [1] |00000000111111112222222233333333| Data bytes, MSB first
+               // [2] |44444444555555556666666677777777|
                bitmap[0] =
                        (frame->can_id << 7) |
                        (!!(frame->can_id & CAN_RTR_FLAG)) << 6 |
                        0 << 4                                  |
                        frame->can_dlc & 0xf;
-               bitmap[1] = htonl(((uint32_t*)frame->data)[0]);
-               bitmap[2] = htonl(((uint32_t*)frame->data)[1]);
+               memcpy(&bitmap[1], &frame->data, frame->can_dlc);
                start = 13;
                end = 32 + 8*frame->can_dlc;
        }