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This change properly parses Big Endian signals #11

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This change properly parses Big Endian signals #11

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2ac9245
extract big endian values
kazoo11 Apr 19, 2023
219fe64
Package executable
kazoo11 Apr 19, 2023
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Binary file modified bin/cangaroo.zip
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2 changes: 1 addition & 1 deletion src/core/CanDbSignal.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -209,7 +209,7 @@ void CanDbSignal::setMuxValue(const uint32_t &muxValue)

bool CanDbSignal::isPresentInMessage(const CanMessage &msg)
{
if ((_startBit + _length)>(8*msg.getLength())) {
if ((_startBit + _length)>(8*msg.getLength()) && !_isBigEndian) {
return false;
}

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39 changes: 28 additions & 11 deletions src/core/CanMessage.cpp
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Expand Up @@ -184,6 +184,34 @@ void CanMessage::setByte(const uint8_t index, const uint8_t value) {

uint64_t CanMessage::extractRawSignal(uint8_t start_bit, const uint8_t length, const bool isBigEndian) const
{
if(isBigEndian)
{
int firstByte = start_bit / 8;
uint64_t data = _u8[firstByte];
data &= (0xFF >> (7 - start_bit%8));

int lastByte = firstByte;
int len = length - (start_bit%8 + 1);

if(len > 0)
lastByte += (len/8)+1;

for(int i = firstByte; i < lastByte; i++)
{
data <<= 8;
data |= _u8[i+1];
}

int shiftAmount = start_bit%8 - length%8 + 1;
if(shiftAmount < 0)
shiftAmount += 8;
else if(shiftAmount == 8)
shiftAmount = 0;
data >>= shiftAmount;

return data;
}

// if ((start_bit+length) > (getLength()*8)) {
// return 0;
// }
Expand All @@ -199,17 +227,6 @@ uint64_t CanMessage::extractRawSignal(uint8_t start_bit, const uint8_t length, c

data &= mask;

// If the length is greater than 8, we need to byteswap to preserve endianness
if (isBigEndian && (length > 8))
{

// Swap bytes
data = __builtin_bswap64(data);

// Shift out unused bits
data >>= 64 - length;
}

return data;
}

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15 changes: 0 additions & 15 deletions src/parser/dbc/DbcParser.cpp
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Expand Up @@ -552,21 +552,6 @@ bool DbcParser::parseSectionBoSg(CanDb &candb, CanDbMessage *msg, DbcTokenList &
if (!expectInt(tokens, &byte_order)) { return false; }
signal->setIsBigEndian(byte_order==0);

// If the signal is big endian, convert the start bit to the Intel-style start bit for further parsing
if(signal->isBigEndian())
{
// This will be the number of 8-bit rows above the message
uint8_t row_position = signal->startBit() >> 3;

// Bit position in current row (0-7)
uint8_t column_position = signal->startBit() & 0b111;

// Calcualte the normalized start bit position (bit index starting at 0)
uint8_t normalized_position = (row_position * 8) + (7 - column_position);

signal->setStartBit(normalized_position);
}

if (expectAndSkipToken(tokens, dbc_tok_plus)) {
signal->setUnsigned(true);
} else {
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