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Merge pull request #192 from TomHarte/PerDriveStatus

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Expands 8272 emulation further
This commit is contained in:
Thomas Harte 2017-08-12 16:49:06 -04:00 committed by GitHub
commit e7345c7a20
3 changed files with 156 additions and 57 deletions
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156
Components/8272/i8272.cpp
View File

@ -17,10 +17,6 @@ const uint8_t StatusRequest = 0x80; // Set: ready to send or receive from proces
const uint8_t StatusDirection = 0x40; // Set: data is expected to be taken from the 8272 by the processor.
const uint8_t StatusNonDMAExecuting = 0x20; // Set: the execution phase of a data transfer command is ongoing and DMA mode is disabled.
const uint8_t StatusBusy = 0x10; // Set: the FDC is busy.
//const uint8_t StatusD3B = 0x08; // Set: drive 3 is seeking.
//const uint8_t StatusD2B = 0x04; // Set: drive 2 is seeking.
//const uint8_t StatusD1B = 0x02; // Set: drive 1 is seeking.
//const uint8_t StatusD0B = 0x01; // Set: drive 0 is seeking.
}
i8272::i8272(Cycles clock_rate, int clock_rate_multiplier, int revolutions_per_minute) :
@ -29,7 +25,7 @@ i8272::i8272(Cycles clock_rate, int clock_rate_multiplier, int revolutions_per_m
interesting_event_mask_((int)Event8272::CommandByte),
resume_point_(0),
delay_time_(0),
status_{0, 0, 0} {
head_timers_running_(0) {
posit_event((int)Event8272::CommandByte);
}
@ -60,7 +56,7 @@ void i8272::run_for(Cycles cycles) {
drives_[c].head_position += direction;
// Check for completion.
if(seek_is_satisfied(c)) {
if(drives_[c].seek_is_satisfied()) {
drives_[c].phase = Drive::CompletedSeeking;
if(drives_[c].target_head_position == -1) drives_[c].head_position = 0;
break;
@ -69,6 +65,24 @@ void i8272::run_for(Cycles cycles) {
}
}
}
// check for any head unloads
if(head_timers_running_) {
for(int c = 0; c < 4; c++) {
for(int h = 0; h < 2; h++) {
if(drives_[c].head_unload_delay[c] > 0) {
if(cycles.as_int() >= drives_[c].head_unload_delay[c]) {
drives_[c].head_unload_delay[c] = 0;
drives_[c].head_is_loaded[c] = false;
head_timers_running_--;
if(!head_timers_running_) return;
} else {
drives_[c].head_unload_delay[c] -= cycles.as_int();
}
}
}
}
}
}
void i8272::set_register(int address, uint8_t value) {
@ -108,7 +122,9 @@ void i8272::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
#define BEGIN_SECTION() switch(resume_point_) { default:
#define END_SECTION() }
#define MS_TO_CYCLES(x) x * 8000
#define WAIT_FOR_EVENT(mask) resume_point_ = __LINE__; interesting_event_mask_ = (int)mask; return; case __LINE__:
#define WAIT_FOR_TIME(ms) resume_point_ = __LINE__; interesting_event_mask_ = (int)Event8272::Timer; delay_time_ = MS_TO_CYCLES(ms); case __LINE__: if(delay_time_) return;
#define PASTE(x, y) x##y
#define CONCAT(x, y) PASTE(x, y)
@ -123,7 +139,7 @@ void i8272::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
#define FIND_DATA() \
CONCAT(find_data, __LINE__): WAIT_FOR_EVENT((int)Event::Token | (int)Event::IndexHole); \
if(event_type == (int)Event::Token && get_latest_token().type != Token::Data) goto CONCAT(find_data, __LINE__);
if(event_type == (int)Event::Token && get_latest_token().type != Token::Data && get_latest_token().type != Token::DeletedData) goto CONCAT(find_data, __LINE__);
#define READ_HEADER() \
distance_into_section_ = 0; \
