src/promemul/dreamcast.c

/*
 *  Copyright (C) 2006  Anders Gavare.  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright  
 *     notice, this list of conditions and the following disclaimer in the 
 *     documentation and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 *  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE   
 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 *  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 *  OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *  HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 *  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 *  OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 *  SUCH DAMAGE.
 *
 *
 *  $Id: dreamcast.c,v 1.12 2006/11/02 06:47:14 debug Exp $
 *
 *  Dreamcast PROM emulation.
 *
 *  NOTE: This is basically just a dummy module, for now.
 *
 *  See http://mc.pp.se/dc/syscalls.html for a description of what the
 *  PROM syscalls do. (The symbolic names in this module are the same as on
 *  that page.)
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>

#include "cpu.h"
#include "machine.h"
#include "memory.h"
#include "misc.h"

#ifdef ENABLE_SH


/*  The ROM FONT seems to be located just after 1MB, in a real Dreamcast:  */
#define DREAMCAST_ROMFONT_BASE          0x80100020


/*
 *  dreamcast_romfont_init()
 *
 *  Initialize the ROM font.
 */
static void dreamcast_romfont_init(struct machine *machine)
{
        struct cpu *cpu = machine->cpus[0];
        int i, y, v;
        uint64_t d = DREAMCAST_ROMFONT_BASE;

        /*  TODO: A real font.  */

        /*  288 narrow glyphs (12 x 24 pixels):  */
        for (i=0; i<288; i++) {
                for (y=0; y<24; y+=2) {
                        if (y <= 1 || y >= 22)
                                v = 0;
                        else
                                v = random();
                        store_byte(cpu, d++, v & 0x3f);
                        store_byte(cpu, d++, v & 0xc3);
                        store_byte(cpu, d++, v & 0xfc);
                }
        }

        /*  7078 wide glyphs (24 x 24 pixels):  */
        for (i=0; i<7078; i++) {
                for (y=0; y<24; y++) {
                        if (y <= 1 || y >= 22)
                                v = 0;
                        else
                                v = random();
                        store_byte(cpu, d++, v & 0x3f);
                        store_byte(cpu, d++, v);
                        store_byte(cpu, d++, v & 0xfc);
                }
        }

        /*  129 VME icons (32 x 32 pixels):  */
        for (i=0; i<129; i++) {
                for (y=0; y<32; y++) {
                        if (y <= 1 || y >= 30)
                                v = 0;
                        else
                                v = random();
                        store_byte(cpu, d++, v & 0x3f);
                        store_byte(cpu, d++, v);
                        store_byte(cpu, d++, v);
                        store_byte(cpu, d++, v & 0xfc);
                }
        }
}


/*
 *  dreamcast_machine_setup():
 *
 *  Initializes pointers to Dreamcast PROM syscalls.
 */
void dreamcast_machine_setup(struct machine *machine)
{
        int i;
        struct cpu *cpu = machine->cpus[0];

        for (i=0xb0; i<=0xfc; i+=sizeof(uint32_t)) {
                /*  Store pointer to PROM routine...  */
                store_32bit_word(cpu, 0x8c000000 + i, 0x8c000100 + i);

                /*  ... which contains only 1 instruction, a special
                    0x00ff opcode which triggers PROM emulation:  */
                store_16bit_word(cpu, 0x8c000100 + i, 0x00ff);
        }

        /*  PROM reboot, in case someone jumps to 0xa0000000:  */
        store_16bit_word(cpu, 0xa0000000, 0x00ff);

        dreamcast_romfont_init(machine);
}


/*
 *  dreamcast_emul():
 */
int dreamcast_emul(struct cpu *cpu)
{
        int addr = cpu->pc & 0xff;
        int r1 = cpu->cd.sh.r[1];
        int r6 = cpu->cd.sh.r[6];
        int r7 = cpu->cd.sh.r[7];

        switch (addr) {

        case 0x00:
                /*  Special case: Reboot  */
                fatal("[ dreamcast reboot ]\n");
                cpu->running = 0;
                break;

        case 0xb0:
                /*  SYSINFO  */
                switch (r7) {
                default:fatal("[ SYSINFO: Unimplemented r7=%i ]\n", r7);
                        goto bad;
                }
                break;

        case 0xb4:
                /*  ROMFONT  */
                switch (r1) {
                case 0: /*  ROMFONT_ADDRESS  */
                        cpu->cd.sh.r[0] = DREAMCAST_ROMFONT_BASE;
                        break;
                default:fatal("[ ROMFONT: Unimplemented r1=%i ]\n", r1);
                        goto bad;
                }
                break;

        case 0xb8:
                /*  FLASHROM  */
                switch (r7) {
                case 0: /*  FLASHROM_INFO  */
                        /*  TODO  */
                        cpu->cd.sh.r[0] = (uint32_t) -1;
                        break;
                default:fatal("[ FLASHROM: Unimplemented r7=%i ]\n", r7);
                        goto bad;
                }
                break;

