src/promemul/dreamcast.c

/*
 *  Copyright (C) 2006-2007  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 1.17 2007/06/17 23:32:20 debug Exp $
 *
 *  COMMENT: 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"


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

static int booting_from_cdrom = 0;


/*
 *  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=0; i<0x50; i+=sizeof(uint32_t)) {
                /*  Store pointer to PROM routine...  */
                store_32bit_word(cpu, 0x8c0000b0 + i, 0x8c000040 + i);

                /*  ... which contains only 1 instruction, a special
                    opcode which triggers PROM emulation:  */
                store_16bit_word(cpu, 0x8c000040 + i, SH_INVALID_INSTR);
        }

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

        dreamcast_romfont_init(machine);
}


/*
 *  dreamcast_emul():
 */
int dreamcast_emul(struct cpu *cpu)
{
        int addr = (cpu->pc & 0xff) - 0x40 + 0xb0;
        int r1 = cpu->cd.sh.r[1];
        int r6 = cpu->cd.sh.r[6];
        int r7 = cpu->cd.sh.r[7];

        /*  Special case: Reboot  */
        if ((uint32_t)cpu->pc == 0xa0000000) {
                fatal("[ dreamcast reboot ]\n");
                cpu->running = 0;
                return 1;
        }

        switch (addr) {

        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.
                 */
                if (booting_from_cdrom) {
                        fatal("[ dreamcast: Switching to bootstrap 1 ]\n");
                        booting_from_cdrom = 0;
                        cpu->pc = 0x8c00b800;
                        return 1;
                } else {
                        fatal("[ dreamcast: Returning to main menu. ]\n");
                        cpu->running = 0;
                }
                break;

        case 0xf0:
                /*
                 *  GXemul hack:
                 *
                 *  By jumping to this address (0x8c000080), a "boot from
                 *  CDROM" is simulated. Control is transfered to the license
                 *  code in the loaded IP.BIN file.
                 */
                debug("[ dreamcast boot from CDROM ]\n");
                booting_from_cdrom = 1;
                cpu->pc = 0x8c008300;
                return 1;

        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, "
            "pc=0x%08"PRIx32" ]\n", (uint32_t)cpu->pc);
        cpu->running = 0;
        return 1;
}

