Files
fluxengine/arch/micropolis/encoder.cc
2022-09-16 00:20:54 +02:00

113 lines
3.5 KiB
C++

#include "globals.h"
#include "micropolis.h"
#include "sector.h"
#include "decoders/decoders.h"
#include "encoders/encoders.h"
#include "image.h"
#include "lib/encoders/encoders.pb.h"
static void write_sector(std::vector<bool>& bits,
unsigned& cursor,
const std::shared_ptr<const Sector>& sector)
{
if ((sector->data.size() != 256) &&
(sector->data.size() != MICROPOLIS_ENCODED_SECTOR_SIZE))
Error() << "unsupported sector size --- you must pick 256 or 275";
int fullSectorSize = 40 + MICROPOLIS_ENCODED_SECTOR_SIZE + 40 + 35;
auto fullSector = std::make_shared<std::vector<uint8_t>>();
fullSector->reserve(fullSectorSize);
/* sector preamble */
for (int i = 0; i < 40; i++)
fullSector->push_back(0);
Bytes sectorData;
if (sector->data.size() == MICROPOLIS_ENCODED_SECTOR_SIZE)
{
if (sector->data[0] != 0xFF)
Error() << "275 byte sector doesn't start with sync byte 0xFF. "
"Corrupted sector";
uint8_t wantChecksum = sector->data[1 + 2 + 266];
uint8_t gotChecksum =
micropolisChecksum(sector->data.slice(1, 2 + 266));
if (wantChecksum != gotChecksum)
std::cerr << "Warning: checksum incorrect. Sector: "
<< sector->logicalSector << std::endl;
sectorData = sector->data;
}
else
{
ByteWriter writer(sectorData);
writer.write_8(0xff); /* Sync */
writer.write_8(sector->logicalTrack);
writer.write_8(sector->logicalSector);
for (int i = 0; i < 10; i++)
writer.write_8(0); /* Padding */
writer += sector->data;
writer.write_8(micropolisChecksum(sectorData.slice(1)));
for (int i = 0; i < 5; i++)
writer.write_8(0); /* 4 byte ECC and ECC not present flag */
}
for (uint8_t b : sectorData)
fullSector->push_back(b);
/* sector postamble */
for (int i = 0; i < 40; i++)
fullSector->push_back(0);
/* filler */
for (int i = 0; i < 35; i++)
fullSector->push_back(0);
if (fullSector->size() != fullSectorSize)
Error() << "sector mismatched length";
bool lastBit = false;
encodeMfm(bits, cursor, fullSector, lastBit);
/* filler */
for (int i = 0; i < 5; i++)
{
bits[cursor++] = 1;
bits[cursor++] = 0;
}
}
class MicropolisEncoder : public Encoder
{
public:
MicropolisEncoder(const EncoderProto& config):
Encoder(config),
_config(config.micropolis())
{
}
std::unique_ptr<Fluxmap> encode(std::shared_ptr<const TrackInfo>& trackInfo,
const std::vector<std::shared_ptr<const Sector>>& sectors,
const Image& image) override
{
int bitsPerRevolution =
(_config.rotational_period_ms() * 1e3) / _config.clock_period_us();
std::vector<bool> bits(bitsPerRevolution);
unsigned cursor = 0;
for (const auto& sectorData : sectors)
write_sector(bits, cursor, sectorData);
if (cursor != bits.size())
Error() << "track data mismatched length";
std::unique_ptr<Fluxmap> fluxmap(new Fluxmap);
fluxmap->appendBits(bits,
calculatePhysicalClockPeriod(
_config.clock_period_us() * 1e3,
_config.rotational_period_ms() * 1e6));
return fluxmap;
}
private:
const MicropolisEncoderProto& _config;
};
std::unique_ptr<Encoder> createMicropolisEncoder(
const EncoderProto& config)
{
return std::unique_ptr<Encoder>(new MicropolisEncoder(config));
}