Method mount

lib/vfs/microdos.cc:166–197

private:
    void mount()
    {
        _rootBlock = getLogicalSector(0);
        _catBlock = getLogicalSector(9);
        Bytes directory = getLogicalSector(1, 8);

        ByteReader rbr(_rootBlock);
        rbr.seek(20);
        _volumeLabel = trimWhitespace(rbr.read(44));

        _dirents.clear();
        ByteReader dbr(directory);
        while (!dbr.eof())
        {
            Bytes direntBytes = dbr.read(16);
            if ((direntBytes[0] != 0) && (direntBytes[0] != 0xff))
            {
                auto dirent =
                    std::make_unique<MicrodosDirent>(*this, direntBytes);
                _dirents.push_back(std::move(dirent));
            }
        }

        ByteReader cbr(_catBlock);
        _totalBlocks = 630;
        _usedBlocks = 0;
        for (int i = 0; i < _totalBlocks / 8; i++)
        {
            uint8_t b = cbr.read_8();
            _usedBlocks += countSetBits(b);
        }
    }

    std::shared_ptr<MicrodosDirent> findFile(const std::string filename)
    {