betaflight-configurator/js/workers/hex_parser.js

108 lines
4.0 KiB
JavaScript

// input = string
// result = if hex file is valid, result is an object
// if hex file wasn't valid (crc check failed on any of the lines), result will be false
function read_hex_file(data) {
data = data.split("\n");
// check if there is an empty line in the end of hex file, if there is, remove it
if (data[data.length - 1] == "") {
data.pop();
}
var hexfile_valid = true; // if any of the crc checks failed, this variable flips to false
var result = {
data: [],
end_of_file: false,
bytes_total: 0,
start_linear_address: 0
};
var extended_linear_address = 0;
var next_address = 0;
for (var i = 0; i < data.length && hexfile_valid; i++) {
// each byte is represnted by two chars
var byte_count = parseInt(data[i].substr(1, 2), 16);
var address = parseInt(data[i].substr(3, 4), 16);
var record_type = parseInt(data[i].substr(7, 2), 16);
var content = data[i].substr(9, byte_count * 2); // still in string format
var checksum = parseInt(data[i].substr(9 + byte_count * 2, 2), 16); // (this is a 2's complement value)
switch (record_type) {
case 0x00: // data record
if (address != next_address || next_address == 0) {
result.data.push({'address': extended_linear_address + address, 'bytes': 0, 'data': []});
}
// store address for next comparison
next_address = address + byte_count;
// process data
var crc = byte_count + parseInt(data[i].substr(3, 2), 16) + parseInt(data[i].substr(5, 2), 16) + record_type;
for (var needle = 0; needle < byte_count * 2; needle += 2) { // * 2 because of 2 hex chars per 1 byte
var num = parseInt(content.substr(needle, 2), 16); // get one byte in hex and convert it to decimal
var data_block = result.data.length - 1;
result.data[data_block].data.push(num);
result.data[data_block].bytes++;
crc += num;
result.bytes_total++;
}
// change crc to 2's complement
crc = (~crc + 1) & 0xFF;
// verify
if (crc != checksum) {
hexfile_valid = false;
}
break;
case 0x01: // end of file record
result.end_of_file = true;
break;
case 0x02: // extended segment address record
// not implemented
if (parseInt(content, 16) != 0) { // ignore if segment is 0
console.log('extended segment address record found - NOT IMPLEMENTED !!!');
}
break;
case 0x03: // start segment address record
// not implemented
if (parseInt(content, 16) != 0) { // ignore if segment is 0
console.log('start segment address record found - NOT IMPLEMENTED !!!');
}
break;
case 0x04: // extended linear address record
extended_linear_address = (parseInt(content.substr(0, 2), 16) << 24) | parseInt(content.substr(2, 2), 16) << 16;
break;
case 0x05: // start linear address record
result.start_linear_address = parseInt(content, 16)
break;
}
}
if (result.end_of_file && hexfile_valid) {
postMessage(result);
} else {
postMessage(false);
}
}
function microtime() {
var now = new Date().getTime() / 1000;
return now;
}
onmessage = function(event) {
var time_parsing_start = microtime(); // track time
read_hex_file(event.data);
console.log('HEX_PARSER - File parsed in: ' + (microtime() - time_parsing_start).toFixed(4) + ' seconds');
// terminate worker
close();
};