diff options
Diffstat (limited to 'src/lib/formats/dmk_dsk.cpp')
-rw-r--r-- | src/lib/formats/dmk_dsk.cpp | 337 |
1 files changed, 232 insertions, 105 deletions
diff --git a/src/lib/formats/dmk_dsk.cpp b/src/lib/formats/dmk_dsk.cpp index 5ca0a3b8781..d02401b56cf 100644 --- a/src/lib/formats/dmk_dsk.cpp +++ b/src/lib/formats/dmk_dsk.cpp @@ -2,57 +2,91 @@ // copyright-holders:Wilbert Pol /********************************************************************* - formats/dmk_dsk.h + formats/dmk_dsk.cpp DMK disk images TODO: - Add write/format support. -- Add single density support. -- Check support on other drivers besides msx. +- Check support on other drivers besides MSX. *********************************************************************/ -#include <assert.h> - #include "dmk_dsk.h" +#include "coretmpl.h" +#include "ioprocs.h" +#include "multibyte.h" + +#include <tuple> + + +namespace { + +constexpr int HEADER_SIZE = 16; + +uint32_t wide_fm(uint16_t val) +{ + uint32_t res = 0; + for (int i = 15; i >= 0; i--) { + res |= (util::BIT(val, i) << (i * 2 + 1)); + } + return res; +} + +uint32_t data_to_wide_fm(uint8_t val) +{ + uint16_t res = 0xaaaa; // clock + for (int i = 7; i >= 0; i--) { + res |= (util::BIT(val, i) << i * 2); // data + } + return wide_fm(res); +} + +} // anonymous namespace + + dmk_format::dmk_format() { } -const char *dmk_format::name() const +const char *dmk_format::name() const noexcept { return "dmk"; } -const char *dmk_format::description() const +const char *dmk_format::description() const noexcept { return "DMK disk image"; } -const char *dmk_format::extensions() const +const char *dmk_format::extensions() const noexcept { return "dmk"; } -int dmk_format::identify(io_generic *io, uint32_t form_factor) +int dmk_format::identify(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants) const { - const int header_size = 16; - uint8_t header[header_size]; + uint64_t size; + if (io.length(size)) + return 0; - uint64_t size = io_generic_size(io); + std::error_condition err; + size_t actual; - io_generic_read(io, header, 0, header_size); + uint8_t header[HEADER_SIZE]; + std::tie(err, actual) = read_at(io, 0, header, HEADER_SIZE); + if (err || (HEADER_SIZE != actual)) + return 0; - int tracks = header[1]; - int track_size = ( header[3] << 8 ) | header[2]; - int heads = (header[4] & 0x10) ? 1 : 2; + const int tracks_from_header = header[1]; + const int track_size = get_u16le(&header[2]); + const int heads = util::BIT(header[4], 4) ? 1 : 2; // The first header byte must be 00 or FF if (header[0] != 0x00 && header[0] != 0xff) @@ -60,149 +94,249 @@ int dmk_format::identify(io_generic *io, uint32_t form_factor) return 0; } - // Bytes C-F must be zero - if (header[0x0c] != 0 || header[0xd] != 0 || header[0xe] != 0 || header[0xf] != 0) + // Verify reserved/unsupported header bytes + for (int i = 5; i < 0x10; i++) { - return 0; + if (header[i] != 0x00) + return 0; } // Check track size within limits - if (track_size < 0x80 || track_size > 0x3FFF ) - { + if (track_size < 0x80 || track_size > 0x3fff) return 0; - } - if (size == header_size + heads * tracks * track_size) + const int tracks_in_file = (size - HEADER_SIZE) / (heads * track_size); + for (int track = 0; track < tracks_in_file; track++) { - return 70; - } + for (int head = 0; head < heads; head++) + { + // Read track + std::vector<uint8_t> track_data(track_size); + std::tie(err, actual) = read_at(io, HEADER_SIZE + (heads * track + head) * track_size, &track_data[0], track_size); + if (err || track_size != actual) + return 0; - return 0; + // Verify idam entries + for (int idam_index = 0; idam_index < 64; idam_index++) + { + const uint16_t idam_entry = get_u16le(&track_data[2 * idam_index]); + if (idam_entry == 0x0000) + continue; + const uint16_t idam_offset = idam_entry & 0x3fff; + if (idam_offset >= track_size) + return 0; + if (track_data[idam_offset] != 0xfe) + return 0; + } + } + } + if (size == HEADER_SIZE + heads * tracks_from_header * track_size) + return FIFID_HINT|FIFID_SIZE; + else + return FIFID_HINT; } -bool dmk_format::load(io_generic *io, uint32_t form_factor, floppy_image *image) +bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image &image) const { - const int header_size = 16; - uint8_t header[header_size]; + std::error_condition err; + size_t actual; - io_generic_read(io, header, 0, header_size); + uint64_t size; + if (io.length(size)) + return false; - const int tracks = header[1]; - const int track_size = ( header[3] << 8 ) | header[2]; - const int heads = (header[4] & 0x10) ? 1 : 2; - const bool is_sd = (header[4] & 0x40) ? true : false; - //const int raw_track_size = 2 * 8 * ( track_size - 0x80 ); + uint8_t header[HEADER_SIZE]; + std::tie(err, actual) = read_at(io, 0, header, HEADER_SIZE); + if (err || (HEADER_SIZE != actual)) + return false; - if (is_sd) - { - if (heads == 2) - { - image->set_variant(floppy_image::DSSD); - } - else - { - image->set_variant(floppy_image::SSSD); - } - } - else - { - if (heads == 2) - { - image->set_variant(floppy_image::DSDD); - } - else - { - image->set_variant(floppy_image::SSDD); - } - } + const int track_size = get_u16le(&header[2]); + const int heads = util::BIT(header[4], 4) ? 1 : 2; + const bool is_sd = util::BIT(header[4], 6); + const int tracks = (size - HEADER_SIZE) / (heads * track_size); + + const auto variant = is_sd ? (heads == 2 ? floppy_image::DSSD : floppy_image::SSSD) + : (heads == 2 ? floppy_image::DSDD : floppy_image::SSDD); + image.set_variant(variant); + + const int fm_stride = is_sd ? 1 : 2; for (int track = 0; track < tracks; track++) { for (int head = 0; head < heads; head++) { + int fm_loss = 0; std::vector<uint8_t> track_data(track_size); std::vector<uint32_t> raw_track_data; + int mark_location[64 * 2 + 1]; + uint8_t mark_value[64 * 2 + 1]; + bool mark_is_mfm[64 * 2 + 1]; int iam_location = -1; - int idam_location[64]; - int dam_location[64]; // Read track - io_generic_read(io, &track_data[0], header_size + ( heads * track + head ) * track_size, track_size); + std::tie(err, actual) = read_at(io, HEADER_SIZE + (heads * track + head) * track_size, &track_data[0], track_size); + if (err || track_size != actual) + return false; - for (int i = 0; i < 64; i++) + for (int i = 0; i < 64 * 2 + 1; i++) { - idam_location[i] = -1; - dam_location[i] = -1; + mark_location[i] = -1; + mark_value[i] = 0xfe; + mark_is_mfm[i] = !is_sd; // Use default encoding } + int mark_count = 0; - // Find IDAM locations + // Find IDAM/DAM locations uint16_t track_header_offset = 0; - uint16_t track_offset = ( ( track_data[track_header_offset + 1] << 8 ) | track_data[track_header_offset] ) & 0x3fff; + uint16_t track_offset = get_u16le(&track_data[track_header_offset]) & 0x3fff; + bool idam_is_mfm = util::BIT(track_data[track_header_offset + 1], 7); track_header_offset += 2; - while ( track_offset != 0 && track_offset >= 0x83 && track_offset < track_size && track_header_offset < 0x80 ) + while (track_offset != 0 && track_offset >= 0x83 && track_offset < track_size && track_header_offset < 0x80) { // Assume 3 bytes before IDAM pointers are the start of IDAM indicators - idam_location[(track_header_offset/2) - 1] = track_offset - 3; + int mark_offset = idam_is_mfm ? 3 : 0; + mark_location[mark_count] = track_offset - mark_offset; + mark_value[mark_count] = 0xfe; + mark_is_mfm[mark_count] = idam_is_mfm; + mark_count++; + int stride = idam_is_mfm ? 