1 /*
2 * UAE - The Un*x Amiga Emulator
3 *
4 * A "replacement" for a missing Kickstart
5 * Warning! Q&D
6 *
7 * (c) 1995 Bernd Schmidt
8 */
9
10 #include "sysconfig.h"
11 #include "sysdeps.h"
12
13 #include "options.h"
14 #include "uae.h"
15 #include "memory.h"
16 #include "custom.h"
17 #include "newcpu.h"
18 #include "cia.h"
19 #include "disk.h"
20 #include "ersatz.h"
21
22 #define EOP_INIT 0
23 #define EOP_NIMP 1
24 #define EOP_SERVEINT 2
25 #define EOP_DOIO 3
26 #define EOP_OPENLIB 4
27 #define EOP_AVAILMEM 5
28 #define EOP_ALLOCMEM 6
29 #define EOP_ALLOCABS 7
30 #define EOP_LOOP 8
31
32 static int already_failed = 0;
33
init_ersatz_rom(uae_u8 * data)34 void init_ersatz_rom (uae_u8 *data)
35 {
36 write_log ("Trying to use Kickstart replacement.\n");
37 *data++ = 0x00; *data++ = 0x08; /* initial SP */
38 *data++ = 0x00; *data++ = 0x00;
39 *data++ = 0x00; *data++ = 0xF8; /* initial PC */
40 *data++ = 0x00; *data++ = 0x08;
41
42 *data++ = 0xFF; *data++ = 0x0D;
43 *data++ = 0x00; *data++ = EOP_INIT;
44 *data++ = 0xFF; *data++ = 0x0D;
45 *data++ = 0x00; *data++ = EOP_NIMP;
46
47 *data++ = 0xFF; *data++ = 0x0D;
48 *data++ = 0x00; *data++ = EOP_LOOP;
49 *data++ = 0xFF; *data++ = 0x0D;
50 *data++ = 0x00; *data++ = EOP_DOIO;
51
52 *data++ = 0x4E; *data++ = 0x75;
53 *data++ = 0xFF; *data++ = 0x0D;
54 *data++ = 0x00; *data++ = EOP_SERVEINT;
55 *data++ = 0x4E; *data++ = 0x73;
56
57 *data++ = 0xFF; *data++ = 0x0D;
58 *data++ = 0x00; *data++ = EOP_AVAILMEM;
59 *data++ = 0x4E; *data++ = 0x75;
60 *data++ = 0xFF; *data++ = 0x0D;
61
62 *data++ = 0x00; *data++ = EOP_ALLOCMEM;
63 *data++ = 0x4E; *data++ = 0x75;
64 *data++ = 0xFF; *data++ = 0x0D;
65 *data++ = 0x00; *data++ = EOP_ALLOCABS;
66
67 *data++ = 0x4E; *data++ = 0x75;
68 }
69
ersatz_failed(void)70 static void ersatz_failed (void)
71 {
72 if (already_failed)
73 return;
74 already_failed = 1;
75 #if 0
76 notify_user (NUMSG_KICKREPNO);
77 uae_restart (-1, NULL);
78 #endif
79 uae_quit ();
80 }
81
ersatz_doio(void)82 static void ersatz_doio (void)
83 {
84 uaecptr request = m68k_areg (regs, 1);
85 switch (get_word (request + 0x1C)) {
86 case 9: /* TD_MOTOR is harmless */
87 case 2: case 0x8002: /* READ commands */
88 break;
89
90 default:
91 write_log ("Only CMD_READ supported in DoIO()\n");
92 ersatz_failed ();
93 }
94 {
95 uaecptr dest = get_long (request + 0x28);
96 int start = get_long (request + 0x2C) / 512;
97 int nsecs = get_long (request + 0x24) / 512;
98 int tr = start / 11;
99 int sec = start % 11;
100 while (nsecs--) {
101 DISK_ersatz_read (tr, sec, dest);
102 dest += 512;
103 if (++sec == 11)
104 sec = 0, tr++;
105 }
106 }
107 }
108
ersatz_init(void)109 static void ersatz_init (void)
110 {
111 int f;
112 uaecptr request;
113 uaecptr a;
114
115 if (disk_empty (0)) {
116 write_log ("You need to have a diskfile in DF0 to use the Kickstart replacement!\n");
117 uae_quit ();
118 m68k_setpc (0xF80010);
119 return;
120 }
121
122 regs.s = 0;
123 /* Set some interrupt vectors */
124 for (a = 8; a < 0xC0; a += 4) {
125 put_long (a, 0xF8001A);
126 }
127 regs.isp = regs.msp = regs.usp = 0x800;
128 m68k_areg (regs, 7) = 0x80000;
129 regs.intmask = 0;
130
131 /* Build a dummy execbase */
132 put_long (4, m68k_areg (regs, 6) = 0x676);
133 put_byte (0x676 + 0x129, 0);
134 for (f = 1; f < 105; f++) {
