opendbc/can/packer.cc

108 lines
3.3 KiB
C++

#include <cassert>
#include <utility>
#include <algorithm>
#include <map>
#include <cmath>
#include "common.h"
void set_value(std::vector<uint8_t> &msg, const Signal &sig, int64_t ival) {
int i = sig.lsb / 8;
int bits = sig.size;
if (sig.size < 64) {
ival &= ((1ULL << sig.size) - 1);
}
while (i >= 0 && i < msg.size() && bits > 0) {
int shift = (int)(sig.lsb / 8) == i ? sig.lsb % 8 : 0;
int size = std::min(bits, 8 - shift);
msg[i] &= ~(((1ULL << size) - 1) << shift);
msg[i] |= (ival & ((1ULL << size) - 1)) << shift;
bits -= size;
ival >>= size;
i = sig.is_little_endian ? i+1 : i-1;
}
}
CANPacker::CANPacker(const std::string& dbc_name) {
dbc = dbc_lookup(dbc_name);
assert(dbc);
for (int i = 0; i < dbc->num_msgs; i++) {
const Msg* msg = &dbc->msgs[i];
message_lookup[msg->address] = *msg;
for (int j = 0; j < msg->num_sigs; j++) {
const Signal* sig = &msg->sigs[j];
signal_lookup[std::make_pair(msg->address, std::string(sig->name))] = *sig;
}
}
init_crc_lookup_tables();
}
std::vector<uint8_t> CANPacker::pack(uint32_t address, const std::vector<SignalPackValue> &signals, int counter) {
std::vector<uint8_t> ret(message_lookup[address].size, 0);
// set all values for all given signal/value pairs
for (const auto& sigval : signals) {
auto sig_it = signal_lookup.find(std::make_pair(address, sigval.name));
if (sig_it == signal_lookup.end()) {
// TODO: do something more here. invalid flag like CANParser?
WARN("undefined signal %s - %d\n", sigval.name.c_str(), address);
continue;
}
const auto &sig = sig_it->second;
int64_t ival = (int64_t)(round((sigval.value - sig.offset) / sig.factor));
if (ival < 0) {
ival = (1ULL << sig.size) + ival;
}
set_value(ret, sig, ival);
}
// set message counter
if (counter >= 0){
auto sig_it = signal_lookup.find(std::make_pair(address, "COUNTER"));
if (sig_it == signal_lookup.end()) {
WARN("COUNTER not defined\n");
return ret;
}
const auto& sig = sig_it->second;
if ((sig.type != SignalType::HONDA_COUNTER) && (sig.type != SignalType::VOLKSWAGEN_COUNTER)) {
//WARN("COUNTER signal type not valid\n");
}
set_value(ret, sig, counter);
}
// set message checksum
auto sig_it_checksum = signal_lookup.find(std::make_pair(address, "CHECKSUM"));
if (sig_it_checksum != signal_lookup.end()) {
const auto &sig = sig_it_checksum->second;
if (sig.type == SignalType::HONDA_CHECKSUM) {
unsigned int chksm = honda_checksum(address, ret);
set_value(ret, sig, chksm);
} else if (sig.type == SignalType::TOYOTA_CHECKSUM) {
unsigned int chksm = toyota_checksum(address, ret);
set_value(ret, sig, chksm);
} else if (sig.type == SignalType::VOLKSWAGEN_CHECKSUM) {
unsigned int chksm = volkswagen_crc(address, ret);
set_value(ret, sig, chksm);
} else if (sig.type == SignalType::SUBARU_CHECKSUM) {
unsigned int chksm = subaru_checksum(address, ret);
set_value(ret, sig, chksm);
} else if (sig.type == SignalType::CHRYSLER_CHECKSUM) {
unsigned int chksm = chrysler_checksum(address, ret);
set_value(ret, sig, chksm);
} else {
//WARN("CHECKSUM signal type not valid\n");
}
}
return ret;
}