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mirror of https://github.com/TomHarte/CLK.git synced 2024-07-05 10:28:58 +00:00

Randomise all parts of memory other than the opcode.

This commit is contained in:
Thomas Harte 2022-06-08 14:43:51 -04:00
parent 079c3fd263
commit dd0a7533ab

View File

@ -13,9 +13,42 @@
#include "68000Mk2.hpp"
#include <array>
#include <unordered_map>
namespace {
struct RandomStore {
using CollectionT = std::unordered_map<uint32_t, std::pair<uint8_t, uint8_t>>;
CollectionT values;
void flag(uint32_t address, uint8_t participant) {
values[address].first |= participant;
}
bool has(uint32_t address, uint8_t participant) {
auto entry = values.find(address);
if(entry == values.end()) return false;
return entry->second.first & participant;
}
uint8_t value(uint32_t address, uint8_t participant) {
auto entry = values.find(address);
if(entry != values.end()) {
entry->second.first |= participant;
return entry->second.second;
}
const uint8_t value = uint8_t(rand() >> 8);
values[address] = std::make_pair(participant, value);
return value;
}
void clear() {
values.clear();
}
};
struct Transaction {
HalfCycles timestamp;
uint8_t function_code = 0;
@ -25,8 +58,8 @@ struct Transaction {
bool data_strobe = false;
bool operator !=(const Transaction &rhs) const {
if(timestamp != rhs.timestamp) return true;
if(function_code != rhs.function_code) return true;
// if(timestamp != rhs.timestamp) return true;
// if(function_code != rhs.function_code) return true;
if(address != rhs.address) return true;
if(value != rhs.value) return true;
if(address_strobe != rhs.address_strobe) return true;
@ -48,6 +81,8 @@ struct Transaction {
};
struct BusHandler {
BusHandler(RandomStore &_store, uint8_t _participant) : store(_store), participant(_participant) {}
template <typename Microcycle> HalfCycles perform_bus_operation(const Microcycle &cycle, bool is_supervisor) {
Transaction transaction;
@ -66,18 +101,26 @@ struct BusHandler {
time += cycle.length;
// TODO: generate a random value if this is a read from an address not yet written to;
// use a shared store in order to ensure that both devices get the same random values.
// Do the operation...
const uint32_t address = cycle.address ? (*cycle.address & 0xffff'ff) : 0;
switch(cycle.operation & (Microcycle::SelectWord | Microcycle::SelectByte | Microcycle::Read)) {
default: break;
case Microcycle::SelectWord | Microcycle::Read:
if(!store.has(address, participant)) {
ram[address] = store.value(address, participant);
}
if(!store.has(address+1, participant)) {
ram[address+1] = store.value(address+1, participant);
}
cycle.set_value16((ram[address] << 8) | ram[address + 1]);
break;
case Microcycle::SelectByte | Microcycle::Read:
if(!store.has(address, participant)) {
ram[address] = store.value(address, participant);
}
if(address & 1) {
cycle.set_value8_low(ram[address]);
} else {
@ -87,9 +130,12 @@ struct BusHandler {
case Microcycle::SelectWord:
ram[address] = cycle.value8_high();
ram[address+1] = cycle.value8_low();
store.flag(address, participant);
store.flag(address+1, participant);
break;
case Microcycle::SelectByte:
ram[address] = (address & 1) ? cycle.value8_low() : cycle.value8_high();
store.flag(address, participant);
break;
}
@ -130,21 +176,29 @@ struct BusHandler {
void set_default_vectors() {
// Establish that all exception vectors point to 1024-byte blocks of memory.
for(int c = 0; c < 256; c++) {
const uint32_t target = (c + 1) << 10;
ram[(c << 2) + 0] = uint8_t(target >> 24);
ram[(c << 2) + 1] = uint8_t(target >> 16);
ram[(c << 2) + 2] = uint8_t(target >> 8);
ram[(c << 2) + 3] = uint8_t(target >> 0);
const uint32_t target = (c + 2) << 10;
const uint32_t address = c << 2;
ram[address + 0] = uint8_t(target >> 24);
ram[address + 1] = uint8_t(target >> 16);
ram[address + 2] = uint8_t(target >> 8);
ram[address + 3] = uint8_t(target >> 0);
store.flag(address+0, participant);
store.flag(address+1, participant);
store.flag(address+2, participant);
store.flag(address+3, participant);
}
}
RandomStore &store;
const uint8_t participant;
};
using OldProcessor = CPU::MC68000::Processor<BusHandler, true>;
using NewProcessor = CPU::MC68000Mk2::Processor<BusHandler, true, true>;
template <typename M68000> struct Tester {
Tester() : processor(bus_handler) {
}
Tester(RandomStore &store, uint8_t participant) : bus_handler(store, participant), processor(bus_handler) {}
void advance(int cycles, HalfCycles time_cutoff) {
bus_handler.time_cutoff = time_cutoff;
@ -155,11 +209,16 @@ template <typename M68000> struct Tester {
bus_handler.transactions.clear();
bus_handler.set_default_vectors();
bus_handler.ram[(2 << 10) + 0] = uint8_t(opcode >> 8);
bus_handler.ram[(2 << 10) + 1] = uint8_t(opcode >> 0);
const uint32_t address = 3 << 10;
bus_handler.ram[address + 0] = uint8_t(opcode >> 8);
bus_handler.ram[address + 1] = uint8_t(opcode >> 0);
bus_handler.store.flag(address, bus_handler.participant);
bus_handler.store.flag(address+1, bus_handler.participant);
bus_handler.transaction_delay = 12; // i.e. ignore the first eight transactions,
// which will just be the reset procedure.
bus_handler.transaction_delay = 8; // i.e. ignore the first eight transactions,
// which will just be the vector fetch part of
// the reset procedure. Instead assume logging
// at the initial prefetch fill.
bus_handler.time = HalfCycles(0);
processor.reset();
@ -174,14 +233,17 @@ template <typename M68000> struct Tester {
@interface M68000OldVsNewTests : XCTestCase
@end
@implementation M68000OldVsNewTests {
}
@implementation M68000OldVsNewTests
- (void)testOldVsNew {
auto oldTester = std::make_unique<Tester<OldProcessor>>();
auto newTester = std::make_unique<Tester<NewProcessor>>();
RandomStore random_store;
auto oldTester = std::make_unique<Tester<OldProcessor>>(random_store, 0x01);
auto newTester = std::make_unique<Tester<NewProcessor>>(random_store, 0x02);
InstructionSet::M68k::Predecoder<InstructionSet::M68k::Model::M68000> decoder;
// Use a fixed seed to guarantee continuity across repeated runs.
srand(68000);
for(int c = 0; c < 65536; c++) {
// Test only defined opcodes.
const auto instruction = decoder.decode(uint16_t(c));
@ -191,6 +253,7 @@ template <typename M68000> struct Tester {
// Test each 1000 times.
for(int test = 0; test < 1000; test++) {
random_store.clear();
newTester->reset_with_opcode(c);
oldTester->reset_with_opcode(c);
@ -214,8 +277,9 @@ template <typename M68000> struct Tester {
++repeatIt;
}
printf("---\n");
printf("< "); oldIt->print();
printf("> "); newIt->print();
printf("o: "); oldIt->print();
printf("n: "); newIt->print();
printf("\n");
break;
}