From af70c8847dbad8eaab3ab722e7f6f41b2e5fb6d4 Mon Sep 17 00:00:00 2001 From: Thomas Harte Date: Fri, 24 Nov 2023 18:24:58 -0500 Subject: [PATCH] Factor out the stuff of accumulating and dissecting commands. --- Components/8272/CommandDecoder.hpp | 221 ++++++++++++++++++ Components/8272/i8272.cpp | 207 +++++++--------- Components/8272/i8272.hpp | 4 +- .../Clock Signal.xcodeproj/project.pbxproj | 2 + 4 files changed, 308 insertions(+), 126 deletions(-) create mode 100644 Components/8272/CommandDecoder.hpp diff --git a/Components/8272/CommandDecoder.hpp b/Components/8272/CommandDecoder.hpp new file mode 100644 index 000000000..7bf274ac3 --- /dev/null +++ b/Components/8272/CommandDecoder.hpp @@ -0,0 +1,221 @@ +// +// CommandDecoder.hpp +// Clock Signal +// +// Created by Thomas Harte on 24/11/2023. +// Copyright © 2023 Thomas Harte. All rights reserved. +// + +#ifndef CommandDecoder_hpp +#define CommandDecoder_hpp + +#include +#include +#include + +namespace Intel::i8272 { + +class CommandDecoder { + public: + enum class Command { + ReadData = 0x06, + ReadDeletedData = 0x0c, + + WriteData = 0x05, + WriteDeletedData = 0x09, + + ReadTrack = 0x02, + ReadID = 0x0a, + FormatTrack = 0x0d, + + ScanLow = 0x11, + ScanLowOrEqual = 0x19, + ScanHighOrEqual = 0x1d, + + Recalibrate = 0x07, + Seek = 0x0f, + + SenseInterruptStatus = 0x08, + Specify = 0x03, + SenseDriveStatus = 0x04, + + Invalid = 0x00, + }; + + /// Add a byte to the current command. + void push_back(uint8_t byte) { + command_.push_back(byte); + } + + /// Reset decoding. + void clear() { + command_.clear(); + } + + /// @returns @c true if an entire command has been received; @c false if further bytes are needed. + bool has_command() const { + if(!command_.size()) { + return false; + } + + static constexpr std::size_t required_lengths[32] = { + 0, 0, 9, 3, 2, 9, 9, 2, + 1, 9, 2, 0, 9, 6, 0, 3, + 0, 9, 0, 0, 0, 0, 0, 0, + 0, 9, 0, 0, 0, 9, 0, 0, + }; + + return command_.size() >= required_lengths[command_[0] & 0x1f]; + } + + /// @returns The command requested. Valid only if @c has_command() is @c true. + Command command() const { + const auto command = Command(command_[0] & 0x1f); + + switch(command) { + case Command::ReadData: case Command::ReadDeletedData: + case Command::WriteData: case Command::WriteDeletedData: + case Command::ReadTrack: case Command::ReadID: + case Command::FormatTrack: + case Command::ScanLow: case Command::ScanLowOrEqual: + case Command::ScanHighOrEqual: + case Command::Recalibrate: case Command::Seek: + case Command::SenseInterruptStatus: + case Command::Specify: case Command::SenseDriveStatus: + return command; + + default: return Command::Invalid; + } + } + + // + // Commands that specify geometry; i.e. + // + // * ReadData; + // * ReadDeletedData; + // * WriteData; + // * WriteDeletedData; + // * ReadTrack; + // * ScanEqual; + // * ScanLowOrEqual; + // * ScanHighOrEqual. + // + + /// @returns @c true if this command specifies geometry, in which case geomtry() is well-defined. + /// @c false otherwise. + bool has_geometry() const { return command_.size() == 9; } + struct Geometry { + uint8_t cylinder, head, sector, size, end_of_track; + }; + Geometry geometry() const { + Geometry result; + result.cylinder = command_[2]; + result.head = command_[3]; + result.sector = command_[4]; + result.size = command_[5]; + result.end_of_track = command_[6]; + return result; + } + + // + // Commands that imply data