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CLK/StaticAnalyser/Acorn/AcornAnalyser.cpp

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//
// AcornAnalyser.cpp
// Clock Signal
//
// Created by Thomas Harte on 29/08/2016.
// Copyright © 2016 Thomas Harte. All rights reserved.
//
#include "AcornAnalyser.hpp"
using namespace StaticAnalyser::Acorn;
static std::list<std::shared_ptr<Storage::Cartridge::Cartridge>>
AcornCartridgesFrom(const std::list<std::shared_ptr<Storage::Cartridge::Cartridge>> &cartridges)
{
std::list<std::shared_ptr<Storage::Cartridge::Cartridge>> acorn_cartridges;
for(std::shared_ptr<Storage::Cartridge::Cartridge> cartridge : cartridges)
{
const std::list<Storage::Cartridge::Cartridge::Segment> &segments = cartridge->get_segments();
// only one mapped item is allowed
if(segments.size() != 1) continue;
// which must be 16 kb in size
Storage::Cartridge::Cartridge::Segment segment = segments.front();
if(segment.data.size() != 0x4000) continue;
// is a copyright string present?
uint8_t copyright_offset = segment.data[7];
if(
segment.data[copyright_offset] != 0x00 ||
segment.data[copyright_offset+1] != 0x28 ||
segment.data[copyright_offset+2] != 0x43 ||
segment.data[copyright_offset+3] != 0x29
) continue;
// is the language entry point valid?
if(!(
(segment.data[0] == 0x00 && segment.data[1] == 0x00 && segment.data[2] == 0x00) ||
(segment.data[0] != 0x00 && segment.data[2] >= 0x80 && segment.data[2] < 0xc0)
)) continue;
// is the service entry point valid?
if(!(segment.data[5] >= 0x80 && segment.data[5] < 0xc0)) continue;
// probability of a random binary blob that isn't an Acorn ROM proceeding to here:
// 1/(2^32) *
// ( ((2^24)-1)/(2^24)*(1/4) + 1/(2^24) ) *
// 1/4
// = something very improbable — around 1/16th of 1 in 2^32, but not exactly.
acorn_cartridges.push_back(cartridge);
}
return acorn_cartridges;
}
void StaticAnalyser::Acorn::AddTargets(
const std::list<std::shared_ptr<Storage::Disk::Disk>> &disks,
const std::list<std::shared_ptr<Storage::Tape::Tape>> &tapes,
const std::list<std::shared_ptr<Storage::Cartridge::Cartridge>> &cartridges,
std::list<StaticAnalyser::Target> &destination)
{
// strip out inappropriate cartridges
std::list<std::shared_ptr<Storage::Cartridge::Cartridge>> acornCartridges = AcornCartridgesFrom(cartridges);
// if there are any tapes, attempt to get data from the first
if(tapes.size() > 0)
{
std::shared_ptr<Storage::Tape::Tape> tape = tapes.front();
tape->reset();
}
}