libsidplayfp 2.3.1
SystemROMBanks.h
1/*
2 * This file is part of libsidplayfp, a SID player engine.
3 *
4 * Copyright 2012-2015 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
40template <int N>
41class romBank : public Bank
42{
43protected:
45 uint8_t rom[N];
46
47protected:
51 void setVal(uint_least16_t address, uint8_t val) { rom[address & (N-1)]=val; }
52
56 uint8_t getVal(uint_least16_t address) const { return rom[address & (N-1)]; }
57
61 void* getPtr(uint_least16_t address) const { return (void*)&rom[address & (N-1)]; }
62
63public:
67 void set(const uint8_t* source) { if (source != nullptr) memcpy(rom, source, N); }
68
72 void poke(uint_least16_t, uint8_t) override {}
73
77 uint8_t peek(uint_least16_t address) override { return rom[address & (N-1)]; }
78};
79
85class KernalRomBank final : public romBank<0x2000>
86{
87private:
88 uint8_t resetVectorLo; // 0xfffc
89 uint8_t resetVectorHi; // 0xfffd
90
91public:
92 void set(const uint8_t* kernal)
93 {
95
96 if (kernal == nullptr)
97 {
98 // IRQ entry point
99 setVal(0xffa0, PHAn); // Save regs
100 setVal(0xffa1, TXAn);
101 setVal(0xffa2, PHAn);
102 setVal(0xffa3, TYAn);
103 setVal(0xffa4, PHAn);
104 setVal(0xffa5, JMPi); // Jump to IRQ routine
105 setVal(0xffa6, 0x14);
106 setVal(0xffa7, 0x03);
107
108 // Halt
109 setVal(0xea39, 0x02);
110
111 // Hardware vectors
112 setVal(0xfffa, 0x39); // NMI vector
113 setVal(0xfffb, 0xea);
114 setVal(0xfffc, 0x39); // RESET vector
115 setVal(0xfffd, 0xea);
116 setVal(0xfffe, 0xa0); // IRQ/BRK vector
117 setVal(0xffff, 0xff);
118 }
119
120 // Backup Reset Vector
121 resetVectorLo = getVal(0xfffc);
122 resetVectorHi = getVal(0xfffd);
123 }
124
125 void reset()
126 {
127 // Restore original Reset Vector
128 setVal(0xfffc, resetVectorLo);
129 setVal(0xfffd, resetVectorHi);
130 }
131
137 void installResetHook(uint_least16_t addr)
138 {
139 setVal(0xfffc, endian_16lo8(addr));
140 setVal(0xfffd, endian_16hi8(addr));
141 }
142};
143
149class BasicRomBank final : public romBank<0x2000>
150{
151private:
152 uint8_t trap[3];
153 uint8_t subTune[11];
154
155public:
156 void set(const uint8_t* basic)
157 {
159
160 // Backup BASIC Warm Start
161 memcpy(trap, getPtr(0xa7ae), sizeof(trap));
162
163 memcpy(subTune, getPtr(0xbf53), sizeof(subTune));
164 }
165
166 void reset()
167 {
168 // Restore original BASIC Warm Start
169 memcpy(getPtr(0xa7ae), trap, sizeof(trap));
170
171 memcpy(getPtr(0xbf53), subTune, sizeof(subTune));
172 }
173
179 void installTrap(uint_least16_t addr)
180 {
181 setVal(0xa7ae, JMPw);
182 setVal(0xa7af, endian_16lo8(addr));
183 setVal(0xa7b0, endian_16hi8(addr));
184 }
185
186 void setSubtune(uint8_t tune)
187 {
188 setVal(0xbf53, LDAb);
189 setVal(0xbf54, tune);
190 setVal(0xbf55, STAa);
191 setVal(0xbf56, 0x0c);
192 setVal(0xbf57, 0x03);
193 setVal(0xbf58, JSRw);
194 setVal(0xbf59, 0x2c);
195 setVal(0xbf5a, 0xa8);
196 setVal(0xbf5b, JMPw);
197 setVal(0xbf5c, 0xb1);
198 setVal(0xbf5d, 0xa7);
199 }
200};
201
207class CharacterRomBank final : public romBank<0x1000> {};
208
209}
210
211#endif
Definition: Bank.h:36
Definition: SystemROMBanks.h:150
void installTrap(uint_least16_t addr)
Definition: SystemROMBanks.h:179
Definition: SystemROMBanks.h:207
Definition: SystemROMBanks.h:86
void installResetHook(uint_least16_t addr)
Definition: SystemROMBanks.h:137
Definition: SystemROMBanks.h:42
void set(const uint8_t *source)
Definition: SystemROMBanks.h:67
uint8_t peek(uint_least16_t address) override
Definition: SystemROMBanks.h:77
uint8_t getVal(uint_least16_t address) const
Definition: SystemROMBanks.h:56
void poke(uint_least16_t, uint8_t) override
Definition: SystemROMBanks.h:72
uint8_t rom[N]
The ROM array.
Definition: SystemROMBanks.h:45
void setVal(uint_least16_t address, uint8_t val)
Definition: SystemROMBanks.h:51
void * getPtr(uint_least16_t address) const
Definition: SystemROMBanks.h:61