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Diffstat (limited to 'src/lib/formats/dmk_dsk.cpp')
-rw-r--r--src/lib/formats/dmk_dsk.cpp138
1 files changed, 77 insertions, 61 deletions
diff --git a/src/lib/formats/dmk_dsk.cpp b/src/lib/formats/dmk_dsk.cpp
index 68257ff1f2b..d02401b56cf 100644
--- a/src/lib/formats/dmk_dsk.cpp
+++ b/src/lib/formats/dmk_dsk.cpp
@@ -8,7 +8,7 @@
TODO:
- Add write/format support.
-- Check support on other drivers besides msx.
+- Check support on other drivers besides MSX.
*********************************************************************/
@@ -18,14 +18,18 @@ TODO:
#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));
+ res |= (util::BIT(val, i) << (i * 2 + 1));
}
return res;
}
@@ -34,7 +38,7 @@ 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
+ res |= (util::BIT(val, i) << i * 2); // data
}
return wide_fm(res);
}
@@ -72,14 +76,17 @@ int dmk_format::identify(util::random_read &io, uint32_t form_factor, const std:
if (io.length(size))
return 0;
- const int header_size = 16;
- uint8_t header[header_size];
+ std::error_condition err;
size_t actual;
- io.read_at(0, header, header_size, actual);
- int tracks = header[1];
- int track_size = get_u16le(&header[2]);
- int heads = (header[4] & 0x10) ? 1 : 2;
+ uint8_t header[HEADER_SIZE];
+ std::tie(err, actual) = read_at(io, 0, header, HEADER_SIZE);
+ if (err || (HEADER_SIZE != actual))
+ return 0;
+
+ 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)
@@ -87,66 +94,73 @@ int dmk_format::identify(util::random_read &io, uint32_t form_factor, const std:
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 FIFID_STRUCT|FIFID_SIZE;
- }
+ 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(util::random_read &io, uint32_t form_factor, const std::vector<uint32_t> &variants, floppy_image &image) const
{
+ std::error_condition err;
size_t actual;
- const int header_size = 16;
- uint8_t header[header_size];
- io.read_at(0, header, header_size, actual);
+ uint64_t size;
+ if (io.length(size))
+ return false;
+
+ uint8_t header[HEADER_SIZE];
+ std::tie(err, actual) = read_at(io, 0, header, HEADER_SIZE);
+ if (err || (HEADER_SIZE != actual))
+ return false;
- const int tracks = header[1];
const int track_size = get_u16le(&header[2]);
- const int heads = (header[4] & 0x10) ? 1 : 2;
- const bool is_sd = (header[4] & 0x40) ? true : false;
+ 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);
- auto variant = floppy_image::SSDD;
- if (is_sd)
- {
- if (heads == 2)
- {
- variant = floppy_image::DSSD;
- }
- else
- {
- variant = floppy_image::SSSD;
- }
- }
- else
- {
- if (heads == 2)
- {
- variant = floppy_image::DSDD;
- }
- else
- {
- variant = floppy_image::SSDD;
- }
- }
+ 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);
- int fm_stride = is_sd ? 1 : 2;
+ const int fm_stride = is_sd ? 1 : 2;
for (int track = 0; track < tracks; track++)
{
@@ -155,15 +169,17 @@ bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::ve
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 mark_location[64 * 2 + 1];
+ uint8_t mark_value[64 * 2 + 1];
+ bool mark_is_mfm[64 * 2 + 1];
int iam_location = -1;
// Read track
- io.read_at(header_size + (heads * track + head) * track_size, &track_data[0], track_size, actual);
+ 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*2+1; i++)
+ for (int i = 0; i < 64 * 2 + 1; i++)
{
mark_location[i] = -1;
mark_value[i] = 0xfe;
@@ -174,10 +190,10 @@ bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::ve
// Find IDAM/DAM locations
uint16_t track_header_offset = 0;
uint16_t track_offset = get_u16le(&track_data[track_header_offset]) & 0x3fff;
- bool idam_is_mfm = (track_data[track_header_offset + 1] & 0x80) ? true : false;
+ 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
int mark_offset = idam_is_mfm ? 3 : 0;
@@ -188,11 +204,11 @@ bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::ve
int stride = idam_is_mfm ? 1 : fm_stride;
// Scan for DAM location
- for (int i = track_offset + 10*stride; i < track_offset + 53*stride; i++)
+ for (int i = track_offset + 10 * stride; i < track_offset + 53 * stride; i++)
{
if ((track_data[i] >= 0xf8 && track_data[i] <= 0xfb))
{
- if (!idam_is_mfm || (track_data[i-1] == 0xa1 && track_data[i-2] == 0xa1))
+ 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];
@@ -204,7 +220,7 @@ bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::ve
}
}
- idam_is_mfm = (track_data[track_header_offset + 1] & 0x80) ? true : false;
+ 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;
}
@@ -216,10 +232,10 @@ bool dmk_format::load(util::random_read &io, uint32_t form_factor, const std::ve
}
// Find IAM location
- for(int i = mark_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 && (is_sd || (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 - (is_sd ? 0 : 3);
break;