        case 0xbc:
                switch ((int32_t)r6) {
                case 0: /*  GD-ROM emulation  */
                        switch (r7) {
                        case 0: /*  GDROM_SEND_COMMAND  */
                                /*  TODO  */
                                cpu->cd.sh.r[0] = (uint32_t) -1;
                                break;
                        case 1: /*  GDROM_CHECK_COMMAND  */
                                /*  TODO  */
                                cpu->cd.sh.r[0] = 0;
                                break;
                        case 2: /*  GDROM_MAINLOOP  */
                                /*  TODO  */
                                break;
                        case 3: /*  GDROM_INIT  */
                                /*  TODO: Do something here?  */
                                break;
                        case 4: /*  GDROM_CHECK_DRIVE  */
                                /*  TODO: Return status words  */
                                break;
                        default:fatal("[ GDROM: Unimplemented r7=%i ]\n", r7);
                                goto bad;
                        }
                        break;
                default:fatal("[ 0xbc: Unimplemented r6=0x%x ]\n", r6);
                        goto bad;
                }
                break;

        case 0xe0:
                /*
                 *  This seems to have two uses:
                 *
                 *  1. KalistOS calls this from arch_menu(), i.e. to return
                 *     from a running program.
                 *  2. The "licence code" in the IP.BIN code when booting from
                 *     a bootable CD image calls this once the license screen
                 *     has been displayed, and it wants the ROM to jump to
                 *     0x8c00b800 ("Bootstrap 1").
                 *
                 *  The easiest way to support both is probably to keep track
                 *  of whether the IP.BIN code was started by the (software)
                 *  ROM emulation code, or not.
                 *
                 *  TODO
                 */
                fatal("[ Boot menu? TODO ]\n");
                goto bad;

        default:goto bad;
        }

        /*  Return from subroutine:  */
        cpu->pc = cpu->cd.sh.pr;

        return 1;

bad:
        cpu_register_dump(cpu->machine, cpu, 1, 0);
        printf("\n");
        fatal("[ dreamcast_emul(): unimplemented dreamcast PROM call ]\n");
        cpu->running = 0;
        return 1;
}


