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Adds support for raw sector dumps.

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This commit is contained in:
Thomas Harte 2019-06-18 14:14:25 -04:00
parent 506276a2bd
commit 9730800b6a
1 changed files with 69 additions and 41 deletions
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110
Storage/Disk/DiskImage/Formats/DiskCopy42.cpp
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@ -22,6 +22,14 @@ using namespace Storage::Disk;
DiskCopy42::DiskCopy42(const std::string &file_name) :
file_(file_name) {
// Test 1: is this a raw secctor dump? If so it'll start with
// the magic word 0x4C4B6000 (big endian) and be exactly
// 819,200 bytes long if double sided, or 409,600 bytes if
// single sided.
//
// Luckily, 0x4c is an invalid string length for the proper
// DiskCopy 4.2 format, so there's no ambiguity here.
// File format starts with 64 bytes dedicated to the disk name;
// this is a Pascal-style string though there is apparently a
// bug in one version of Disk Copy that can cause the length to
@ -29,51 +37,71 @@ DiskCopy42::DiskCopy42(const std::string &file_name) :
//
// Validate the length, then skip the rest of the string.
const auto name_length = file_.get8();
if(name_length > 64)
throw Error::InvalidFormat;
if(name_length == 0x4c) {
if(file_.stats().st_size != 819200 && file_.stats().st_size != 409600)
throw Error::InvalidFormat;
// Get the length of the data and tag blocks.
file_.seek(64, SEEK_SET);
const auto data_block_length = file_.get32be();
const auto tag_block_length = file_.get32be();
const auto data_checksum = file_.get32be();
const auto tag_checksum = file_.get32be();
uint32_t magic_word = file_.get24be();
if(magic_word != 0x4b6000)
throw Error::InvalidFormat;
// Don't continue with no data.
if(!data_block_length)
throw Error::InvalidFormat;
file_.seek(0, SEEK_SET);
if(file_.stats().st_size == 819200) {
encoding_ = Encoding::GCR800;
format_ = 0x22;
data_ = file_.read(819200);
} else {
encoding_ = Encoding::GCR400;
format_ = 0x2;
data_ = file_.read(409600);
}
} else {
if(name_length > 64)
throw Error::InvalidFormat;
// Check that this is a comprehensible disk encoding.
const auto encoding = file_.get8();
switch(encoding) {
default: throw Error::InvalidFormat;
// Get the length of the data and tag blocks.
file_.seek(64, SEEK_SET);
const auto data_block_length = file_.get32be();
const auto tag_block_length = file_.get32be();
const auto data_checksum = file_.get32be();
const auto tag_checksum = file_.get32be();
case 0: encoding_ = Encoding::GCR400; break;
case 1: encoding_ = Encoding::GCR800; break;
case 2: encoding_ = Encoding::MFM720; break;
case 3: encoding_ = Encoding::MFM1440; break;
// Don't continue with no data.
if(!data_block_length)
throw Error::InvalidFormat;
// Check that this is a comprehensible disk encoding.
const auto encoding = file_.get8();
switch(encoding) {
default: throw Error::InvalidFormat;
case 0: encoding_ = Encoding::GCR400; break;
case 1: encoding_ = Encoding::GCR800; break;
case 2: encoding_ = Encoding::MFM720; break;
case 3: encoding_ = Encoding::MFM1440; break;
}
format_ = file_.get8();
// Check the magic number.
const auto magic_number = file_.get16be();
if(magic_number != 0x0100)
throw Error::InvalidFormat;
// Read the data and tags, and verify that enough data
// was present.
data_ = file_.read(data_block_length);
tags_ = file_.read(tag_block_length);
if(data_.size() != data_block_length || tags_.size() != tag_block_length)
throw Error::InvalidFormat;
// Verify the two checksums.
const auto computed_data_checksum = checksum(data_);
const auto computed_tag_checksum = checksum(tags_, 12);
if(computed_tag_checksum != tag_checksum || computed_data_checksum != data_checksum)
throw Error::InvalidFormat;
}
format_ = file_.get8();
// Check the magic number.
const auto magic_number = file_.get16be();
if(magic_number != 0x0100)
throw Error::InvalidFormat;
// Read the data and tags, and verify that enough data
// was present.
data_ = file_.read(data_block_length);
tags_ = file_.read(tag_block_length);
if(data_.size() != data_block_length || tags_.size() != tag_block_length)
throw Error::InvalidFormat;
// Verify the two checksums.
const auto computed_data_checksum = checksum(data_);
const auto computed_tag_checksum = checksum(tags_, 12);
if(computed_tag_checksum != tag_checksum || computed_data_checksum != data_checksum)
throw Error::InvalidFormat;
}
uint32_t DiskCopy42::checksum(const std::vector<uint8_t> &data, size_t bytes_to_skip) {
@ -130,7 +158,7 @@ std::shared_ptr<::Storage::Disk::Track> DiskCopy42::get_track_at_position(::Stor
if(start_sector*512 >= data_.size()) return nullptr;
uint8_t *sector = &data_[512 * start_sector];
uint8_t *tags = tags_.size() ? nullptr : &tags_[12 * start_sector];
uint8_t *tags = tags_.size() ? &tags_[12 * start_sector] : nullptr;
Storage::Disk::PCMSegment segment;
segment += Encodings::AppleGCR::six_and_two_sync(24);