mirror of
https://github.com/TomHarte/CLK.git
synced 2024-12-25 18:30:21 +00:00
Started working towards capturing everything there is to know about a file. CRC calculation appears to be flawed somehow at the moment.
This commit is contained in:
Thomas Harte
parent
6218f05b8c
commit
b3521ed187
@ -11,36 +11,33 @@
|
||||
using namespace StaticAnalyser::Acorn;
|
||||
|
||||
struct TapeParser {
|
||||
float wave_lengths[4];
|
||||
int wave_length_pointer;
|
||||
|
||||
TapeParser() : wave_length_pointer(0) {}
|
||||
TapeParser(const std::shared_ptr<Storage::Tape::Tape> &tape) : _wave_length_pointer(0), _tape(tape) {}
|
||||
|
||||
int GetNextBit(const std::shared_ptr<Storage::Tape::Tape> &tape)
|
||||
int get_next_bit()
|
||||
{
|
||||
while(!tape->is_at_end())
|
||||
while(!_tape->is_at_end())
|
||||
{
|
||||
// skip any gaps
|
||||
Storage::Tape::Tape::Pulse next_pulse = tape->get_next_pulse();
|
||||
Storage::Tape::Tape::Pulse next_pulse = _tape->get_next_pulse();
|
||||
while(next_pulse.type == Storage::Tape::Tape::Pulse::Zero)
|
||||
{
|
||||
next_pulse = tape->get_next_pulse();
|
||||
next_pulse = _tape->get_next_pulse();
|
||||
}
|
||||
|
||||
wave_lengths[wave_length_pointer] = next_pulse.length.get_float();
|
||||
wave_length_pointer++;
|
||||
_wave_lengths[_wave_length_pointer] = next_pulse.length.get_float();
|
||||
_wave_length_pointer++;
|
||||
|
||||
// if first wave is too short or too long, drop it
|
||||
if(wave_lengths[0] < 1.0f / 4800.0f || wave_lengths[0] >= 5.0f / 4800.0f)
|
||||
if(_wave_lengths[0] < 1.0f / 4800.0f || _wave_lengths[0] >= 5.0f / 4800.0f)
|
||||
{
|
||||
rotate(1);
|
||||
continue;
|
||||
}
|
||||
|
||||
// if first two waves add up to a correct-length cycle, pop them and this is a 0
|
||||
if(wave_length_pointer >= 2)
|
||||
if(_wave_length_pointer >= 2)
|
||||
{
|
||||
float length = wave_lengths[0] + wave_lengths[1];
|
||||
float length = _wave_lengths[0] + _wave_lengths[1];
|
||||
if(length >= 3.0f / 4800.0f && length < 5.0f / 4800.0f)
|
||||
{
|
||||
rotate(2);
|
||||
@ -49,70 +46,165 @@ struct TapeParser {
|
||||
}
|
||||
|
||||
// if all four waves add up to a correct-length cycle, pop them and this is a 1
|
||||
if(wave_length_pointer >= 4)
|
||||
if(_wave_length_pointer == 4)
|
||||
{
|
||||
float length = wave_lengths[0] + wave_lengths[1] + wave_lengths[2] + wave_lengths[3];
|
||||
float length = _wave_lengths[0] + _wave_lengths[1] + _wave_lengths[2] + _wave_lengths[3];
|
||||
if(length >= 3.0f / 4800.0f && length < 5.0f / 4800.0f)
|
||||
{
|
||||
rotate(4);
|
||||
return 1;
|
||||
}
|
||||
else
|
||||
{
|
||||
rotate(1);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int GetNextByte(const std::shared_ptr<Storage::Tape::Tape> &tape)
|
||||
int get_next_byte()
|
||||
{
|
||||
int value = 0;
|
||||
int c = 8;
|
||||
if(GetNextBit(tape)) return -1;
|
||||
if(get_next_bit())
|
||||
{
|
||||
_error_flag = true;
|
||||
return -1;
|
||||
}
|
||||
while(c--)
|
||||
{
|
||||
value = (value >> 1) | (GetNextBit(tape) << 7);
|
||||
value = (value >> 1) | (get_next_bit() << 7);
|
||||
}
|
||||
if(!GetNextBit(tape)) return -1;
|
||||
if(!get_next_bit())
|
||||
{
|
||||
_error_flag = true;
|
||||
return -1;
|
||||
}
|
||||
add_to_crc((uint8_t)value);
|
||||
return value;
|
||||
}
|
||||
|
||||
int get_next_short()
|
||||
{
|
||||
int result = get_next_byte();
|
||||
result |= get_next_byte() << 8;
|
||||
return result;
|
||||
}
|
||||
|
||||
int get_next_word()
|
||||
{
|
||||
int result = get_next_short();
|
||||
result |= get_next_short() << 8;
|
||||
return result;
|
||||
}
|
||||
|
||||
void reset_error_flag()
|
||||
{
|
||||
_error_flag = false;
|
||||
}
|
||||
|
||||
bool get_error_flag()
|
||||
{
|
||||
return _error_flag;
|
||||
}
|
||||
|
||||
void reset_crc()
|
||||
{
|
||||
_crc = 0;
|
||||
}
|
||||
|
||||
void add_to_crc(uint8_t value)
|
||||
{
|
||||
_crc ^= (uint16_t)value << 8;
|
||||
for(int c = 0; c < 8; c++)
|
||||
{
|
||||
uint16_t exclusive_or = (_crc&0x8000) ? 0x1021 : 0x0000;
|
||||
_crc = (uint16_t)(_crc << 1) ^ exclusive_or;
