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author wilbertpol <wilbertpol@users.noreply.github.com>2024-06-02 01:01:46 +0100
committer GitHub <noreply@github.com>2024-06-01 20:01:46 -0400
commit2969f1c6debc0d359082572b6462e7c4b625e878 (patch)
treefbd0485f2bbe00f57da4dc6261c740a0a82a6ac6
parenta0c09745bfd45878dbd691138cdcf5a312f5a645 (diff)
lib/formats/fs_coco_rsdos.cpp: Add basic write support. (#12411)
-rw-r--r--src/lib/formats/fs_coco_rsdos.cpp299
1 files changed, 279 insertions, 20 deletions
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 <bitset>
#include <optional>
+#include <regex>
#include <string_view>
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<err_t, std::vector<dir_entry>> directory_contents(const std::vector<std::string> &path) override;
virtual std::pair<err_t, std::vector<u8>> file_read(const std::vector<std::string> &path) override;
virtual err_t format(const meta_data &meta) override;
+ virtual err_t file_create(const std::vector<std::string> &path, const meta_data &meta) override;
+ virtual err_t file_write(const std::vector<std::string> &path, const std::vector<u8> &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<rsdos_dirent> dirent_from_path(const std::vector<std::string> &path);
- void iterate_directory_entries(const std::function<bool(const rsdos_dirent &dirent)> &callback);
+ template <typename T>
+ 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<err_t, std::string> build_direntry_filename(const std::string &filename);
+ std::pair<err_t, u8> claim_granule();
+ void write_granule_map(u8 granule, u8 map_data);
+ u8 read_granule_map(u8 granule) const;
+ bool is_ascii(const std::vector<u8> &data) const;
+ u8 determine_file_type(const std::vector<u8> &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<err_t, meta_data> coco_rsdos_impl::metadata(const std::vector<std::str
std::pair<err_t, std::vector<dir_entry>> coco_rsdos_impl::directory_contents(const std::vector<std::string> &path)
{
std::vector<dir_entry> 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<err_t, std::vector<u8>> coco_rsdos_impl::file_read(const std::vector<s
// read this sector
auto block = read_sector(track, sector);
const u8 *data = block.rodata();
- u16 data_length = std::min(byte_count, u16(256));
+ u16 data_length = std::min(byte_count, u16(SECTOR_SIZE));
// and append it to the results
memcpy(result.data() + current_size, data, data_length);
@@ -292,6 +325,221 @@ err_t coco_rsdos_impl::format(const meta_data &meta)
}
+std::pair<err_t, std::string> 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<std::string> &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<std::string> &path, const std::vector<u8> &data)
+{
+ if (path.size() != 1)
+ return ERR_NOT_FOUND;
+ const std::string &target = path[0];
+
+ std::optional<rsdos_dirent> 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<u8> &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<u8> &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<err_t, u8> 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::rsdos_dirent> coco_rsdos_impl::dirent_from_path(c
const std::string &target = path[0];
std::optional<rsdos_dirent> 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::rsdos_dirent> coco_rsdos_impl::dirent_from_path(c
// coco_rsdos_impl::iterate_directory_entries
//-------------------------------------------------
-void coco_rsdos_impl::iterate_directory_entries(const std::function<bool(const rsdos_dirent &dirent)> &callback)
+template <typename T>
+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 &sector = *reinterpret_cast<const rsdos_dirent_sector *>(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