@ -134,12 +150,37 @@ void i8272::set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive) {
if(distance_into_section_ < 6) goto CONCAT(read_header, __LINE__); \
set_data_mode(Scanning);
#define CLEAR_STATUS() \
status_[0] = status_[1] = status_[2] = 0;
#define SET_DRIVE_HEAD_MFM() \
if(!dma_mode_) main_status_ |= StatusNonDMAExecuting; \
set_drive(drives_[command_[1]&3].drive); \
active_drive_ = command_[1]&3; \
active_head_ = (command_[1] >> 2)&1; \
set_drive(drives_[active_drive_].drive); \
drives_[active_drive_].drive->set_head((unsigned int)active_head_); \
set_is_double_density(command_[0] & 0x40); \
invalidate_track();
#define LOAD_HEAD() \
if(!drives_[active_drive_].head_is_loaded[active_head_]) { \
drives_[active_drive_].head_is_loaded[active_head_] = true; \
WAIT_FOR_TIME(head_load_time_); \
} else { \
if(drives_[active_drive_].head_unload_delay[active_head_] > 0) { \
drives_[active_drive_].head_unload_delay[active_head_] = 0; \
head_timers_running_--; \
} \
}
#define SCHEDULE_HEAD_UNLOAD() \
if(drives_[active_drive_].head_is_loaded[active_head_]) {\
if(drives_[active_drive_].head_unload_delay[active_head_] == 0) { \
head_timers_running_++; \
} \
drives_[active_drive_].head_unload_delay[active_head_] = MS_TO_CYCLES(head_unload_time_);\
}
void i8272::posit_event(int event_type) {
if(!(interesting_event_mask_ & event_type)) return;
interesting_event_mask_ &= ~event_type;
@ -163,14 +204,10 @@ void i8272::posit_event(int event_type) {
switch(command_[0] & 0x1f) {
case 0x06: // read data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
main_status_ &= ~StatusRequest;
goto read_data;
case 0x0b: // read deleted data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
main_status_ &= ~StatusRequest;
goto read_deleted_data;
goto read_data;
case 0x05: // write data
if(command_.size() < 9) goto wait_for_complete_command_sequence;
@ -241,14 +278,15 @@ void i8272::posit_event(int event_type) {
goto invalid;
}
// Performs the read data command.
// Performs the read data or read deleted data command.
read_data:
printf("Read data, sector %02x %02x %02x %02x\n", command_[2], command_[3], command_[4], command_[5]);
printf("Read [deleted?] data, sector %02x %02x %02x %02x\n", command_[2], command_[3], command_[4], command_[5]);
// Establishes the drive and head being addressed, and whether in double density mode; populates the internal
// cylinder, head, sector and size registers from the command stream.
status_[0] = status_[1] = status_[2] = 0;
SET_DRIVE_HEAD_MFM();
LOAD_HEAD();
CLEAR_STATUS();
cylinder_ = command_[2];
head_ = command_[3];
sector_ = command_[4];
@ -262,13 +300,31 @@ void i8272::posit_event(int event_type) {
index_hole_limit_ = 2;
find_next_sector:
FIND_HEADER();
if(!index_hole_limit_) goto read_data_not_found;
if(!index_hole_limit_) {
// Two index holes have passed wihout finding the header sought.
status_[1] |= 0x4;
goto abort_read;
}
READ_HEADER();
if(get_crc_generator().get_value()) {
// This implies a CRC error in the header; mark as such but continue.
status_[1] |= 0x20;
}
if(header_[0] != cylinder_ || header_[1] != head_ || header_[2] != sector_ || header_[3] != size_) goto find_next_sector;
// Finds the next data block and sets data mode to reading.
// Finds the next data block and sets data mode to reading, setting an error flag if the on-disk deleted
// flag doesn't match the sort the command was looking for.