1 : fm_stride; // Scan for DAM location - for (int i = track_offset + 53; i > track_offset + 10; i--) + for (int i = track_offset + 10 * stride; i < track_offset + 53 * stride; i++) { - if ((track_data[i] == 0xfb || track_data[i] == 0xf8) && track_data[i-1] == 0xa1 && track_data[i-2] == 0xa1) + if ((track_data[i] >= 0xf8 && track_data[i] <= 0xfb)) { - dam_location[(track_header_offset/2) - 1] = i - 3; - break; + if (!idam_is_mfm || get_u16le(&track_data[i - 2]) == 0xa1a1) + { + mark_location[mark_count] = i - mark_offset; + mark_value[mark_count] = track_data[i]; + mark_is_mfm[mark_count] = idam_is_mfm; + mark_count++; + + break; + } } } - track_offset = ( ( track_data[track_header_offset + 1] << 8 ) | track_data[track_header_offset] ) & 0x3fff; + idam_is_mfm = util::BIT(track_data[track_header_offset + 1], 7); + track_offset = get_u16le(&track_data[track_header_offset]) & 0x3fff; track_header_offset += 2; - }; + } + + // Prevent encoding from switching after last sector + if (mark_count > 0) + { + mark_is_mfm[mark_count] = mark_is_mfm[mark_count - 1]; + } // Find IAM location - for(int i = idam_location[0] - 1; i >= 3; i--) + for (int i = mark_location[0] - 1; i >= 3; i--) { // It's usually 3 bytes but several dumped tracks seem to contain only 2 bytes - if (track_data[i] == 0xfc && track_data[i-1] == 0xc2 && track_data[i-2] == 0xc2) + if (track_data[i] == 0xfc && (is_sd || get_u16le(&track_data[i - 2]) == 0xc2c2)) { - iam_location = i - 3; + iam_location = i - (is_sd ? 0 : 3); break; } } - int idam_index = 0; - int dam_index = 0; + int curr_mark = 0; + bool enc_mfm = mark_is_mfm[curr_mark]; for (int offset = 0x80; offset < track_size; offset++) { if (offset == iam_location) { - // Write IAM - raw_w(raw_track_data, 16, 0x5224); - raw_w(raw_track_data, 16, 0x5224); - raw_w(raw_track_data, 16, 0x5224); - offset += 3; + if (!is_sd) + { + // Write IAM + raw_w(raw_track_data, 16, 0x5224); + raw_w(raw_track_data, 16, 0x5224); + raw_w(raw_track_data, 16, 0x5224); + offset += 3; + } + else + { + raw_w(raw_track_data, 32, wide_fm(0xf77a)); // FC clocked with D7 + offset += fm_stride; + } } - if (offset == idam_location[idam_index]) + // If close to mark, switch encoding + if (offset + 8 >= mark_location[curr_mark]) + { + bool new_enc = mark_is_mfm[curr_mark]; + if (new_enc != enc_mfm) + { + enc_mfm = new_enc; + } + } + if (offset == mark_location[curr_mark] + || (!enc_mfm && offset - fm_stride + 1 == mark_location[curr_mark]) + ) { - raw_w(raw_track_data, 16, 0x4489); - raw_w(raw_track_data, 16, 0x4489); - raw_w(raw_track_data, 16, 0x4489); - idam_index += 1; - offset += 3; + if (enc_mfm) + { + raw_w(raw_track_data, 16, 0x4489); + raw_w(raw_track_data, 16, 0x4489); + raw_w(raw_track_data, 16, 0x4489); + offset += 3; + if (fm_stride == 1) + { + fm_loss += 3; + } + } + else + { + uint16_t mark; + switch (mark_value[curr_mark]) + { + default: + case 0xfb: mark = 0xf56f; break; + case 0xfa: mark = 0xf56e; break; + case 0xf9: mark = 0xf56b; break; + case 0xf8: mark = 0xf56a; break; + case 0xfe: mark = 0xf57e; break; + } + raw_w(raw_track_data, 32, wide_fm(mark)); + offset += fm_stride; + } + curr_mark++; } - if (offset == dam_location[dam_index]) + if (enc_mfm) { - raw_w(raw_track_data, 16, 0x4489); - raw_w(raw_track_data, 16, 0x4489); - raw_w(raw_track_data, 16, 0x4489); - dam_index += 1; - offset += 3; + if (fm_stride == 1) + { + fm_loss++; + } + mfm_w(raw_track_data, 8, track_data[offset]); } + else + raw_w(raw_track_data, 32, data_to_wide_fm(track_data[offset])); + + + if (!enc_mfm) + offset += fm_stride - 1; + } - mfm_w(raw_track_data, 8, track_data[offset]); + if (fm_loss != 0) + { + if (enc_mfm) + { + for (int jj = 0; jj < fm_loss; jj++) + { + mfm_w(raw_track_data, 8, 0x4e); + } + } + else + { + for (int jj = 0; jj < fm_loss/2; jj++) + { + raw_w(raw_track_data, 32, data_to_wide_fm(0xff)); + } + } } generate_track_from_levels(track, head, raw_track_data, 0, image); @@ -212,17 +346,10 @@ bool dmk_format::load(io_generic *io, uint32_t form_factor, floppy_image *image) return true; } - -bool dmk_format::save(io_generic *io, floppy_image *image) -{ - return false; -} - - -bool dmk_format::supports_save() const +bool dmk_format::supports_save() const noexcept { return false; } -const floppy_format_type FLOPPY_DMK_FORMAT = &floppy_image_format_creator<dmk_format>; +const dmk_format FLOPPY_DMK_FORMAT; |