access; i.e. + // + // * ReadData; + // * ReadDeletedData; + // * WriteData; + // * WriteDeletedData; + // * ReadTrack; + // * ReadID; + // * FormatTrack; + // * ScanLow; + // * ScanLowOrEqual; + // * ScanHighOrEqual. + // + + /// @returns @c true if this command involves reading or writing data, in which case target() will be valid. + /// @c false otherwise. + bool is_access_command() const { + switch(command()) { + case Command::ReadData: case Command::ReadDeletedData: + case Command::WriteData: case Command::WriteDeletedData: + case Command::ReadTrack: case Command::ReadID: + case Command::FormatTrack: + case Command::ScanLow: case Command::ScanLowOrEqual: + case Command::ScanHighOrEqual: + return true; + + default: + return false; + } + } + struct AccessTarget { + uint8_t drive, head; + bool mfm, skip_deleted; + }; + AccessTarget target() const { + AccessTarget result; + result.drive = command_[1] & 0x03; + result.head = (command_[1] >> 2) & 0x01; + result.mfm = command_[0] & 0x40; + result.skip_deleted = command_[0] & 0x20; + return result; + } + uint8_t drive_head() const { + return command_[1]&7; + } + + // + // Command::FormatTrack + // + + struct FormatSpecs { + uint8_t bytes_per_sector; + uint8_t sectors_per_track; + uint8_t gap3_length; + uint8_t filler; + }; + FormatSpecs format_specs() const { + FormatSpecs result; + result.bytes_per_sector = command_[2]; + result.sectors_per_track = command_[3]; + result.gap3_length = command_[4]; + result.filler = command_[5]; + return result; + } + + // + // Command::Seek + // + + /// @returns The desired target track. + uint8_t seek_target() const { + return command_[2]; + } + + // + // Command::Specify + // + + struct SpecifySpecs { + // The below are all in milliseconds. + uint8_t step_rate_time; + uint8_t head_unload_time; + uint8_t head_load_time; + bool use_dma; + }; + SpecifySpecs specify_specs() const { + SpecifySpecs result; + result.step_rate_time = 16 - (command_[1] >> 4); // i.e. 1 to 16ms + result.head_unload_time = uint8_t((command_[1] & 0x0f) << 4); // i.e. 16 to 240ms + result.head_load_time = command_[2] & ~1; // i.e. 2 to 254 ms in increments of 2ms + result.use_dma = !(command_[2] & 1); + return result; + } + + private: + std::vector command_; +}; + +} + +#endif /* CommandDecoder_hpp */ diff --git a/Components/8272/i8272.cpp b/Components/8272/i8272.cpp index 95e735984..aff663127 100644 --- a/Components/8272/i8272.cpp +++ b/Components/8272/i8272.cpp @@ -53,29 +53,6 @@ using namespace Intel::i8272; #define SetBadCylinder() (status_[2] |= 0x02) #define SetMissingDataAddressMark() (status_[2] |= 0x01) -namespace { - const uint8_t CommandReadData = 0x06; - const uint8_t CommandReadDeletedData = 0x0c; - - const uint8_t CommandWriteData = 0x05; - const uint8_t CommandWriteDeletedData = 0x09; - - const uint8_t CommandReadTrack = 0x02; - const uint8_t CommandReadID = 0x0a; - const uint8_t CommandFormatTrack = 0x0d; - - const uint8_t CommandScanLow = 0x11; - const uint8_t CommandScanLowOrEqual = 0x19; - const uint8_t CommandScanHighOrEqual = 0x1d; - - const uint8_t CommandRecalibrate = 0x07; - const uint8_t CommandSeek = 0x0f; - - const uint8_t CommandSenseInterruptStatus = 0x08; - const uint8_t CommandSpecify = 0x03; - const uint8_t CommandSenseDriveStatus = 0x04; -} - i8272::i8272(BusHandler &bus_handler, Cycles clock_rate) : Storage::Disk::MFMController(clock_rate), bus_handler_(bus_handler) { @@ -233,12 +210,12 @@ uint8_t