diff --git a/src/lib/formats/fs_coco_rsdos.cpp b/src/lib/formats/fs_coco_rsdos.cpp index 76b737d9011..a4aa15afee2 100644 --- a/src/lib/formats/fs_coco_rsdos.cpp +++ b/src/lib/formats/fs_coco_rsdos.cpp @@ -1,11 +1,14 @@ // license:BSD-3-Clause -// copyright-holders:Nathan Woods +// copyright-holders:Nathan Woods, Wilbert Pol /*************************************************************************** fs_coco_rsdos.cpp Management of CoCo "RS-DOS" floppy images +Limitation: +- The determination of the file type is very limited. + ***************************************************************************/ #include "fs_coco_rsdos.h" @@ -16,6 +19,7 @@ #include #include +#include #include using namespace fs; @@ -30,6 +34,8 @@ public: coco_rsdos_impl(fsblk_t &blockdev); virtual ~coco_rsdos_impl() = default; + static constexpr int SECTOR_DIRECTORY_ENTRY_COUNT = 8; + struct rsdos_dirent { char m_filename[11]; @@ -46,7 +52,7 @@ public: { rsdos_dirent m_dirent; u8 m_unused[16]; - } m_entries[8]; + } m_entries[SECTOR_DIRECTORY_ENTRY_COUNT]; }; class granule_iterator @@ -67,16 +73,43 @@ public: virtual std::pair> directory_contents(const std::vector &path) override; virtual std::pair> file_read(const std::vector &path) override; virtual err_t format(const meta_data &meta) override; + virtual err_t file_create(const std::vector &path, const meta_data &meta) override; + virtual err_t file_write(const std::vector &path, const std::vector &data) override; static bool validate_filename(std::string_view name); private: + static constexpr u8 TRACK_GRANULE_COUNT = 2; + static constexpr u8 GRANULE_SECTOR_COUNT = 9; + static constexpr u8 TRACK_SECTOR_COUNT = TRACK_GRANULE_COUNT * GRANULE_SECTOR_COUNT; + static constexpr u8 DIRECTORY_TRACK = 17; + static constexpr u8 DIRECTORY_ENTRY_SIZE = 0x20; + static constexpr u8 FNAME_LENGTH = 11; + static constexpr u16 SECTOR_SIZE = 0x100; + static constexpr u8 OFFSET_FILE_TYPE = 0x0b; + static constexpr u8 OFFSET_ASCII_FLAG = 0x0c; + static constexpr u8 OFFSET_FIRST_GRANULE = 0x0d; + static constexpr u8 OFFSET_LAST_SECTOR_BYTES = 0x0e; + static constexpr u8 FILE_TYPE_BASIC = 0x00; + static constexpr u8 FILE_TYPE_BASIC_DATA = 0x01; + static constexpr u8 FILE_TYPE_MACHINE_CODE = 0x02; + static constexpr u8 FILE_TYPE_TEXT_EDITOR = 0x03; + static constexpr u8 FILE_LAST_GRANULE_INDICATOR = 0xc0; + fsblk_t::block_t read_sector(int track, int sector) const; + fsblk_t::block_t read_granule_sector(u8 granule, u8 sector) const; u8 maximum_granules() const; std::optional dirent_from_path(const std::vector &path); - void iterate_directory_entries(const std::function &callback); + template + void iterate_directory_entries(T &&callback); meta_data get_metadata_from_dirent(const rsdos_dirent &dirent); static std::string get_filename_from_dirent(const rsdos_dirent &dirent); + std::pair build_direntry_filename(const std::string &filename); + std::pair claim_granule(); + void write_granule_map(u8 granule, u8 map_data); + u8 read_granule_map(u8 granule) const; + bool is_ascii(const std::vector &data) const; + u8 determine_file_type(const std::vector &data) const; }; } // anonymous namespace @@ -139,7 +172,7 @@ bool coco_rsdos_image::can_read() const bool coco_rsdos_image::can_write() const { - return false; + return true; } @@ -197,7 +230,7 @@ bool coco_rsdos_impl::validate_filename(std::string_view name) //------------------------------------------------- coco_rsdos_impl::coco_rsdos_impl(fsblk_t &blockdev) - : filesystem_t(blockdev, 256) + : filesystem_t(blockdev, SECTOR_SIZE) { } @@ -224,7 +257,7 @@ std::pair coco_rsdos_impl::metadata(const