Files
fluxengine/arch/victor9k/decoder.cc
2025-03-17 22:33:54 +01:00

120 lines
3.1 KiB
C++

#include "lib/core/globals.h"
#include "lib/data/fluxmap.h"
#include "lib/data/fluxmapreader.h"
#include "lib/data/fluxpattern.h"
#include "protocol.h"
#include "lib/decoders/decoders.h"
#include "lib/data/sector.h"
#include "arch/victor9k/victor9k.h"
#include "lib/core/crc.h"
#include "lib/core/bytes.h"
#include "fmt/format.h"
#include <string.h>
#include <algorithm>
const FluxPattern SECTOR_RECORD_PATTERN(32, VICTOR9K_SECTOR_RECORD);
const FluxPattern DATA_RECORD_PATTERN(32, VICTOR9K_DATA_RECORD);
const FluxMatchers ANY_RECORD_PATTERN(
{&SECTOR_RECORD_PATTERN, &DATA_RECORD_PATTERN});
static int decode_data_gcr(uint8_t gcr)
{
switch (gcr)
{
#define GCR_ENTRY(gcr, data) \
case gcr: \
return data;
#include "data_gcr.h"
#undef GCR_ENTRY
}
return -1;
}
static Bytes decode(const std::vector<bool>& bits)
{
Bytes output;
ByteWriter bw(output);
BitWriter bitw(bw);
auto ii = bits.begin();
while (ii != bits.end())
{
uint8_t inputfifo = 0;
for (size_t i = 0; i < 5; i++)
{
if (ii == bits.end())
break;
inputfifo = (inputfifo << 1) | *ii++;
}
uint8_t decoded = decode_data_gcr(inputfifo);
bitw.push(decoded, 4);
}
bitw.flush();
return output;
}
class Victor9kDecoder : public Decoder
{
public:
Victor9kDecoder(const DecoderProto& config): Decoder(config) {}
nanoseconds_t advanceToNextRecord() override
{
return seekToPattern(ANY_RECORD_PATTERN);
}
void decodeSectorRecord() override
{
/* Check the ID. */
if (readRaw32() != VICTOR9K_SECTOR_RECORD)
return;
/* Read header. */
auto bytes = decode(readRawBits(3 * 10)).slice(0, 3);
uint8_t rawTrack = bytes[0];
_sector->logicalSector = bytes[1];
uint8_t gotChecksum = bytes[2];
_sector->logicalTrack = rawTrack & 0x7f;
_sector->logicalSide = rawTrack >> 7;
uint8_t wantChecksum = bytes[0] + bytes[1];
if ((_sector->logicalSector > 20) || (_sector->logicalTrack > 85) ||
(_sector->logicalSide > 1))
return;
if (wantChecksum == gotChecksum)
_sector->status =
Sector::DATA_MISSING; /* unintuitive but correct */
}
void decodeDataRecord() override
{
/* Check the ID. */
if (readRaw32() != VICTOR9K_DATA_RECORD)
return;
/* Read data. */
auto bytes = decode(readRawBits((VICTOR9K_SECTOR_LENGTH + 4) * 10))
.slice(0, VICTOR9K_SECTOR_LENGTH + 4);
ByteReader br(bytes);
_sector->data = br.read(VICTOR9K_SECTOR_LENGTH);
uint16_t gotChecksum = sumBytes(_sector->data);
uint16_t wantChecksum = br.read_le16();
_sector->status =
(gotChecksum == wantChecksum) ? Sector::OK : Sector::BAD_CHECKSUM;
}
};
std::unique_ptr<Decoder> createVictor9kDecoder(const DecoderProto& config)
{
return std::unique_ptr<Decoder>(new Victor9kDecoder(config));
}