i8272::read(int address) { if(distance_into_section_ < 6) goto CONCAT(read_header, __LINE__); \ #define SET_DRIVE_HEAD_MFM() \ - active_drive_ = command_[1]&3; \ - active_head_ = (command_[1] >> 2)&1; \ - status_[0] = (command_[1]&7); \ + active_drive_ = command_.target().drive; \ + active_head_ = command_.target().head; \ + status_[0] = command_.drive_head(); \ select_drive(active_drive_); \ get_drive().set_head(active_head_); \ - set_is_double_density(command_[0] & 0x40); + set_is_double_density(command_.target().mfm); #define WAIT_FOR_BYTES(n) \ distance_into_section_ = 0; \ @@ -296,42 +273,20 @@ void i8272::posit_event(int event_type) { WAIT_FOR_EVENT(Event8272::CommandByte) SetBusy(); - static constexpr std::size_t required_lengths[32] = { - 0, 0, 9, 3, 2, 9, 9, 2, - 1, 9, 2, 0, 9, 6, 0, 3, - 0, 9, 0, 0, 0, 0, 0, 0, - 0, 9, 0, 0, 0, 9, 0, 0, - }; - - if(command_.size() < required_lengths[command_[0] & 0x1f]) goto wait_for_complete_command_sequence; - if(command_.size() == 9) { - cylinder_ = command_[2]; - head_ = command_[3]; - sector_ = command_[4]; - size_ = command_[5]; + if(!command_.has_command()) { + goto wait_for_complete_command_sequence; + } + if(command_.has_geometry() == 9) { + cylinder_ = command_.geometry().cylinder; + head_ = command_.geometry().head; + sector_ = command_.geometry().sector; + size_ = command_.geometry().size; } ResetDataRequest(); status_[0] = status_[1] = status_[2] = 0; // If this is not clearly a command that's safe to carry out in parallel to a seek, end all seeks. - switch(command_[0] & 0x1f) { - case CommandReadData: - case CommandReadDeletedData: - case CommandWriteData: - case CommandWriteDeletedData: - case CommandReadTrack: - case CommandReadID: - case CommandFormatTrack: - case CommandScanLow: - case CommandScanLowOrEqual: - case CommandScanHighOrEqual: - is_access_command_ = true; - break; - - default: - is_access_command_ = false; - break; - } + is_access_command_ = command_.is_access_command(); if(is_access_command_) { for(int c = 0; c < 4; c++) { @@ -353,29 +308,30 @@ void i8272::posit_event(int event_type) { } // Jump to the proper place. - switch(command_[0] & 0x1f) { - case CommandReadData: - case CommandReadDeletedData: + using Command = CommandDecoder::Command; + switch(command_.command()) { + case Command::ReadData: + case Command::ReadDeletedData: goto read_data; - case CommandWriteData: - case CommandWriteDeletedData: + case Command::WriteData: + case Command::WriteDeletedData: goto write_data; - case CommandReadTrack: goto read_track; - case CommandReadID: goto read_id; - case CommandFormatTrack: goto format_track; + case Command::ReadTrack: goto read_track; + case Command::ReadID: goto read_id; + case Command::FormatTrack: goto format_track; - case CommandScanLow: goto scan_low; - case CommandScanLowOrEqual: goto scan_low_or_equal; - case CommandScanHighOrEqual: goto scan_high_or_equal; + case Command::ScanLow: goto scan_low; + case Command::ScanLowOrEqual: goto scan_low_or_equal; + case Command::ScanHighOrEqual: goto scan_high_or_equal; - case CommandRecalibrate: goto recalibrate; - case CommandSeek: goto seek; + case Command::Recalibrate: goto recalibrate; + case Command::Seek: goto seek; - case CommandSenseInterruptStatus: goto sense_interrupt_status; - case CommandSpecify: goto specify; - case CommandSenseDriveStatus: goto sense_drive_status; + case Command::SenseInterruptStatus: goto sense_interrupt_status; + case