std::vector> coco_rsdos_impl::directory_contents(const std::vector &path) { std::vector results; - auto callback = [this, &results](const rsdos_dirent &dirent) + auto const callback = [this, &results](u8 s, u8 i, const rsdos_dirent &dirent) { results.emplace_back(dir_entry_type::file, get_metadata_from_dirent(dirent)); return false; @@ -265,7 +298,7 @@ std::pair> coco_rsdos_impl::file_read(const std::vector coco_rsdos_impl::build_direntry_filename(const std::string &filename) +{ + // The manual does not say anything about valid characters for a file name. + const std::regex filename_regex("([^.]{0,8})(\\.([^.]{0,3}))?"); + std::smatch smatch; + if (!std::regex_match(filename, smatch, filename_regex)) + return std::make_pair(ERR_INVALID, std::string()); + if (smatch.size() != 4) + return std::make_pair(ERR_INVALID, std::string()); + + std::string fname; + fname.resize(FNAME_LENGTH, ' '); + + for (int i = 0; i < 8 && i < smatch.str(1).size(); i++) + fname[i] = smatch.str(1)[i]; + + for (int j = 0; j < 3 && j < smatch.str(3).size(); j++) + fname[8 + j] = smatch.str(3)[j]; + + return std::make_pair(ERR_OK, std::move(fname)); +} + + +err_t coco_rsdos_impl::file_create(const std::vector &path, const meta_data &meta) +{ + if (!path.empty()) + return ERR_UNSUPPORTED; + + const std::string filename = meta.get_string(meta_name::name, ""); + auto [err, fname] = build_direntry_filename(filename); + if (err != ERR_OK) + return err; + + bool found_entry = false; + u8 dir_sector = 0; + u8 file_index = 0; + for (dir_sector = 3; !found_entry && dir_sector <= TRACK_SECTOR_COUNT; dir_sector++) + { + auto dir_block = read_sector(DIRECTORY_TRACK, dir_sector); + + for (file_index = 0; !found_entry && file_index < SECTOR_DIRECTORY_ENTRY_COUNT; file_index++) + { + const u8 first_byte = dir_block.r8(file_index * DIRECTORY_ENTRY_SIZE); + // 0xff marks the end of the directory, 0x00 marks a deleted file + found_entry = (first_byte == 0xff || first_byte == 0x00); + if (found_entry) + { + for (int i = 0; i < DIRECTORY_ENTRY_SIZE; i++) + dir_block.w8(file_index * DIRECTORY_ENTRY_SIZE + i, 0); + + auto [cerr, granule] = claim_granule(); + if (cerr != ERR_OK) + return cerr; + + dir_block.wstr(file_index * DIRECTORY_ENTRY_SIZE + 0, fname); + dir_block.w8(file_index * DIRECTORY_ENTRY_SIZE + OFFSET_FIRST_GRANULE, granule); + // The file type, ascii flag, and number of bytes in last sector of file will be set during writing. + } + } + } + if (!found_entry) + return ERR_NO_SPACE; + + return ERR_OK; +} + + +err_t coco_rsdos_impl::file_write(const std::vector &path, const std::vector &data) +{ + if (path.size() != 1) + return ERR_NOT_FOUND; + const std::string &target = path[0]; + + std::optional result; + u8 dir_sector = 0; + u8 dir_file_index = 0; + auto const callback = [&result, &target, &dir_sector, &dir_file_index](u8 s, u8 i, const rsdos_dirent &dirent) + { + const bool found = get_filename_from_dirent(dirent) == target; + if (found) + { + result = dirent; + dir_sector = s; + dir_file_index = i; + } + return found; + }; + iterate_directory_entries(callback); + + if (!result) + return ERR_NOT_FOUND; + + const size_t data_length = data.size(); + const u8 max_granule = maximum_granules(); + u8 granule = result->m_first_granule; + u8 granule_sector = 1; + size_t offset = 0; + u16 bytes_in_last_sector = 0; + u8 linked_granule = read_granule_map(granule); + + while (offset < data_length) + { + auto data_block = read_granule_sector(granule, granule_sector); + bytes_in_last_sector = (data_length - offset) > SECTOR_SIZE ? SECTOR_SIZE : data_length - offset; + memcpy(data_block.data(), data.data() + offset, bytes_in_last_sector); + offset += SECTOR_SIZE; + write_granule_map(granule, FILE_LAST_GRANULE_INDICATOR + granule_sector); + if (offset < data_length) + { + granule_sector++; + if (granule_sector > GRANULE_SECTOR_COUNT) + { + // Re-use linked granule or claim a new granule + if (linked_granule < max_granule) + { + granule = linked_granule; + linked_granule = read_granule_map(linked_granule); + } + else + { + auto [err, next_granule] = claim_granule(); + if (err != ERR_OK) + return err; + write_granule_map(granule, next_granule); + granule = next_granule; + } + granule_sector = 1; + } + } + } + + // Free unused space + while (linked_granule < max_granule) + { + const u8 granule_to_free = linked_granule; + linked_granule = read_granule_map(granule_to_free); + write_granule_map(granule_to_free, 0xff); + } + + // Update directory entry + auto dir_block = read_sector(DIRECTORY_TRACK, dir_sector); + dir_block.w8(dir_file_index * DIRECTORY_ENTRY_SIZE + OFFSET_FILE_TYPE, determine_file_type(data)); + dir_block.w8(dir_file_index * DIRECTORY_ENTRY_SIZE + OFFSET_ASCII_FLAG, is_ascii(data) ? 0xff : 0x00); + dir_block.w16b(dir_file_index * DIRECTORY_ENTRY_SIZE + OFFSET_LAST_SECTOR_BYTES, bytes_in_last_sector); + + return ERR_OK; +} + + +bool coco_rsdos_impl::is_ascii(const std::vector &data) const +{ + const size_t data_length = data.size(); + + if (data_length == 0) + return false; + + for (int i = 0; i < data_length; i++) + { + if (!(data[i] == 0x0d || data[i] == 0x0a || (data[i] >= 0x20 && data[i] < 0x60))) + return false; + } + + return true; +} + + +u8 coco_rsdos_impl::determine_file_type(const std::vector &data) const +{ + if (is_ascii(data)) + { + // TODO: Distinguish between basic code and text editor data + return FILE_TYPE_BASIC; + } + + const size_t data_length = data.size(); + // Binary basic code seems to begin with ff <16bit size> 26 + if (data_length > 4 && data[0] == 0xff && data[3] == 0x26 && ((data[1] << 8) | data[2]) == data_length - 3) + return FILE_TYPE_BASIC; + + // TODO: Distinguish between Machine Code and Basic Data + + return FILE_TYPE_MACHINE_CODE; +} + + +std::pair coco_rsdos_impl::claim_granule() +{ + // Granules are likely not assigned in this order on hardware. + auto granule_block = read_sector(DIRECTORY_TRACK, 2); + for (int g = 0; g < maximum_granules(); g++) + { + if (granule_block.r8(g) == 0xff) + { + granule_block.w8(g, FILE_LAST_GRANULE_INDICATOR); + return std::make_pair(ERR_OK, g); + } + } + return std::make_pair(ERR_NO_SPACE, 0); +} + + +void coco_rsdos_impl::write_granule_map(u8 granule, u8 map_data) +{ + auto granule_block = read_sector(DIRECTORY_TRACK, 2); + granule_block.w8(granule, map_data); +} + + +u8 coco_rsdos_impl::read_granule_map(u8 granule) const +{ + auto granule_block = read_sector(DIRECTORY_TRACK, 2); + return granule_block.r8(granule); +} + + //------------------------------------------------- // fsblk_t::block_t coco_rsdos_impl::read_sector //------------------------------------------------- @@ -300,7 +548,17 @@ fsblk_t::block_t coco_rsdos_impl::read_sector(int track, int sector) const { // the CoCo RS-DOS world thinks in terms of tracks/sectors, but we have a block device // abstraction - return m_blockdev.get(track * 18 + sector - 1); + return m_blockdev.get(track * TRACK_SECTOR_COUNT + sector - 1); +} + + +fsblk_t::block_t coco_rsdos_impl::read_granule_sector(u8 granule, u8 sector) const +{ + // Track 17 does not hold granules + if (granule < (DIRECTORY_TRACK * TRACK_GRANULE_COUNT)) + return m_blockdev.get(granule * GRANULE_SECTOR_COUNT + sector - 1); + else + return m_blockdev.get((granule + TRACK_GRANULE_COUNT) * GRANULE_SECTOR_COUNT + sector - 1); } @@ -311,7 +569,7 @@ fsblk_t::block_t coco_rsdos_impl::read_sector(int track, int sector) const u8 coco_rsdos_impl::maximum_granules() const { u32 sector_count = m_blockdev.block_count(); - u32 granule_count = (sector_count / 9) - 2; + u32 granule_count = (sector_count / GRANULE_SECTOR_COUNT) - 2; return granule_count <= 0xFF ? u8(granule_count) : 0xFF; } @@ -327,7 +585,7 @@ std::optional coco_rsdos_impl::dirent_from_path(c const std::string &target = path[0]; std::optional result; - auto callback = [&result, &target](const rsdos_dirent &dirent) + auto const callback = [&result, &target](u8 s, u8 i, const rsdos_dirent &dirent) { bool found = get_filename_from_dirent(dirent) == target; if (found) @@ -343,28 +601,29 @@ std::optional coco_rsdos_impl::dirent_from_path(c // coco_rsdos_impl::iterate_directory_entries //------------------------------------------------- -void coco_rsdos_impl::iterate_directory_entries(const std::function &callback) +template +void coco_rsdos_impl::iterate_directory_entries(T &&callback) { bool done = false; for (int dir_sector = 3; !done && dir_sector <= 18; dir_sector++) { // read this directory sector - auto dir_block = read_sector(17, dir_sector); + auto dir_block = read_sector(DIRECTORY_TRACK, dir_sector); const rsdos_dirent_sector §or = *reinterpret_cast(dir_block.rodata()); // and loop through all entries - for (const auto &ent : sector.m_entries) + for (int file_index = 0; file_index < 8; file_index++) { // 0xFF marks the end of the directory - if (ent.m_dirent.m_filename[0] == '\xFF') + if (sector.m_entries[file_index].m_dirent.m_filename[0] == '\xFF') { done = true; } else { // 0x00 marks a deleted file - if (ent.m_dirent.m_filename[0] != '\0') - done = callback(ent.m_dirent); + if (sector.m_entries[file_index].m_dirent.m_filename[0] != '\0') + done = callback(dir_sector, 0, sector.m_entries[file_index].m_dirent); } if (done) @@ -427,7 +686,7 @@ std::string coco_rsdos_impl::get_filename_from_dirent(const rsdos_dirent &dirent //------------------------------------------------- coco_rsdos_impl::granule_iterator::granule_iterator(coco_rsdos_impl &fs, const rsdos_dirent &dirent) - : m_granule_map(fs.read_sector(17, 2)) + : m_granule_map(fs.read_sector(DIRECTORY_TRACK, 2)) , m_current_granule(dirent.m_first_granule) , m_maximum_granules(fs.maximum_granules()) , m_last_sector_bytes((u16(dirent.m_last_sector_bytes_msb) << 8) | dirent.m_last_sector_bytes_lsb) @@ -456,7 +715,7 @@ bool coco_rsdos_impl::granule_iterator::next(u8 &granule, u16 &byte_count) // this entry points to the next granule success = true; granule = *m_current_granule; - byte_count = 9 * 256; + byte_count = GRANULE_SECTOR_COUNT * SECTOR_SIZE; next_granule = granule_map_data[*m_current_granule]; // check for cycles, which should only happen if the disk is corrupt (or not in RS-DOS format) @@ -465,13 +724,13 @@ bool coco_rsdos_impl::granule_iterator::next(u8 &granule, u16 &byte_count) else m_visited_granules.set(*next_granule); } - else if (granule_map_data[*m_current_granule] >= 0xC0 && granule_map_data[*m_current_granule] <= 0xC9) + else if (granule_map_data[*m_current_granule] >= FILE_LAST_GRANULE_INDICATOR && granule_map_data[*m_current_granule] <= FILE_LAST_GRANULE_INDICATOR + GRANULE_SECTOR_COUNT) { // this is the last granule in the file success = true; granule = *m_current_granule; u16 sector_count = std::max(granule_map_data[*m_current_granule], u8(0xC1)) - 0xC1; - byte_count = sector_count * 256 + m_last_sector_bytes; + byte_count = sector_count * SECTOR_SIZE + m_last_sector_bytes; next_granule = std::nullopt; } else