From adfdfa205f666538dbc18fe15102c25c738e4cc6 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 12 Feb 2021 18:42:12 -0500
Subject: [PATCH] Starts to establish the means by which I'll implement ADB
devices.
---
Machines/Apple/ADB/Bus.cpp | 48 +++++++++++--------
Machines/Apple/ADB/Bus.hpp | 29 ++++++++---
Machines/Apple/ADB/ReactiveDevice.cpp | 21 ++++++++
Machines/Apple/ADB/ReactiveDevice.hpp | 35 ++++++++++++++
.../Clock Signal.xcodeproj/project.pbxproj | 8 ++++
5 files changed, 115 insertions(+), 26 deletions(-)
create mode 100644 Machines/Apple/ADB/ReactiveDevice.cpp
create mode 100644 Machines/Apple/ADB/ReactiveDevice.hpp
diff --git a/Machines/Apple/ADB/Bus.cpp b/Machines/Apple/ADB/Bus.cpp
index fc424013a..82cfadc91 100644
--- a/Machines/Apple/ADB/Bus.cpp
+++ b/Machines/Apple/ADB/Bus.cpp
@@ -14,17 +14,12 @@ Bus::Bus(HalfCycles clock_speed) : half_cycles_to_microseconds_(1'000'000.0 / cl
void Bus::run_for(HalfCycles duration) {
time_in_state_ += duration;
+ time_since_get_state_ += duration;
}
-size_t Bus::add_device() {
- const size_t id = next_device_id_;
- ++next_device_id_;
- return id;
-}
-
-void Bus::set_device_output(size_t device, bool output) {
+void Bus::set_device_output(size_t device_id, bool output) {
// Modify the all-devices bus state.
- bus_state_[device] = output;
+ bus_state_[device_id] = output;
// React to signal edges only.
const bool data_level = get_state();
@@ -45,12 +40,12 @@ void Bus::set_device_output(size_t device, bool output) {
// 50–72 µs 0
// 300 µs service request
if(low_microseconds > 1040.0) {
- for(auto observer: observers_) {
- observer->adb_bus_did_observe_event(this, Event::Reset);
+ for(auto device: devices_) {
+ device->adb_bus_did_observe_event(Event::Reset);
}
} else if(low_microseconds >= 560.0) {
- for(auto observer: observers_) {
- observer->adb_bus_did_observe_event(this, Event::Attention);
+ for(auto device: devices_) {
+ device->adb_bus_did_observe_event(Event::Attention);
}
shift_register_ = 1;
} else if(low_microseconds < 50.0) {
@@ -58,12 +53,12 @@ void Bus::set_device_output(size_t device, bool output) {
} else if(low_microseconds < 72.0) {
shift(0);
} else if(low_microseconds >= 291.0 && low_microseconds <= 309.0) {
- for(auto observer: observers_) {
- observer->adb_bus_did_observe_event(this, Event::ServiceRequest);
+ for(auto device: devices_) {
+ device->adb_bus_did_observe_event(Event::ServiceRequest);
}
} else {
- for(auto observer: observers_) {
- observer->adb_bus_did_observe_event(this, Event::Unrecognised);
+ for(auto device: devices_) {
+ device->adb_bus_did_observe_event(Event::Unrecognised);
}
}
}
@@ -77,17 +72,30 @@ void Bus::shift(unsigned int value) {
// Trigger a byte whenever a start bit hits bit 9.
if(shift_register_ & 0x200) {
- for(auto observer: observers_) {
- observer->adb_bus_did_observe_event(this, Event::Byte, uint8_t(shift_register_ >> 1));
+ for(auto device: devices_) {
+ device->adb_bus_did_observe_event(Event::Byte, uint8_t(shift_register_ >> 1));
}
shift_register_ = 0;
}
}
bool Bus::get_state() const {
+ const auto microseconds = time_since_get_state_.as<double>() * half_cycles_to_microseconds_;
+ time_since_get_state_ = HalfCycles(0);
+
+ for(auto device: devices_) {
+ device->advance_state(microseconds);
+ }
return bus_state_.all();
}
-void Bus::add_observer(Observer *observer) {
- observers_.push_back(observer);
+size_t Bus::add_device() {
+ const size_t id = next_device_id_;
+ ++next_device_id_;
+ return id;
+}
+
+size_t Bus::add_device(Device *device) {
+ devices_.push_back(device);
+ return add_device();
}
diff --git a/Machines/Apple/ADB/Bus.hpp b/Machines/Apple/ADB/Bus.hpp
index 1b7e1b102..48d7c56cf 100644
--- a/Machines/Apple/ADB/Bus.hpp
+++ b/Machines/Apple/ADB/Bus.hpp
@@ -58,6 +58,15 @@ inline Command decode_command(uint8_t code) {
The ADB bus models the data line of the ADB bus; it allows multiple devices to
post their current data level, or read the current level, and also offers a tokenised
version of all activity on the bus.
