libsidplayfp 2.4.2
SystemROMBanks.h
1/*
2 * This file is part of libsidplayfp, a SID player engine.
3 *
4 * Copyright 2012-2022 Leandro Nini <drfiemost@users.sourceforge.net>
5 * Copyright 2010 Antti Lankila
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20 */
21
22#ifndef SYSTEMROMBANKS_H
23#define SYSTEMROMBANKS_H
24
25#include <stdint.h>
26#include <cstring>
27
28#include "Bank.h"
29#include "c64/CPU/opcodes.h"
30
31#include "sidcxx11.h"
32
33namespace libsidplayfp
34{
35
39template <int N>
40class romBank : public Bank
41{
42#ifdef HAVE_CXX11
43 static_assert((N != 0) && ((N & (N - 1)) == 0), "N must be a power of two");
44#endif
45
46protected:
48 uint8_t rom[N];
49
50protected:
54 void setVal(uint_least16_t address, uint8_t val) { rom[address & (N-1)]=val; }
55
59 uint8_t getVal(uint_least16_t address) const { return rom[address & (N-1)]; }
60
64 void* getPtr(uint_least16_t address) const { return (void*)&rom[address & (N-1)]; }
65
66public:
70 void set(const uint8_t* source) { if (source != nullptr) memcpy(rom, source, N); }
71
75 void poke(uint_least16_t, uint8_t) override {}
76
80 uint8_t peek(uint_least16_t address) override { return rom[address & (N-1)]; }
81};
82
88class KernalRomBank final : public romBank<0x2000>
89{
90private:
91 uint8_t resetVectorLo; // 0xfffc
92 uint8_t resetVectorHi; // 0xfffd
93
94public:
95 void set(const uint8_t* kernal)
96 {
98
99 if (kernal == nullptr)
100 {
101 // IRQ entry point
102 setVal(0xffa0, PHAn); // Save regs
103 setVal(0xffa1, TXAn);
104 setVal(0xffa2, PHAn);
105 setVal(0xffa3, TYAn);
106 setVal(0xffa4, PHAn);
107 setVal(0xffa5, JMPi); // Jump to IRQ routine
108 setVal(0xffa6, 0x14);
109 setVal(0xffa7, 0x03);
110
111 // Halt
112 setVal(0xea39, 0x02);
113
114 // Hardware vectors
115 setVal(0xfffa, 0x39); // NMI vector
116 setVal(0xfffb, 0xea);
117 setVal(0xfffc, 0x39); // RESET vector
118 setVal(0xfffd, 0xea);
119 setVal(0xfffe, 0xa0); // IRQ/BRK vector
120 setVal(0xffff, 0xff);
121 }
122
123 // Backup Reset Vector
124 resetVectorLo = getVal(0xfffc);
125 resetVectorHi = getVal(0xfffd);
126 }
127
128 void reset()
129 {
130 // Restore original Reset Vector
131 setVal(0xfffc, resetVectorLo);
132 setVal(0xfffd, resetVectorHi);
133 }
134
140 void installResetHook(uint_least16_t addr)
141 {
142 setVal(0xfffc, endian_16lo8(addr));
143 setVal(0xfffd, endian_16hi8(addr));
144 }
145};
146
152class BasicRomBank final : public romBank<0x2000>
153{
154private:
155 uint8_t trap[3];
156 uint8_t subTune[11];
157
158public:
159 void set(const uint8_t* basic)
160 {
162
163 // Backup BASIC Warm Start
164 memcpy(trap, getPtr(0xa7ae), sizeof(trap));
165
166 memcpy(subTune, getPtr(0xbf53), sizeof(subTune));
167 }
168
169 void reset()
170 {
171 // Restore original BASIC Warm Start
172 memcpy(getPtr(0xa7ae), trap, sizeof(trap));
173
174 memcpy(getPtr(0xbf53), subTune, sizeof(subTune));
175 }
176
182 void installTrap(uint_least16_t addr)
183 {
184 setVal(0xa7ae, JMPw);
185 setVal(0xa7af, endian_16lo8(addr));
186 setVal(0xa7b0, endian_16hi8(addr));
187 }
188
189 void setSubtune(uint8_t tune)
190 {
191 setVal(0xbf53, LDAb);
192 setVal(0xbf54, tune);
193 setVal(0xbf55, STAa);
194 setVal(0xbf56, 0x0c);
195 setVal(0xbf57, 0x03);
196 setVal(0xbf58, JSRw);
197 setVal(0xbf59, 0x2c);
198 setVal(0xbf5a, 0xa8);
199 setVal(0xbf5b, JMPw);
200 setVal(0xbf5c, 0xb1);
201 setVal(0xbf5d, 0xa7);
202 }
203};
204
210class CharacterRomBank final : public romBank<0x1000> {};
211
212}
213
214#endif
Definition Bank.h:36
Definition SystemROMBanks.h:153
void installTrap(uint_least16_t addr)
Definition SystemROMBanks.h:182
Definition SystemROMBanks.h:210
Definition SystemROMBanks.h:89
void installResetHook(uint_least16_t addr)
Definition SystemROMBanks.h:140
Definition SystemROMBanks.h:41
void set(const uint8_t *source)
Definition SystemROMBanks.h:70
uint8_t peek(uint_least16_t address) override
Definition SystemROMBanks.h:80
uint8_t getVal(uint_least16_t address) const
Definition SystemROMBanks.h:59
void poke(uint_least16_t, uint8_t) override
Definition SystemROMBanks.h:75
uint8_t rom[N]
The ROM array.
Definition SystemROMBanks.h:48
void setVal(uint_least16_t address, uint8_t val)
Definition SystemROMBanks.h:54
void * getPtr(uint_least16_t address) const
Definition SystemROMBanks.h:64