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/* -*- c++ -*- */
/*
* Copyright 2010 Ettus Research LLC
*
*/
#include "ihex.h"
#include <ctype.h> //man that pulls in a lot of shit
//this is not safe and you should run isxdigit beforehand
uint8_t asc2nibble(char input) {
if(input > 'Z') return input - 'W';
else if(input > '9') return input - '7';
else return input - '0';
}
int ihex_parse(char input[], ihex_record_t *record) {
//given a NULL-TERMINATED input string (use gets()) in I16HEX format, write the binary record in record. return 0 on success.
uint8_t inputlen;
uint8_t t, i, checksum_calc=0, checksum_read;
//first check for ":" leading character
if(input[0] != ':') return -1;
//then check the string for only valid ASCII ['0'-'F']
inputlen=1;
while(input[inputlen]) {
if( !isxdigit(input[inputlen++]) ) return -2;
}
//then read the length.
record->length = (asc2nibble(input[1]) << 4) + asc2nibble(input[2]);
if(input[(record->length<<1) + 11] != 0) return -3; //if we're missing a null terminator in the right place
//then read the address.
record->addr = (asc2nibble(input[3]) << 12) + (asc2nibble(input[4]) << 8) + (asc2nibble(input[5]) << 4) + asc2nibble(input[6]);
//then read the record type.
record->type = (asc2nibble(input[7]) << 4) + asc2nibble(input[8]);
// if(record->type > 4) return -4;
//then read the data, which goes from input[9] to input[9+length*2].
for(i=0; i < record->length; i++) {
t = 9 + (i<<1);
record->data[i] = (asc2nibble(input[t]) << 4) + (asc2nibble(input[t + 1]));
checksum_calc += record->data[i]; //might as well keep a running checksum as we read
}
checksum_calc += record->length + record->type + (record->addr >> 8) + (record->addr & 0xFF); //get the rest of the data into that checksum
checksum_calc = ~checksum_calc + 1; //checksum is 2's complement
//now read the checksum of the record
checksum_read = (asc2nibble(input[9 + (record->length<<1)]) << 4) + asc2nibble(input[10 + (record->length<<1)]);
if(checksum_calc != checksum_read) return -5; //compare 'em
return 0;
}
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