Command::Specify: goto specify; + case Command::SenseDriveStatus: goto sense_drive_status; default: goto invalid; } @@ -415,26 +371,27 @@ void i8272::posit_event(int event_type) { // Branch to whatever is supposed to happen next // LOG("Proceeding"); - switch(command_[0] & 0x1f) { - case CommandReadData: - case CommandReadDeletedData: + switch(command_.command()) { + default: + case Command::ReadData: + case Command::ReadDeletedData: goto read_data_found_header; - case CommandWriteData: // write data - case CommandWriteDeletedData: // write deleted data + case Command::WriteData: // write data + case Command::WriteDeletedData: // write deleted data goto write_data_found_header; } // Performs the read data or read deleted data command. read_data: - LOG(PADHEX(2) << "Read [deleted] data [" - << int(command_[2]) << " " - << int(command_[3]) << " " - << int(command_[4]) << " " - << int(command_[5]) << " ... " - << int(command_[6]) << " " - << int(command_[8]) << "]"); +// LOG(PADHEX(2) << "Read [deleted] data [" +// << int(command_[2]) << " " +// << int(command_[3]) << " " +// << int(command_[4]) << " " +// << int(command_[5]) << " ... " +// << int(command_[6]) << " " +// << int(command_[8]) << "]"); read_next_data: goto read_write_find_header; @@ -450,8 +407,8 @@ void i8272::posit_event(int event_type) { SetMissingDataAddressMark(); goto abort; // TODO: or read_next_data? } else { - if((get_latest_token().type == Token::Data) != ((command_[0] & 0x1f) == CommandReadData)) { - if(!(command_[0]&0x20)) { + if((get_latest_token().type == Token::Data) != (command_.command() == Command::ReadData)) { + if(!command_.target().skip_deleted) { // SK is not set; set the error flag but read this sector before finishing. SetControlMark(); } else { @@ -509,7 +466,7 @@ void i8272::posit_event(int event_type) { // 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] && !ControlMark()) { + if(sector_ != command_.geometry().end_of_track && !ControlMark()) { sector_++; goto read_next_data; } @@ -518,13 +475,13 @@ void i8272::posit_event(int event_type) { goto post_st012chrn; write_data: - LOG(PADHEX(2) << "Write [deleted] data [" - << int(command_[2]) << " " - << int(command_[3]) << " " - << int(command_[4]) << " " - << int(command_[5]) << " ... " - << int(command_[6]) << " " - << int(command_[8]) << "]"); +// LOG(PADHEX(2) << "Write [deleted] data [" +// << int(command_[2]) << " " +// << int(command_[3]) << " " +// << int(command_[4]) << " " +// << int(command_[5]) << " ... " +// << int(command_[6]) << " " +// << int(command_[8]) << "]"); if(get_drive().get_is_read_only()) { SetNotWriteable(); @@ -538,7 +495,7 @@ void i8272::posit_event(int event_type) { WAIT_FOR_BYTES(get_is_double_density() ? 22 : 11); begin_writing(true); - write_id_data_joiner((command_[0] & 0x1f) == CommandWriteDeletedData, true); + write_id_data_joiner(command_.command() == Command::WriteDeletedData, true); SetDataDirectionFromProcessor(); SetDataRequest(); @@ -565,7 +522,7 @@ void i8272::posit_event(int event_type) { WAIT_FOR_EVENT(Event::DataWritten); end_writing(); - if(sector_ != command_[6]) { + if(sector_ != command_.geometry().end_of_track) { sector_++; goto write_next_data; } @@ -575,7 +532,7 @@ void i8272::posit_event(int event_type) { // Performs the read ID command. read_id: // Establishes the drive and head being addressed, and whether in double density mode. - LOG(PADHEX(2) << "Read ID [" << int(command_[0]) << " " << int(command_[1]) << "]"); +// LOG(PADHEX(2) << "Read ID [" << int(command_[0]) << " " << int(command_[1]) << "]"); // 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. @@ -597,11 +554,11 @@ void i8272::posit_event(int event_type) { // Performs read track. read_track: - LOG(PADHEX(2) << "Read track [" - << int(command_[2]) << " " - << int(command_[3]) << " " - << int(command_[4]) << " " - << int(command_[5]) << "]"); +// LOG(PADHEX(2) << "Read track [" +// << int(command_[2]) << " " +// << int(command_[3]) << " " +// << int(command_[4]) << " " +// << int(command_[5]) << "]"); // Wait for the index hole. WAIT_FOR_EVENT(Event::IndexHole); @@ -636,7 +593,7 @@ void i8272::posit_event(int event_type) { if(distance_into_section_ < (128 << header_[2])) goto read_track_get_byte; sector_++; - if(sector_ < command_[6]) goto read_track_next_sector; + if(sector_ < command_.geometry().end_of_track) goto read_track_next_sector; goto post_st012chrn; @@ -696,15 +653,15 @@ void i8272::posit_event(int event_type) { // Write the sector body. write_id_data_joiner(false, false); - write_n_bytes(128 << command_[2], command_[5]); + write_n_bytes(128 << command_.format_specs().bytes_per_sector, command_.format_specs().filler); write_crc(); // Write the prescribed gap. - write_n_bytes(command_[4], get_is_double_density() ? 0x4e : 0xff); + write_n_bytes(command_.format_specs().gap3_length, get_is_double_density() ? 0x4e : 0xff); // Consider repeating. sector_++; - if(sector_ < command_[3] && !index_hole_count_) + if(sector_ < command_.format_specs().sectors_per_track && !index_hole_count_) goto format_track_write_sector; // Otherwise, pad out to the index hole. @@ -739,7 +696,7 @@ void i8272::posit_event(int event_type) { recalibrate: seek: { - int drive = command_[1]&3; + const int drive = command_.target().drive; select_drive(drive); // Increment the seeking count if this drive wasn't already seeking. @@ -755,14 +712,14 @@ void i8272::posit_event(int event_type) { drives_[drive].step_rate_counter = 8000 * step_rate_time_; drives_[drive].steps_taken = 0; drives_[drive].seek_failed = false; - main_status_ |= 1 << (command_[1]&3); + main_status_ |= 1 << command_.target().drive; // If this is a seek, set the processor-supplied target location; otherwise it is a recalibrate, // which means resetting the current state now but aiming to hit '-1' (which the stepping code // up in run_for understands to mean 'keep going until track 0 is active'). - if(command_.size() > 2) { - drives_[drive].target_head_position = command_[2]; - LOG(PADHEX(2) << "Seek to " << int(command_[2])); + if(command_.command() != Command::Recalibrate) { + drives_[drive].target_head_position = command_.seek_target(); + LOG(PADHEX(2) << "Seek to " << int(command_.seek_target())); } else { drives_[drive].target_head_position = -1; drives_[drive].head_position = 0; @@ -808,24 +765,24 @@ void i8272::posit_event(int event_type) { specify: // Just store the values, and terminate the command. LOG("Specify"); - step_rate_time_ = 16 - (command_[1] >> 4); // i.e. 1 to 16ms - head_unload_time_ = (command_[1] & 0x0f) << 4; // i.e. 16 to 240ms - head_load_time_ = command_[2] & ~1; // i.e. 2 to 254 ms in increments of 2ms + step_rate_time_ = command_.specify_specs().step_rate_time; + head_unload_time_ = command_.specify_specs().head_unload_time; + head_load_time_ = command_.specify_specs().head_load_time; if(!head_unload_time_) head_unload_time_ = 16; if(!head_load_time_) head_load_time_ = 2; - dma_mode_ = !