+
+ In implementation terms, two types of device are envisaged:
+
+ * proactive devices, which use @c add_device() and then merely @c set_device_output
+ and @c get_state() as required, according to their own tracking of time; and
+
+ * reactive devices, which use @c add_device(Device*) and then merely react to
+ @c adb_bus_did_observe_event and @c advance_state in order to
+ update @c set_device_output.
*/
class Bus {
public:
@@ -77,7 +86,7 @@ class Bus {
/*!
Sets the current data line output for @c device.
*/
- void set_device_output(size_t device, bool output);
+ void set_device_output(size_t device_id, bool output);
/*!
@returns The current state of the ADB data line.
@@ -93,20 +102,28 @@ class Bus {
Unrecognised
};
- struct Observer {
+ struct Device {
/// Reports to an observer that @c event was observed in the activity
/// observed on this bus. If this was a byte event, that byte's value is given as @c value.
- virtual void adb_bus_did_observe_event(Bus *, Event event, uint8_t value = 0xff);
+ virtual void adb_bus_did_observe_event(Event event, uint8_t value = 0xff) = 0;
+
+ /// Requests that the device update itself @c microseconds and, if necessary, post a
+ /// new value ot @c set_device_output. This will be called only when the bus needs
+ /// to reevaluate its current level. It cannot reliably be used to track the timing between
+ /// observed events.
+ virtual void advance_state(double microseconds) = 0;
};
/*!
- Adds an observer.
+ Adds a device.
*/
- void add_observer(Observer *);
+ size_t add_device(Device *);
private:
HalfCycles time_in_state_;
+ mutable HalfCycles time_since_get_state_;
+
double half_cycles_to_microseconds_ = 1.0;
- std::vector<Observer *> observers_;
+ std::vector<Device *> devices_;
unsigned int shift_register_ = 0;
bool data_level_ = true;
diff --git a/Machines/Apple/ADB/ReactiveDevice.cpp b/Machines/Apple/ADB/ReactiveDevice.cpp
new file mode 100644
index 000000000..67396abf2
--- /dev/null
+++ b/Machines/Apple/ADB/ReactiveDevice.cpp
@@ -0,0 +1,21 @@
+//
+// ReactiveDevice.cpp
+// Clock Signal
+//
+// Created by Thomas Harte on 12/02/2021.
+// Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#include "ReactiveDevice.hpp"
+
+using namespace Apple::ADB;
+
+ReactiveDevice::ReactiveDevice(Apple::ADB::Bus &bus) : device_id_(bus.add_device(this)) {}
+
+void ReactiveDevice::post_response(const std::vector<uint8_t> &&response) {
+ response_ = std::move(response);
+}
+
+void ReactiveDevice::advance_state(double microseconds) {
+ (void)microseconds;
+}
diff --git a/Machines/Apple/ADB/ReactiveDevice.hpp b/Machines/Apple/ADB/ReactiveDevice.hpp
new file mode 100644
index 000000000..e9c92494d
--- /dev/null
+++ b/Machines/Apple/ADB/ReactiveDevice.hpp
@@ -0,0 +1,35 @@
+//
+// ReactiveDevice.hpp
+// Clock Signal
+//
+// Created by Thomas Harte on 12/02/2021.
+// Copyright © 2021 Thomas Harte. All rights reserved.
