Calculate stuff bits also for CRC; Fix '=' instead of '=='

[Commit message edited by Michal Sojka]

diff --git a/latester/latester.c b/latester/latester.c
index 140811f86cb539a57d4d82774069b49b02523ad0..a5a7c474dbd837073a932e8bc9ac4fbf39d3bb1f 100644 (file)
--- a/latester/latester.c
+++ b/latester/latester.c
@@ -197,14 +197,40 @@ crc_t crc_update(crc_t crc, uint32_t data, size_t bit_len)
     return crc;
 }
 
+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[3], end > 96 ? end - 96 : 0);
+    return (uint32_t)htons(crc) << 17;
+}
+
+void write_crc_to_bitmap(uint32_t crc, uint32_t *bitmap, struct can_frame *frame)
+{
+    unsigned index = frame->can_id & CAN_EFF_FLAG ? 2 : 1;
+    if (frame->can_dlc < 4)
+        bitmap[index] |= crc >> (frame->can_dlc*8);
+    if (frame->can_dlc == 3)
+        bitmap[index + 1] |= crc << 8;
+    if (frame->can_dlc >= 4 && frame->can_dlc < 8)
+    {
+        bitmap[index + 1] |= crc >> (frame->can_dlc*8);
+        if (frame->can_dlc == 7)
+            bitmap[index + 2] = crc << 8;
+    }
+    else if (frame->can_dlc == 8)
+        bitmap[index + 2] = crc;
+}
+
 unsigned calc_stuff_bits(struct can_frame *frame) {
        uint32_t bitmap[4];
        unsigned start = 0, end;
        uint32_t mask, ones = 0, basemask = 0xf8000000;
        unsigned stuffed = 0;
        memset(bitmap, 0, sizeof(bitmap));
-       crc_t crc = 0;
-       uint32_t crcx;
+       uint32_t crc;
 
 /*     char received[64]; */
 /*     sprint_canframe(received, frame, true); */
@@ -224,17 +250,6 @@ unsigned calc_stuff_bits(struct can_frame *frame) {
                bitmap[3] = htonl(((uint32_t*)frame->data)[1]);
                start = 27;
                end = 64 + 8*frame->can_dlc;
-               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[3], end > 96 ? end - 96 : 0);
-               crcx = (uint32_t)htons(crc) << 17;
-               if (frame->can_dlc < 4)
-                       bitmap[2] |= crcx >> (frame->can_dlc*8);
-               if (frame->can_dlc = 3)
-                       bitmap[3] |= crcx << 8;
-               if (frame->can_dlc >= 4)
-                       bitmap[3] |= crcx >> (frame->can_dlc*8);
        } else {
                bitmap[0] =
                        (frame->can_id << 7) |
@@ -246,7 +261,10 @@ unsigned calc_stuff_bits(struct can_frame *frame) {
                start = 13;
                end = 32 + 8*frame->can_dlc;
        }
-       /* TODO: Calc stuff bits in CRC */
+        crc = calc_bitmap_crc(bitmap, start, end);
+        write_crc_to_bitmap(crc, bitmap, frame);
+        end += 15;
+
        while (start < end) {
                mask = basemask >> (start & 0x1f);
                while (1) {