1 /*
2 * stb.c - Cartridge handling, Structured Basic cart.
3 *
4 * Written by
5 * Walter Zimmer, adapted from kcs.c
6 *
7 * This file is part of VICE, the Versatile Commodore Emulator.
8 * See README for copyright notice.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
23 * 02111-1307 USA.
24 *
25 */
26
27 #include "vice.h"
28
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32
33 #define CARTRIDGE_INCLUDE_SLOTMAIN_API
34 #include "c64cartsystem.h"
35 #undef CARTRIDGE_INCLUDE_SLOTMAIN_API
36 #include "cartio.h"
37 #include "cartridge.h"
38 #include "export.h"
39 #include "monitor.h"
40 #include "snapshot.h"
41 #include "stb.h"
42 #include "types.h"
43 #include "util.h"
44 #include "crt.h"
45
46 /* Structured Basic IO1 logic for the roml range $8000-$9fff
47 *
48 * Any read/write access for IO/1 latch the lower two address bits:
49 * - bit 1 selects bank 1 of the stb rom
50 * - bit 0 and bit 1 set deactivate EXROM and expose the RAM
51 */
52
53 /* ---------------------------------------------------------------------*/
54
55 static uint8_t stb_io1_read(uint16_t addr);
56 static uint8_t stb_io1_peek(uint16_t addr);
57 static void stb_io1_store(uint16_t addr, uint8_t value);
58 static int stb_dump(void);
59
60 static io_source_t stb_device = {
61 CARTRIDGE_NAME_STRUCTURED_BASIC,
62 IO_DETACH_CART,
63 NULL,
64 0xde00, 0xdeff, 0xff,
65 0, /* read is never valid */
66 stb_io1_store,
67 stb_io1_read,
68 stb_io1_peek,
69 stb_dump,
70 CARTRIDGE_STRUCTURED_BASIC,
71 0,
72 0
73 };
74
75 static io_source_list_t *stb_list_item = NULL;
76
77 static const export_resource_t export_res = {
78 CARTRIDGE_NAME_STRUCTURED_BASIC, 1, 0, &stb_device, NULL, CARTRIDGE_STRUCTURED_BASIC
79 };
80
81 /* ---------------------------------------------------------------------*/
82
83 static int stb_bank = 0;
84 static int stb_active = 0;
85
stb_io(uint16_t addr)86 static void stb_io(uint16_t addr)
87 {
88 switch (addr & 3) {
89 /* normal config: bank 0 visible */
90 case 0:
91 case 1:
92 cart_config_changed_slotmain(0, 0, CMODE_READ);
93 stb_bank = 0;
94 stb_active = 1;
95 break;
96
97 /* bank 1 visible, gets copied to RAM during reset */
98 case 2:
99 cart_config_changed_slotmain(0 | (1 << CMODE_BANK_SHIFT), 0 | (1 << CMODE_BANK_SHIFT), CMODE_READ);
100 stb_bank = 1;
101 stb_active = 1;
102 break;
103
104 /* RAM visible, which contains bank 1 */
105 case 3:
106 cart_config_changed_slotmain(2, 2, CMODE_READ);
107 stb_bank = 1;
108 stb_active = 0;
109 break;
110 }
111 }
112
stb_io1_read(uint16_t addr)113 static uint8_t stb_io1_read(uint16_t addr)
114 {
115 stb_io(addr);
116 return 0;
117 }
118
stb_io1_peek(uint16_t addr)119 static uint8_t stb_io1_peek(uint16_t addr)
120 {
121 return 0;
122 }
123
stb_io1_store(uint16_t addr,uint8_t value)124 static void stb_io1_store(uint16_t addr, uint8_t value)
125 {
126 stb_io(addr);
127 }
128
stb_dump(void)129 static int stb_dump(void)
130 {
131 mon_out("$8000-$9FFF ROM: %s\n", (stb_active) ? "enabled" : "disabled");
132 if (stb_active) {
133 mon_out("bank: %d\n", stb_bank);
134 }
135 return 0;
136 }
137
138 /* ---------------------------------------------------------------------*/
139
stb_config_init(void)140 void stb_config_init(void)
141 {
142 /* turn on normal config: bank 0 */
143 cart_config_changed_slotmain(0, 0, CMODE_READ);
144 stb_bank = 0;
145 stb_active = 1;
146 }
147