135 put_word (0x676 - 6*f, 0x4EF9);
136 put_long (0x676 - 6*f + 2, 0xF8000C);
137 }
138 /* Some "supported" functions */
139 put_long (0x676 - 456 + 2, 0xF80014);
140 put_long (0x676 - 216 + 2, 0xF80020);
141 put_long (0x676 - 198 + 2, 0xF80026);
142 put_long (0x676 - 204 + 2, 0xF8002c);
143 put_long (0x676 - 210 + 2, 0xF8002a);
144
145 /* Build an IORequest */
146 request = 0x800;
147 put_word (request + 0x1C, 2);
148 put_long (request + 0x28, 0x4000);
149 put_long (request + 0x2C, 0);
150 put_long (request + 0x24, 0x200 * 4);
151 m68k_areg (regs, 1) = request;
152 ersatz_doio ();
153 /* kickstart disk loader */
154 if (get_long (0x4000) == 0x4b49434b) {
155 /* a kickstart disk was found in drive 0! */
156 write_log ("Loading Kickstart rom image from Kickstart disk\n");
157 /* print some notes... */
158 write_log ("NOTE: if UAE crashes set CPU to 68000 and/or chipmem size to 512KB!\n");
159
160 /* read rom image from kickstart disk */
161 put_word (request + 0x1C, 2);
162 put_long (request + 0x28, 0xF80000);
163 put_long (request + 0x2C, 0x200);
164 put_long (request + 0x24, 0x200 * 512);
165 m68k_areg (regs, 1) = request;
166 ersatz_doio ();
167
168 /* read rom image once again to mirror address space.
169 not elegant, but it works... */
170 put_word (request + 0x1C, 2);
171 put_long (request + 0x28, 0xFC0000);
172 put_long (request + 0x2C, 0x200);
173 put_long (request + 0x24, 0x200 * 512);
174 m68k_areg (regs, 1) = request;
175 ersatz_doio ();
176
177 disk_eject (0);
178
179 m68k_setpc (0xFC0002);
180 fill_prefetch_slow ();
181 uae_reset (0);
182 ersatzkickfile = 0;
183 return;
184 }
185
186 m68k_setpc (0x400C);
187 fill_prefetch_slow ();
188
189 /* Init the hardware */
190 put_long (0x3000, 0xFFFFFFFEul);
191 put_long (0xDFF080, 0x3000);
192 put_word (0xDFF088, 0);
193 put_word (0xDFF096, 0xE390);
194 put_word (0xDFF09A, 0xE02C);
195 put_word (0xDFF09E, 0x0000);
196 put_word (0xDFF092, 0x0038);
197 put_word (0xDFF094, 0x00D0);
198 put_word (0xDFF08E, 0x2C81);
199 put_word (0xDFF090, 0xF4C1);
200 put_word (0xDFF02A, 0x8000);
201
202 put_byte (0xBFD100, 0xF7);
203 put_byte (0xBFEE01, 0);
204 put_byte (0xBFEF01, 0x08);
205 put_byte (0xBFDE00, 0x04);
206 put_byte (0xBFDF00, 0x84);
207 put_byte (0xBFDD00, 0x9F);
208 put_byte (0xBFED01, 0x9F);
209 }
210
ersatz_perform(uae_u16 what)211 void ersatz_perform (uae_u16 what)
212 {
213 switch (what) {
214 case EOP_INIT:
215 ersatz_init ();
216 break;
217
218 case EOP_SERVEINT:
219 /* Just reset all the interrupt request bits */
220 put_word (0xDFF09C, get_word (0xDFF01E) & 0x3FFF);
221 break;
222
223 case EOP_DOIO:
224 ersatz_doio ();
225 break;
226
227 case EOP_AVAILMEM:
228 m68k_dreg (regs, 0) = m68k_dreg (regs, 1) & 4 ? 0 : 0x70000;
229 break;
230
231 case EOP_ALLOCMEM:
232 m68k_dreg (regs, 0) = m68k_dreg (regs, 1) & 4 ? 0 : 0x0F000;
233 break;
234
235 case EOP_ALLOCABS:
236 m68k_dreg (regs, 0) = m68k_areg (regs, 1);
237 break;
238
239 case EOP_NIMP:
240 write_log ("Unimplemented Kickstart function called\n");
241 ersatz_failed ();
242 break;
243
244 /* fall through */
245 case EOP_LOOP:
246 m68k_setpc (0xF80010);
247 break;
248
249 case EOP_OPENLIB:
250 default:
251 write_log ("Internal error. Giving up.\n");
252 ersatz_failed ();
253 break;
254 }
255 }
256