(command_[2] & 1); + dma_mode_ = command_.specify_specs().use_dma; goto wait_for_command; sense_drive_status: LOG("Sense drive status"); { - int drive = command_[1] & 3; + int drive = command_.target().drive; select_drive(drive); result_stack_= { uint8_t( - (command_[1] & 7) | // drive and head number - 0x08 | // single sided + (command_.drive_head()) | // drive and head number + 0x08 | // single sided (get_drive().get_is_track_zero() ? 0x10 : 0x00) | (get_drive().get_is_ready() ? 0x20 : 0x00) | (get_drive().get_is_read_only() ? 0x40 : 0x00) @@ -857,11 +814,11 @@ void i8272::posit_event(int event_type) { // Posts whatever is in result_stack_ as a result phase. Be aware that it is a stack, so the // last thing in it will be returned first. post_result: - LOGNBR(PADHEX(2) << "Result to " << int(command_[0] & 0x1f) << ", main " << int(main_status_) << "; "); - for(std::size_t c = 0; c < result_stack_.size(); c++) { - LOGNBR(" " << int(result_stack_[result_stack_.size() - 1 - c])); - } - LOGNBR(std::endl); +// LOGNBR(PADHEX(2) << "Result to " << int(command_[0] & 0x1f) << ", main " << int(main_status_) << "; "); +// for(std::size_t c = 0; c < result_stack_.size(); c++) { +// LOGNBR(" " << int(result_stack_[result_stack_.size() - 1 - c])); +// } +// LOGNBR(std::endl); // Set ready to send data to the processor, no longer in non-DMA execution phase. is_executing_ = false; diff --git a/Components/8272/i8272.hpp b/Components/8272/i8272.hpp index 0c502e3c8..98bd3c960 100644 --- a/Components/8272/i8272.hpp +++ b/Components/8272/i8272.hpp @@ -9,6 +9,8 @@ #ifndef i8272_hpp #define i8272_hpp +#include "CommandDecoder.hpp" + #include "../../Storage/Disk/Controller/MFMDiskController.hpp" #include @@ -54,7 +56,7 @@ class i8272 : public Storage::Disk::MFMController { uint8_t status_[3] = {0, 0, 0}; // A buffer for accumulating the incoming command, and one for accumulating the result. - std::vector command_; + CommandDecoder command_; std::vector result_stack_; uint8_t input_ = 0; bool has_input_ = false; diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj index 80effae5b..cea443d17 100644 --- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj +++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj @@ -1146,6 +1146,7 @@ 4267A9C82B0D4EC2008A59BB /* PIC.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = PIC.hpp; sourceTree = ""; }; 4267A9C92B0D4F17008A59BB /* DMA.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = DMA.hpp; sourceTree = ""; }; 4267A9CA2B111ED2008A59BB /* KeyboardMapper.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = KeyboardMapper.hpp; sourceTree = ""; }; + 4267A9CB2B113958008A59BB /* CommandDecoder.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = CommandDecoder.hpp; sourceTree = ""; }; 4281572E2AA0334300E16AA1 /* Carry.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = Carry.hpp; sourceTree = ""; }; 428168372A16C25C008ECD27 /* LineLayout.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = LineLayout.hpp; sourceTree = ""; }; 428168392A37AFB4008ECD27 /* DispatcherTests.mm */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.objcpp; path = DispatcherTests.mm; sourceTree = ""; }; @@ -4552,6 +4553,7 @@ children = ( 4BBC951C1F368D83008F4C34 /* i8272.cpp */, 4BBC951D1F368D83008F4C34 /* i8272.hpp */, + 4267A9CB2B113958008A59BB /* CommandDecoder.hpp */, ); path = 8272; sourceTree = "";