stb_config_setup(uint8_t * rawcart)148 void stb_config_setup(uint8_t *rawcart)
149 {
150 /* copy banks 0 and 1 */
151 memcpy(roml_banks, rawcart, 0x4000);
152
153 /* turn on normal config: bank 0 */
154 cart_config_changed_slotmain(0, 0, CMODE_READ);
155 stb_bank = 0;
156 stb_active = 1;
157 }
158
159 /* ---------------------------------------------------------------------*/
160
stb_common_attach(void)161 static int stb_common_attach(void)
162 {
163 /* add export */
164 if (export_add(&export_res) < 0) {
165 return -1;
166 }
167
168 stb_list_item = io_source_register(&stb_device);
169
170 return 0;
171 }
172
stb_bin_attach(const char * filename,uint8_t * rawcart)173 int stb_bin_attach(const char *filename, uint8_t *rawcart)
174 {
175 /* load file into cartridge address space */
176 if (util_file_load(filename, rawcart, 0x4000, UTIL_FILE_LOAD_RAW) < 0) {
177 return -1;
178 }
179
180 return stb_common_attach();
181 }
182
stb_crt_attach(FILE * fd,uint8_t * rawcart)183 int stb_crt_attach(FILE *fd, uint8_t *rawcart)
184 {
185 crt_chip_header_t chip;
186
187 while (1) {
188 if (crt_read_chip_header(&chip, fd)) {
189 break;
190 }
191
192 if (chip.start != 0x8000 || chip.size != 0x2000 || chip.bank > 1) {
193 return -1;
194 }
195
196 if (crt_read_chip(rawcart, chip.bank << 13, &chip, fd)) {
197 return -1;
198 }
199 }
200
201 return stb_common_attach();
202 }
203
stb_detach(void)204 void stb_detach(void)
205 {
206 export_remove(&export_res);
207 io_source_unregister(stb_list_item);
208 stb_list_item = NULL;
209 }
210
211 /* ---------------------------------------------------------------------*/
212
213 /* CARTSTB snapshot module format:
214
215 type | name | version | description
216 --------------------------------------
217 BYTE | bank | 0.1 | current bank
218 BYTE | active | 0.1 | cartridge active flag
219 ARRAY | ROML | 0.0+ | 16384 BYTES of ROML data
220 */
221
222 static char snap_module_name[] = "CARTSTB";
223 #define SNAP_MAJOR 0
224 #define SNAP_MINOR 1
225
stb_snapshot_write_module(snapshot_t * s)226 int stb_snapshot_write_module(snapshot_t *s)
227 {
228 snapshot_module_t *m;
229
230 m = snapshot_module_create(s, snap_module_name, SNAP_MAJOR, SNAP_MINOR);
231
232 if (m == NULL) {
233 return -1;
234 }
235
236 if (0
237 || SMW_B(m, (uint8_t)stb_bank) < 0
238 || SMW_B(m, (uint8_t)stb_active) < 0
239 || SMW_BA(m, roml_banks, 0x4000) < 0) {
240 snapshot_module_close(m);
241 return -1;
242 }
243
244 return snapshot_module_close(m);
245 }
246
stb_snapshot_read_module(snapshot_t * s)247 int stb_snapshot_read_module(snapshot_t *s)
248 {
249 uint8_t vmajor, vminor;
250 snapshot_module_t *m;
251
252 m = snapshot_module_open(s, snap_module_name, &vmajor, &vminor);
253
254 if (m == NULL) {
255 return -1;
256 }
257
258 /* Do not accept versions higher than current */
259 if (vmajor > SNAP_MAJOR || vminor > SNAP_MINOR) {
260 snapshot_set_error(SNAPSHOT_MODULE_HIGHER_VERSION);
261 goto fail;
262 }
263
264 /* new in 0.1 */
265 if (SNAPVAL(vmajor, vminor, 0, 1)) {
266 if (0
267 || SMR_B_INT(m, &stb_bank) < 0
268 || SMR_B_INT(m, &stb_active) < 0) {
269 goto fail;
270 }
271 } else {
272 stb_bank = 0;
273 stb_active = 0;
274 }
275
276 if (SMR_BA(m, roml_banks, 0x4000) < 0) {
277 goto fail;
278 }
279
280 snapshot_module_close(m);
281
282 return stb_common_attach();
283
284 fail:
285 snapshot_module_close(m);
286 return -1;
287 }
288