mirror of
https://github.com/davidgiven/fluxengine.git
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93 lines
2.4 KiB
C++
93 lines
2.4 KiB
C++
#include "globals.h"
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#include "fluxmap.h"
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#include "decoders/fluxmapreader.h"
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#include "protocol.h"
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#include "record.h"
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#include "decoders/decoders.h"
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#include "sector.h"
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#include "c64.h"
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#include "crc.h"
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#include "bytes.h"
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#include "fmt/format.h"
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#include <string.h>
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#include <algorithm>
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const FluxPattern SECTOR_RECORD_PATTERN(20, C64_SECTOR_RECORD);
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const FluxPattern DATA_RECORD_PATTERN(20, C64_DATA_RECORD);
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const FluxMatchers ANY_RECORD_PATTERN({ &SECTOR_RECORD_PATTERN, &DATA_RECORD_PATTERN });
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static int decode_data_gcr(uint8_t gcr)
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{
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switch (gcr)
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{
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#define GCR_ENTRY(gcr, data) \
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case gcr: return data;
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#include "data_gcr.h"
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#undef GCR_ENTRY
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}
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return -1;
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};
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static Bytes decode(const std::vector<bool>& bits)
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{
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Bytes output;
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ByteWriter bw(output);
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BitWriter bitw(bw);
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auto ii = bits.begin();
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while (ii != bits.end())
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{
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uint8_t inputfifo = 0;
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for (size_t i=0; i<5; i++)
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{
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if (ii == bits.end())
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break;
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inputfifo = (inputfifo<<1) | *ii++;
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}
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bitw.push(decode_data_gcr(inputfifo), 4);
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}
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bitw.flush();
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return output;
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}
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AbstractDecoder::RecordType Commodore64Decoder::advanceToNextRecord()
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{
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const FluxMatcher* matcher = nullptr;
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_sector->clock = _fmr->seekToPattern(ANY_RECORD_PATTERN, matcher);
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if (matcher == &SECTOR_RECORD_PATTERN)
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return RecordType::SECTOR_RECORD;
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if (matcher == &DATA_RECORD_PATTERN)
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return RecordType::DATA_RECORD;
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return RecordType::UNKNOWN_RECORD;
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}
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void Commodore64Decoder::decodeSectorRecord()
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{
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readRawBits(20);
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const auto& bits = readRawBits(5*10);
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const auto& bytes = decode(bits).slice(0, 5);
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uint8_t checksum = bytes[0];
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_sector->logicalSector = bytes[1];
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_sector->logicalSide = 0;
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_sector->logicalTrack = bytes[2] - 1;
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if (checksum == xorBytes(bytes.slice(1, 4)))
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_sector->status = Sector::DATA_MISSING; /* unintuitive but correct */
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}
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void Commodore64Decoder::decodeDataRecord()
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{
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readRawBits(20);
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const auto& bits = readRawBits(259*10);
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const auto& bytes = decode(bits).slice(0, 259);
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_sector->data = bytes.slice(0, C64_SECTOR_LENGTH);
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uint8_t gotChecksum = xorBytes(_sector->data);
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uint8_t wantChecksum = bytes[256];
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_sector->status = (wantChecksum == gotChecksum) ? Sector::OK : Sector::BAD_CHECKSUM;
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}
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