+//
+
+#ifndef ReactiveDevice_hpp
+#define ReactiveDevice_hpp
+
+#include "Bus.hpp"
+
+#include <cstddef>
+#include <vector>
+
+namespace Apple {
+namespace ADB {
+
+class ReactiveDevice: public Bus::Device {
+ protected:
+ ReactiveDevice(Bus &bus);
+
+ void post_response(const std::vector<uint8_t> &&response);
+ void advance_state(double microseconds) override;
+
+ private:
+ const size_t device_id_;
+ std::vector<uint8_t> response_;
+};
+
+}
+}
+
+#endif /* ReactiveDevice_hpp */
diff --git a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
index 428312bd6..1dafeca2a 100644
--- a/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
+++ b/OSBindings/Mac/Clock Signal.xcodeproj/project.pbxproj
@@ -172,6 +172,8 @@
4B2BFDB21DAEF5FF001A68B8 /* Video.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2BFDB01DAEF5FF001A68B8 /* Video.cpp */; };
4B2C45421E3C3896002A2389 /* cartridge.png in Resources */ = {isa = PBXBuildFile; fileRef = 4B2C45411E3C3896002A2389 /* cartridge.png */; };
4B2E2D9D1C3A070400138695 /* Electron.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2E2D9B1C3A070400138695 /* Electron.cpp */; };
+ 4B2E86B725D7490E0024F1E9 /* ReactiveDevice.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2E86B525D7490E0024F1E9 /* ReactiveDevice.cpp */; };
+ 4B2E86B825D7490E0024F1E9 /* ReactiveDevice.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B2E86B525D7490E0024F1E9 /* ReactiveDevice.cpp */; };
4B302184208A550100773308 /* DiskII.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B302183208A550100773308 /* DiskII.cpp */; };
4B302185208A550100773308 /* DiskII.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B302183208A550100773308 /* DiskII.cpp */; };
4B30512D1D989E2200B4FED8 /* Drive.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 4B30512B1D989E2200B4FED8 /* Drive.cpp */; };
@@ -1116,6 +1118,8 @@
4B2C455C1EC9442600FC74DD /* RegisterSizes.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = RegisterSizes.hpp; sourceTree = "<group>"; };
4B2E2D9B1C3A070400138695 /* Electron.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; name = Electron.cpp; path = Electron/Electron.cpp; sourceTree = "<group>"; };
4B2E2D9C1C3A070400138695 /* Electron.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; name = Electron.hpp; path = Electron/Electron.hpp; sourceTree = "<group>"; };
+ 4B2E86B525D7490E0024F1E9 /* ReactiveDevice.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = ReactiveDevice.cpp; sourceTree = "<group>"; };
+ 4B2E86B625D7490E0024F1E9 /* ReactiveDevice.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = ReactiveDevice.hpp; sourceTree = "<group>"; };
4B302182208A550100773308 /* DiskII.hpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.h; path = DiskII.hpp; sourceTree = "<group>"; };
4B302183208A550100773308 /* DiskII.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = DiskII.cpp; sourceTree = "<group>"; };
4B30512B1D989E2200B4FED8 /* Drive.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = Drive.cpp; sourceTree = "<group>"; };
@@ -4189,6 +4193,8 @@
children = (
4BCE1DEF25D4C3FA00AE7A2B /* Bus.cpp */,
4BCE1DF025D4C3FA00AE7A2B /* Bus.hpp */,
+ 4B2E86B525D7490E0024F1E9 /* ReactiveDevice.cpp */,
+ 4B2E86B625D7490E0024F1E9 /* ReactiveDevice.hpp */,
);
path = ADB;
sourceTree = "<group>";
@@ -5108,6 +5114,7 @@
4B055A991FAE85CB0060FFFF /* DiskController.cpp in Sources */,
4B25B5F925BD083C00362C84 /* DiskIIDrive.cpp in Sources */,
4B055ACC1FAE9B030060FFFF /* Electron.cpp in Sources */,
+ 4B2E86B825D7490E0024F1E9 /* ReactiveDevice.cpp in Sources */,
4B74CF822312FA9C00500CE8 /* HFV.cpp in Sources */,
4B8318B022D3E531006DB630 /* AppleII.cpp in Sources */,
4B1B58F7246CC4E8009C171E /* State.cpp in Sources */,
@@ -5284,6 +5291,7 @@
4BE21219253FCE9C00435408 /* AppleIIgs.cpp in Sources */,
4BCE0060227D39AB000CA200 /* Video.cpp in Sources */,
4B0ACC2E23775819008902D0 /* TIA.cpp in Sources */,
+ 4B2E86B725D7490E0024F1E9 /* ReactiveDevice.cpp in Sources */,
4B74CF85231370BC00500CE8 /* MacintoshVolume.cpp in Sources */,
4B4518A51F75FD1C00926311 /* SSD.cpp in Sources */,
4B55CE5F1C3B7D960093A61B /* MachineDocument.swift in Sources */,