#endif  /*  ENABLE_SH  */
1	/*
2	* Copyright (C) 2006 Anders Gavare. All rights reserved.
3	*
4	* Redistribution and use in source and binary forms, with or without
5	* modification, are permitted provided that the following conditions are met:
6	*
7	* 1. Redistributions of source code must retain the above copyright
8	* notice, this list of conditions and the following disclaimer.
9	* 2. Redistributions in binary form must reproduce the above copyright
10	* notice, this list of conditions and the following disclaimer in the
11	* documentation and/or other materials provided with the distribution.
12	* 3. The name of the author may not be used to endorse or promote products
13	* derived from this software without specific prior written permission.
14	*
15	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25	* SUCH DAMAGE.
26	*
27	*
28	* $Id: dreamcast.c,v 1.12 2006/11/02 06:47:14 debug Exp $
29	*
30	* Dreamcast PROM emulation.
31	*
32	* NOTE: This is basically just a dummy module, for now.
33	*
34	* See http://mc.pp.se/dc/syscalls.html for a description of what the
35	* PROM syscalls do. (The symbolic names in this module are the same as on
36	* that page.)
37	*/
38
39	#include <stdio.h>
40	#include <stdlib.h>
41	#include <string.h>
42	#include <sys/types.h>
43
44	#include "cpu.h"
45	#include "machine.h"
46	#include "memory.h"
47	#include "misc.h"
48
49	#ifdef ENABLE_SH
50
51
52	/* The ROM FONT seems to be located just after 1MB, in a real Dreamcast: */
53	#define DREAMCAST_ROMFONT_BASE 0x80100020
54
55
56	/*
57	* dreamcast_romfont_init()
58	*
59	* Initialize the ROM font.
60	*/
61	static void dreamcast_romfont_init(struct machine *machine)
62	{
63	struct cpu *cpu = machine->cpus[0];
64	int i, y, v;
65	uint64_t d = DREAMCAST_ROMFONT_BASE;
66
67	/* TODO: A real font. */
68
69	/* 288 narrow glyphs (12 x 24 pixels): */
70	for (i=0; i<288; i++) {
71	for (y=0; y<24; y+=2) {
72	if (y <= 1 \|\| y >= 22)
73	v = 0;
74	else
75	v = random();
76	store_byte(cpu, d++, v & 0x3f);
77	store_byte(cpu, d++, v & 0xc3);
78	store_byte(cpu, d++, v & 0xfc);
79	}
80	}
81
82	/* 7078 wide glyphs (24 x 24 pixels): */
83	for (i=0; i<7078; i++) {
84	for (y=0; y<24; y++) {
85	if (y <= 1 \|\| y >= 22)
86	v = 0;
87	else
88	v = random();
89	store_byte(cpu, d++, v & 0x3f);
90	store_byte(cpu, d++, v);
91	store_byte(cpu, d++, v & 0xfc);
92	}
93	}
94
95	/* 129 VME icons (32 x 32 pixels): */
96	for (i=0; i<129; i++) {
97	for (y=0; y<32; y++) {
98	if (y <= 1 \|\| y >= 30)
99	v = 0;
100	else
101	v = random();
102	store_byte(cpu, d++, v & 0x3f);
103	store_byte(cpu, d++, v);
104	store_byte(cpu, d++, v);
105	store_byte(cpu, d++, v & 0xfc);
106	}
107	}
108	}
109
110
111	/*
112	* dreamcast_machine_setup():
113	*
114	* Initializes pointers to Dreamcast PROM syscalls.
115	*/
116	void dreamcast_machine_setup(struct machine *machine)
117	{
118	int i;
119	struct cpu *cpu = machine->cpus[0];
120
121	for (i=0xb0; i<=0xfc; i+=sizeof(uint32_t)) {
122	/* Store pointer to PROM routine... */
123	store_32bit_word(cpu, 0x8c000000 + i, 0x8c000100 + i);
124
125	/* ... which contains only 1 instruction, a special
126	0x00ff opcode which triggers PROM emulation: */
127	store_16bit_word(cpu, 0x8c000100 + i, 0x00ff);
128	}
129
130	/* PROM reboot, in case someone jumps to 0xa0000000: */
131	store_16bit_word(cpu, 0xa0000000, 0x00ff);
132
133	dreamcast_romfont_init(machine);
134	}
135
136
137	/*
138	* dreamcast_emul():
139	*/
140	int dreamcast_emul(struct cpu *cpu)
141	{
142	int addr = cpu->pc & 0xff;
143	int r1 = cpu->cd.sh.r[1];
144	int r6 = cpu->cd.sh.r[6];
145	int r7 = cpu->cd.sh.r[7];
146
147	switch (addr) {
148
149	case 0x00:
150	/* Special case: Reboot */
151	fatal("[ dreamcast reboot ]\n");
152	cpu->running = 0;
153	break;
154
155	case 0xb0:
156	/* SYSINFO */
157	switch (r7) {
158	default:fatal("[ SYSINFO: Unimplemented r7=%i ]\n", r7);
159	goto bad;
160	}
161	break;
162
163	case 0xb4:
164	/* ROMFONT */
165	switch (r1) {
166	case 0: /* ROMFONT_ADDRESS */
167	cpu->cd.sh.r[0] = DREAMCAST_ROMFONT_BASE;
168	break;
169	default:fatal("[ ROMFONT: Unimplemented r1=%i ]\n", r1);
170	goto bad;
171	}
172	break;
173
174	case 0xb8:
175	/* FLASHROM */
176	switch (r7) {
177	case 0: /* FLASHROM_INFO */
178	/* TODO */
179	cpu->cd.sh.r[0] = (uint32_t) -1;
180	break;
181	default:fatal("[ FLASHROM: Unimplemented r7=%i ]\n", r7);
182	goto bad;
183	}
184	break;
185
186	case 0xbc:
187	switch ((int32_t)r6) {
188	case 0: /* GD-ROM emulation */
189	switch (r7) {
190	case 0: /* GDROM_SEND_COMMAND */
191	/* TODO */
192	cpu->cd.sh.r[0] = (uint32_t) -1;
193	break;
194	case 1: /* GDROM_CHECK_COMMAND */
195	/* TODO */
196	cpu->cd.sh.r[0] = 0;
197	break;
198	case 2: /* GDROM_MAINLOOP */
199	/* TODO */
200	break;
201	case 3: /* GDROM_INIT */
202	/* TODO: Do something here? */
203	break;
204	case 4: /* GDROM_CHECK_DRIVE */
205	/* TODO: Return status words */
206	break;
207	default:fatal("[ GDROM: Unimplemented r7=%i ]\n", r7);
208	goto bad;
209	}
210	break;
211	default:fatal("[ 0xbc: Unimplemented r6=0x%x ]\n", r6);
212	goto bad;
213	}
214	break;
215
216	case 0xe0:
217	/*
218	* This seems to have two uses:
219	*
220	* 1. KalistOS calls this from arch_menu(), i.e. to return
221	* from a running program.
222	* 2. The "licence code" in the IP.BIN code when booting from
223	* a bootable CD image calls this once the license screen
224	* has been displayed, and it wants the ROM to jump to
225	* 0x8c00b800 ("Bootstrap 1").
226	*
227	* The easiest way to support both is probably to keep track
228	* of whether the IP.BIN code was started by the (software)
229	* ROM emulation code, or not.
230	*
231	* TODO
232	*/
233	fatal("[ Boot menu? TODO ]\n");
234	goto bad;
235
236	default:goto bad;
237	}
238
239	/* Return from subroutine: */
240	cpu->pc = cpu->cd.sh.pr;
241
242	return 1;
243
244	bad:
245	cpu_register_dump(cpu->machine, cpu, 1, 0);
246	printf("\n");
247	fatal("[ dreamcast_emul(): unimplemented dreamcast PROM call ]\n");
248	cpu->running = 0;
249	return 1;
250	}
251
252
253	#endif /* ENABLE_SH */