|
||||
}
|
||||
}
|
||||
|
||||
uint16_t get_crc()
|
||||
{
|
||||
return _crc;
|
||||
}
|
||||
|
||||
bool is_at_end()
|
||||
{
|
||||
return _tape->is_at_end();
|
||||
}
|
||||
|
||||
private:
|
||||
void rotate(int places)
|
||||
{
|
||||
wave_length_pointer -= places;
|
||||
if(places < 4) memmove(wave_lengths, &wave_lengths[places], (size_t)(4 - places) * sizeof(float));
|
||||
_wave_length_pointer -= places;
|
||||
if(places < 4) memmove(_wave_lengths, &_wave_lengths[places], (size_t)(4 - places) * sizeof(float));
|
||||
}
|
||||
|
||||
|
||||
uint16_t _crc;
|
||||
bool _error_flag;
|
||||
|
||||
float _wave_lengths[4];
|
||||
int _wave_length_pointer;
|
||||
std::shared_ptr<Storage::Tape::Tape> _tape;
|
||||
};
|
||||
|
||||
std::unique_ptr<File> StaticAnalyser::Acorn::GetNextFile(const std::shared_ptr<Storage::Tape::Tape> &tape)
|
||||
static std::unique_ptr<File::Chunk> GetNextChunk(TapeParser &parser)
|
||||
{
|
||||
std::unique_ptr<File::Chunk> new_chunk(new File::Chunk);
|
||||
int shift_register = 0;
|
||||
TapeParser parser;
|
||||
|
||||
#define shift() \
|
||||
shift_register = (shift_register >> 1) | (parser.GetNextBit(tape) << 9)
|
||||
shift_register = (shift_register >> 1) | (parser.get_next_bit() << 9)
|
||||
|
||||
// find next area of high tone
|
||||
while(!tape->is_at_end() && (shift_register != 0x3ff))
|
||||
while(!parser.is_at_end() && (shift_register != 0x3ff))
|
||||
{
|
||||
shift();
|
||||
}
|
||||
|
||||
// find next 0x2a (swallowing stop bit)
|
||||
while(!tape->is_at_end() && (shift_register != 0x254))
|
||||
while(!parser.is_at_end() && (shift_register != 0x254))
|
||||
{
|
||||
shift();
|
||||
}
|
||||
|
||||
parser.reset_crc();
|
||||
parser.reset_error_flag();
|
||||
|
||||
// read out name
|
||||
char name[10];
|
||||
int name_ptr = 0;
|
||||
while(!tape->is_at_end() && name_ptr < 10)
|
||||
while(!parser.is_at_end() && name_ptr < 10)
|
||||
{
|
||||
name[name_ptr] = (char)parser.GetNextByte(tape);
|
||||
name[name_ptr] = (char)parser.get_next_byte();
|
||||
if(!name[name_ptr]) break;
|
||||
name_ptr++;
|
||||
}
|
||||
|
||||
// addresses
|
||||
new_chunk->load_address = (uint32_t)parser.get_next_word();
|
||||
new_chunk->execution_address = (uint32_t)parser.get_next_word();
|
||||
new_chunk->block_number = (uint16_t)parser.get_next_short();
|
||||
new_chunk->block_length = (uint16_t)parser.get_next_short();
|
||||
new_chunk->block_flag = (uint8_t)parser.get_next_byte();
|
||||
new_chunk->next_address = (uint32_t)parser.get_next_word();
|
||||
|
||||
uint16_t calculated_crc = parser.get_crc();
|
||||
uint16_t stored_crc = (uint16_t)parser.get_next_short();
|
||||
|
||||
printf("%04x v %04x", calculated_crc, stored_crc);
|
||||
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
std::unique_ptr<File> StaticAnalyser::Acorn::GetNextFile(const std::shared_ptr<Storage::Tape::Tape> &tape)
|
||||
{
|
||||
TapeParser parser(tape);
|
||||
|
||||
GetNextChunk(parser);
|
||||
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
@ -9,6 +9,7 @@
|
||||
#ifndef StaticAnalyser_Acorn_Tape_hpp
|
||||
#define StaticAnalyser_Acorn_Tape_hpp
|
||||
|
||||
#include <list>
|
||||
#include <memory>
|
||||
#include <string>
|
||||
#include <vector>
|
||||
@ -20,10 +21,25 @@ namespace Acorn {
|
||||
|
||||
struct File {
|
||||
std::string name;
|
||||
uint16_t load_address;
|
||||
uint16_t execution_address;
|
||||
uint32_t load_address;
|
||||
uint32_t execution_address;
|
||||
bool is_protected;
|
||||
std::vector<uint8_t> data;
|
||||
|
||||
struct Chunk {
|
||||
uint32_t load_address;
|
||||
uint32_t execution_address;
|
||||
uint16_t block_number;
|
||||
uint16_t block_length;
|
||||
uint8_t block_flag;
|
||||
uint32_t next_address;
|
||||
|
||||
bool header_crc_matched;
|
||||
bool data_crc_matched;
|
||||
std::vector<uint8_t> data;
|
||||
};
|
||||
|
||||
std::list<Chunk> chunks;
|
||||
};
|
||||
|
||||
std::unique_ptr<File> GetNextFile(const std::shared_ptr<Storage::Tape::Tape> &tape);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user