FIND_DATA();
distance_into_section_ = 0;
if((get_latest_token().type == Token::Data) != ((command_[0]&0xf) == 0x6)) {
if(!(command_[0]&0x20)) {
// SK is not set; set the error flag but read this sector before finishing.
status_[2] |= 0x40;
} else {
// SK is set; skip this sector.
goto read_next_data;
}
}
set_data_mode(Reading);
// Waits for the next token, then supplies it to the CPU by: (i) setting data request and direction; and (ii) resetting
@ -281,16 +337,33 @@ void i8272::posit_event(int event_type) {
result_stack_.push_back(get_latest_token().byte_value);
distance_into_section_++;
main_status_ |= StatusRequest | StatusDirection;
WAIT_FOR_EVENT(Event8272::ResultEmpty);
main_status_ &= ~StatusRequest;
if(distance_into_section_ < (128 << size_)) goto get_byte;
WAIT_FOR_EVENT((int)Event8272::ResultEmpty | (int)Event::Token | (int)Event::IndexHole);
switch(event_type) {
case (int)Event8272::ResultEmpty: // The caller read the byte in time; proceed as normal.
main_status_ &= ~StatusRequest;
if(distance_into_section_ < (128 << size_)) goto get_byte;
break;
case (int)Event::Token: // The caller hasn't read the old byte yet and a new one has arrived
status_[0] |= 0x10;
goto abort_read;
break;
case (int)Event::IndexHole:
break;
}
// read CRC, without transferring it
// read CRC, without transferring it, then check it
WAIT_FOR_EVENT(Event::Token);
WAIT_FOR_EVENT(Event::Token);
if(get_crc_generator().get_value()) {
// This implies a CRC error in the sector; mark as such and temrinate.
status_[1] |= 0x20;
status_[2] |= 0x20;
goto abort_read;
}
// check whether that's it
if(sector_ != command_[6]) {
// check whether that's it: either the final requested sector has been read, or because
// a sector that was [/wasn't] marked as deleted when it shouldn't [/should] have been
if(sector_ != command_[6] && !(status_[2]&0x40)) {
sector_++;
goto read_next_data;
}
@ -298,19 +371,10 @@ void i8272::posit_event(int event_type) {
// For a final result phase, post the standard ST0, ST1, ST2, C, H, R, N
goto post_st012chrn;
// Execution reaches here if two index holes were discovered before a matching sector — i.e. the data wasn't found.
// In that case set appropriate error flags and post the results.
read_data_not_found:
printf("Not found\n");
status_[1] |= 0x4;
status_[0] = 0x40; // (status_[0] & ~0xc0) |
abort_read:
status_[0] = 0x40;
goto post_st012chrn;
read_deleted_data:
printf("Read deleted data unimplemented!!\n");
goto wait_for_command;
write_data:
printf("Write data unimplemented!!\n");
goto wait_for_command;
@ -328,13 +392,17 @@ void i8272::posit_event(int event_type) {
// Establishes the drive and head being addressed, and whether in double density mode.
printf("Read ID\n");
SET_DRIVE_HEAD_MFM();
LOAD_HEAD();
// Sets a maximum index hole limit of 2 then waits either until it finds a header mark or sees too many index holes.
// If a header mark is found, reads in the following bytes that produce a header. Otherwise branches to data not found.
index_hole_limit_ = 2;
read_id_find_next_sector:
FIND_HEADER();
if(!index_hole_limit_) goto read_data_not_found;
if(!index_hole_limit_) {
status_[1] |= 0x4;
goto abort_read;
}
READ_HEADER();
// Sets internal registers from the discovered header and posts the standard ST0, ST1, ST2, C, H, R, N.
@ -372,15 +440,15 @@ void i8272::posit_event(int event_type) {
// a recalibrate the target is -1 and ::run_for knows that -1 means the terminal condition is the drive
// returning that its at track zero, and that it should reset the drive's current position once reached.
if(drives_[command_[1]&3].phase != Drive::Seeking) {
status_[0] = status_[1] = status_[2] = 0;
int drive = command_[1]&3;
drives_[drive].phase = Drive::Seeking;
drives_[drive].steps_taken = 0;
drives_[drive].target_head_position = (command_.size() > 2) ? command_[2] : -1;
drives_[drive].step_rate_counter = 0;
drives_[drive].seek_failed = false;
// Check whether any steps are even needed.
if(seek_is_satisfied(drive)) {
if(drives_[drive].seek_is_satisfied()) {
drives_[drive].phase = Drive::CompletedSeeking;
} else {
main_status_ |= 1 << (command_[1]&3);
@ -439,12 +507,14 @@ void i8272::posit_event(int event_type) {
// Performs any invalid command.
