3 * (C) 2018 by Andreas Eversberg <jolly@eversberg.eu>
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "../libcpu/m68k.h"
24 #include "../libcpu/execute.h"
25 #include "mercenary.h"
27 #define INITIAL_STACK 0x7fffa
28 #define RESET_VECTOR 0x59484
30 /* interrupt CPU execution at special break points and tell emulation what to do */
31 const struct cpu_stop mercenary_stop_at[] = {
32 { 0x59a4e, STOP_AT_WAIT_VBL }, /* done with rendering, waiting for VBL */
33 { 0x54c26, STOP_AT_WAIT_VBL }, /* after pressing 'HELP' key before showing menu line on benson */
34 { 0x55438, STOP_AT_WAIT_VBL }, /* waiting for menu command */
35 { 0x54c2e, STOP_AT_WAIT_VBL }, /* after pressing 'HELP' key while showing menu line on benson */
36 { 0x55446, STOP_AT_WAIT_VBL }, /* after pressing 'RETURN' while game waits for other key to resume */
37 { 0x51620, STOP_AT_WAIT_VBL }, /* after dying, waiting for VBL to fade out palette */
38 { 0x0, STOP_AT_END }, /* end */
41 extern const uint32_t mercenary2_hex[];
42 extern int mercenary2_hex_size;
44 void mercenary_load(void)
48 /* load game binary from constant to volatile memory */
49 for (i = 0; i < mercenary2_hex_size; i += 4) {
50 m68k_write_memory_32(i, mercenary2_hex[i / 4]);
54 void mercenary_patch(void)
57 m68k_write_memory_32(0x00000, INITIAL_STACK);
60 m68k_write_memory_32(0x00004, RESET_VECTOR);
62 /* remove wait for VBL */
63 m68k_write_memory_16(0x59a54, 0x4e71); /* nop */
65 /* reduce loop that waits for disk stepper to move */
66 if (m68k_read_memory_32(0x55398) != 0x0000091b) {
67 fprintf(stderr, "expecting loop counter of 0x0000091b here, please fix!\n");
70 m68k_write_memory_32(0x55398, 1);
71 /* reduce loop that waits for disk side change */
72 if (m68k_read_memory_32(0x54ffc) != 0x00000d02) {
73 fprintf(stderr, "expecting loop counter of 0x00000d02 here, please fix!\n");
76 m68k_write_memory_32(0x54ffc, 1);
79 uint32_t mercenary_palette(void)
81 return m68k_read_memory_32(0x007c14);