1	dpavlin	32	/*
2	dpavlin	34	* Copyright (C) 2006-2007 Anders Gavare. All rights reserved.
3	dpavlin	32	*
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	dpavlin	44	* $Id: dreamcast.c,v 1.17 2007/06/17 23:32:20 debug Exp $
29	dpavlin	32	*
30	dpavlin	44	* COMMENT: Dreamcast PROM emulation
31	dpavlin	32	*
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
50			/* The ROM FONT seems to be located just after 1MB, in a real Dreamcast: */
51			#define DREAMCAST_ROMFONT_BASE 0x80100020
52
53	dpavlin	34	static int booting_from_cdrom = 0;
54	dpavlin	32
55	dpavlin	34
56	dpavlin	32	/*
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	dpavlin	34	for (i=0; i<0x50; i+=sizeof(uint32_t)) {
122	dpavlin	32	/* Store pointer to PROM routine... */
123	dpavlin	34	store_32bit_word(cpu, 0x8c0000b0 + i, 0x8c000040 + i);
124	dpavlin	32
125			/* ... which contains only 1 instruction, a special
126	dpavlin	34	opcode which triggers PROM emulation: */
127			store_16bit_word(cpu, 0x8c000040 + i, SH_INVALID_INSTR);
128	dpavlin	32	}
129
130			/* PROM reboot, in case someone jumps to 0xa0000000: */
131	dpavlin	34	store_16bit_word(cpu, 0xa0000000, SH_INVALID_INSTR);
132	dpavlin	32
133			dreamcast_romfont_init(machine);
134			}
135
136
137			/*
138			* dreamcast_emul():
139			*/
140			int dreamcast_emul(struct cpu *cpu)
141			{
142	dpavlin	34	int addr = (cpu->pc & 0xff) - 0x40 + 0xb0;
143	dpavlin	32	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	dpavlin	34	/* Special case: Reboot */
148			if ((uint32_t)cpu->pc == 0xa0000000) {
149			fatal("[ dreamcast reboot ]\n");
150			cpu->running = 0;
151			return 1;
152			}
153
154	dpavlin	32	switch (addr) {
155
156			case 0xb0:
157			/* SYSINFO */
158			switch (r7) {
159			default:fatal("[ SYSINFO: Unimplemented r7=%i ]\n", r7);
160			goto bad;
161			}
162			break;
163
164			case 0xb4:
165			/* ROMFONT */
166			switch (r1) {
167			case 0: /* ROMFONT_ADDRESS */
168			cpu->cd.sh.r[0] = DREAMCAST_ROMFONT_BASE;
169			break;
170			default:fatal("[ ROMFONT: Unimplemented r1=%i ]\n", r1);
171			goto bad;
172			}
173			break;
174
175			case 0xb8:
176			/* FLASHROM */
177			switch (r7) {
178			case 0: /* FLASHROM_INFO */
179			/* TODO */
180			cpu->cd.sh.r[0] = (uint32_t) -1;
181			break;
182			default:fatal("[ FLASHROM: Unimplemented r7=%i ]\n", r7);
183			goto bad;
184			}
185			break;
186
187			case 0xbc:
188			switch ((int32_t)r6) {
189			case 0: /* GD-ROM emulation */
190			switch (r7) {
191			case 0: /* GDROM_SEND_COMMAND */
192			/* TODO */
193			cpu->cd.sh.r[0] = (uint32_t) -1;
194			break;
195			case 1: /* GDROM_CHECK_COMMAND */
196			/* TODO */
197			cpu->cd.sh.r[0] = 0;
198			break;
199			case 2: /* GDROM_MAINLOOP */
200			/* TODO */
201			break;
202			case 3: /* GDROM_INIT */
203			/* TODO: Do something here? */
204			break;
205			case 4: /* GDROM_CHECK_DRIVE */
206			/* TODO: Return status words */
207			break;
208			default:fatal("[ GDROM: Unimplemented r7=%i ]\n", r7);
209			goto bad;
210			}
211			break;
212			default:fatal("[ 0xbc: Unimplemented r6=0x%x ]\n", r6);
213			goto bad;
214			}
215			break;
216
217			case 0xe0:
218			/*
219			* This seems to have two uses:
220			*
221			* 1. KalistOS calls this from arch_menu(), i.e. to return
222			* from a running program.
223			* 2. The "licence code" in the IP.BIN code when booting from
224			* a bootable CD image calls this once the license screen
225			* has been displayed, and it wants the ROM to jump to
226			* 0x8c00b800 ("Bootstrap 1").
227			*
228			* The easiest way to support both is probably to keep track
229			* of whether the IP.BIN code was started by the (software)
230			* ROM emulation code, or not.
231	dpavlin	34	*/
232			if (booting_from_cdrom) {
233			fatal("[ dreamcast: Switching to bootstrap 1 ]\n");
234			booting_from_cdrom = 0;
235			cpu->pc = 0x8c00b800;
236			return 1;
237			} else {
238			fatal("[ dreamcast: Returning to main menu. ]\n");
239			cpu->running = 0;
240			}
241			break;
242
243			case 0xf0:
244			/*
245			* GXemul hack:
246	dpavlin	32	*
247	dpavlin	34	* By jumping to this address (0x8c000080), a "boot from
248			* CDROM" is simulated. Control is transfered to the license
249			* code in the loaded IP.BIN file.
250	dpavlin	32	*/
251	dpavlin	34	debug("[ dreamcast boot from CDROM ]\n");
252			booting_from_cdrom = 1;
253			cpu->pc = 0x8c008300;
254			return 1;
255	dpavlin	32
256			default:goto bad;
257			}
258
259			/* Return from subroutine: */
260			cpu->pc = cpu->cd.sh.pr;
261
262			return 1;
263
264			bad:
265			cpu_register_dump(cpu->machine, cpu, 1, 0);
266			printf("\n");
267	dpavlin	34	fatal("[ dreamcast_emul(): unimplemented dreamcast PROM call, "
268			"pc=0x%08"PRIx32" ]\n", (uint32_t)cpu->pc);
269	dpavlin	32	cpu->running = 0;
270			return 1;
271			}
272