invalid:
// A no-op, but posts ST0.
result_stack_.push_back(status_[0]);
// A no-op, but posts ST0 (but which ST0?)
result_stack_.push_back(0x80);
goto post_result;
// Posts ST0, ST1, ST2, C, H, R and N as a result phase.
post_st012chrn:
SCHEDULE_HEAD_UNLOAD();
result_stack_.push_back(size_);
result_stack_.push_back(sector_);
result_stack_.push_back(head_);
@ -474,7 +544,7 @@ void i8272::posit_event(int event_type) {
END_SECTION()
}
bool i8272::seek_is_satisfied(int drive) {
return (drives_[drive].target_head_position == drives_[drive].head_position) ||
(drives_[drive].target_head_position == -1 && drives_[drive].drive->get_is_track_zero());
bool i8272::Drive::seek_is_satisfied() {
return (target_head_position == head_position) ||
(target_head_position == -1 && drive->get_is_track_zero());
}

47
Components/8272/i8272.hpp
View File

@ -29,52 +29,81 @@ class i8272: public Storage::Disk::MFMController {
void set_disk(std::shared_ptr<Storage::Disk::Disk> disk, int drive);
private:
void posit_event(int type);
// Status registers.
uint8_t main_status_;
uint8_t status_[3];
// A buffer for accumulating the incoming command, and one for accumulating the result.
std::vector<uint8_t> command_;
std::vector<uint8_t> result_stack_;
// Event stream: the 8272-specific events, plus the current event state.
enum class Event8272: int {
CommandByte = (1 << 3),
Timer = (1 << 4),
ResultEmpty = (1 << 5),
};
void posit_event(int type);
int interesting_event_mask_;
int resume_point_;
// The counter used for ::Timer events.
int delay_time_;
int step_rate_time_;
int head_unload_time_;
int head_load_time_;
bool dma_mode_;
// The connected drives.
struct Drive {
uint8_t head_position;
// Seeking: persistent state.
enum Phase {
NotSeeking,
Seeking,
CompletedSeeking
} phase;
bool seek_failed;
// Seeking: transient state.
int step_rate_counter;
int steps_taken;
int target_head_position; // either an actual number, or -1 to indicate to step until track zero
/// @returns @c true if the currently queued-up seek or recalibrate has reached where it should be.
bool seek_is_satisfied();
// Head state.
int head_unload_delay[2];
bool head_is_loaded[2];
// The connected drive.
std::shared_ptr<Storage::Disk::Drive> drive;
Drive() : head_position(0), phase(NotSeeking), drive(new Storage::Disk::Drive) {};
Drive() :
head_position(0), phase(NotSeeking),
drive(new Storage::Disk::Drive),
head_is_loaded{false, false} {};
} drives_[4];
// User-supplied parameters; as per the specify command.
int step_rate_time_;
int head_unload_time_;
int head_load_time_;
bool dma_mode_;
// A count of head unload timers currently running.
int head_timers_running_;
// Transient storage and counters used while reading the disk.
uint8_t header_[6];
int distance_into_section_;
int index_hole_limit_;
// Keeps track of the drive and head in use during commands.
int active_drive_;
int active_head_;
// Internal registers.
uint8_t cylinder_, head_, sector_, size_;
bool seek_is_satisfied(int drive);
};
}

10
Storage/Disk/Formats/CPCDSK.cpp
View File

@ -123,14 +123,14 @@ std::shared_ptr<Track> CPCDSK::get_uncached_track_at_position(unsigned int head,
new_sector.data.resize(data_size);
fread(new_sector.data.data(), sizeof(uint8_t), data_size, file_);
if(sector_info.status1 & 0x08) {
// The CRC failed in the ID field.
new_sector.has_header_crc_error = true;
}
if(sector_info.status2 & 0x20) {
// The CRC failed in the data field.
new_sector.has_data_crc_error = true;
} else {
if(sector_info.status1 & 0x20) {
// The CRC failed in the ID field.
new_sector.has_header_crc_error = true;
}
}
if(sector_info.status2 & 0x40) {