src/gba/gba-bios.c (view raw)
1/* Copyright (c) 2013-2014 Jeffrey Pfau
2 *
3 * This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6#include "gba-bios.h"
7
8#include "gba.h"
9#include "gba-io.h"
10#include "gba-memory.h"
11
12const uint32_t GBA_BIOS_CHECKSUM = 0xBAAE187F;
13const uint32_t GBA_DS_BIOS_CHECKSUM = 0xBAAE1880;
14
15static void _unLz77(struct GBA* gba, uint32_t source, uint32_t dest, int width);
16static void _unHuffman(struct GBA* gba, uint32_t source, uint32_t dest);
17static void _unRl(struct GBA* gba, uint32_t source, uint32_t dest, int width);
18
19static void _RegisterRamReset(struct GBA* gba) {
20 uint32_t registers = gba->cpu->gprs[0];
21 UNUSED(registers);
22 GBALog(gba, GBA_LOG_STUB, "RegisterRamReset unimplemented");
23}
24
25static void _BgAffineSet(struct GBA* gba) {
26 struct ARMCore* cpu = gba->cpu;
27 int i = cpu->gprs[2];
28 float ox, oy;
29 float cx, cy;
30 float sx, sy;
31 float theta;
32 int offset = cpu->gprs[0];
33 int destination = cpu->gprs[1];
34 float a, b, c, d;
35 float rx, ry;
36 while (i--) {
37 // [ sx 0 0 ] [ cos(theta) -sin(theta) 0 ] [ 1 0 cx - ox ] [ A B rx ]
38 // [ 0 sy 0 ] * [ sin(theta) cos(theta) 0 ] * [ 0 1 cy - oy ] = [ C D ry ]
39 // [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ] [ 0 0 1 ]
40 ox = cpu->memory.load32(cpu, offset, 0) / 256.f;
41 oy = cpu->memory.load32(cpu, offset + 4, 0) / 256.f;
42 cx = cpu->memory.load16(cpu, offset + 8, 0);
43 cy = cpu->memory.load16(cpu, offset + 10, 0);
44 sx = cpu->memory.load16(cpu, offset + 12, 0) / 256.f;
45 sy = cpu->memory.load16(cpu, offset + 14, 0) / 256.f;
46 theta = (cpu->memory.loadU16(cpu, offset + 16, 0) >> 8) / 128.f * M_PI;
47 offset += 20;
48 // Rotation
49 a = d = cosf(theta);
50 b = c = sinf(theta);
51 // Scale
52 a *= sx;
53 b *= -sx;
54 c *= sy;
55 d *= sy;
56 // Translate
57 rx = ox - (a * cx + b * cy);
58 ry = oy - (c * cx + d * cy);
59 cpu->memory.store16(cpu, destination, a * 256, 0);
60 cpu->memory.store16(cpu, destination + 2, b * 256, 0);
61 cpu->memory.store16(cpu, destination + 4, c * 256, 0);
62 cpu->memory.store16(cpu, destination + 6, d * 256, 0);
63 cpu->memory.store32(cpu, destination + 8, rx * 256, 0);
64 cpu->memory.store32(cpu, destination + 12, ry * 256, 0);
65 destination += 16;
66 }
67}
68
69static void _ObjAffineSet(struct GBA* gba) {
70 struct ARMCore* cpu = gba->cpu;
71 int i = cpu->gprs[2];
72 float sx, sy;
73 float theta;
74 int offset = cpu->gprs[0];
75 int destination = cpu->gprs[1];
76 int diff = cpu->gprs[3];
77 float a, b, c, d;
78 while (i--) {
79 // [ sx 0 ] [ cos(theta) -sin(theta) ] [ A B ]
80 // [ 0 sy ] * [ sin(theta) cos(theta) ] = [ C D ]
81 sx = cpu->memory.load16(cpu, offset, 0) / 256.f;
82 sy = cpu->memory.load16(cpu, offset + 2, 0) / 256.f;
83 theta = (cpu->memory.loadU16(cpu, offset + 4, 0) >> 8) / 128.f * M_PI;
84 offset += 8;
85 // Rotation
86 a = d = cosf(theta);
87 b = c = sinf(theta);
88 // Scale
89 a *= sx;
90 b *= -sx;
91 c *= sy;
92 d *= sy;
93 cpu->memory.store16(cpu, destination, a * 256, 0);
94 cpu->memory.store16(cpu, destination + diff, b * 256, 0);
95 cpu->memory.store16(cpu, destination + diff * 2, c * 256, 0);
96 cpu->memory.store16(cpu, destination + diff * 3, d * 256, 0);
97 destination += diff * 4;
98 }
99}
100
101static void _MidiKey2Freq(struct GBA* gba) {
102 struct ARMCore* cpu = gba->cpu;
103 uint32_t key = cpu->memory.load32(cpu, cpu->gprs[0] + 4, 0);
104 cpu->gprs[0] = key / powf(2, (180.f - cpu->gprs[1] - cpu->gprs[2] / 256.f) / 12.f);
105}
106
107static void _Div(struct GBA* gba, int32_t num, int32_t denom) {
108 struct ARMCore* cpu = gba->cpu;
109 if (denom != 0) {
110 div_t result = div(num, denom);
111 cpu->gprs[0] = result.quot;
112 cpu->gprs[1] = result.rem;
113 cpu->gprs[3] = abs(result.quot);
114 } else {
115 GBALog(gba, GBA_LOG_GAME_ERROR, "Attempting to divide %i by zero!", num);
116 // If abs(num) > 1, this should hang, but that would be painful to
117 // emulate in HLE, and no game will get into a state where it hangs...
118 cpu->gprs[0] = (num < 0) ? -1 : 1;
119 cpu->gprs[1] = num;
120 cpu->gprs[3] = 1;
121 }
122}
123
124void GBASwi16(struct ARMCore* cpu, int immediate) {
125 struct GBA* gba = (struct GBA*) cpu->master;
126 GBALog(gba, GBA_LOG_SWI, "SWI: %02X r0: %08X r1: %08X r2: %08X r3: %08X",
127 immediate, cpu->gprs[0], cpu->gprs[1], cpu->gprs[2], cpu->gprs[3]);
128
129 if (gba->memory.fullBios) {
130 ARMRaiseSWI(cpu);
131 return;
132 }
133 switch (immediate) {
134 case 0x1:
135 _RegisterRamReset(gba);
136 break;
137 case 0x2:
138 GBAHalt(gba);
139 break;
140 case 0x05:
141 // VBlankIntrWait
142 // Fall through:
143 case 0x04:
144 // IntrWait
145 ARMRaiseSWI(cpu);
146 break;
147 case 0x6:
148 _Div(gba, cpu->gprs[0], cpu->gprs[1]);
149 break;
150 case 0x7:
151 _Div(gba, cpu->gprs[1], cpu->gprs[0]);
152 break;
153 case 0x8:
154 cpu->gprs[0] = sqrt(cpu->gprs[0]);
155 break;
156 case 0xA:
157 cpu->gprs[0] = atan2f(cpu->gprs[1] / 16384.f, cpu->gprs[0] / 16384.f) / (2 * M_PI) * 0x10000;
158 break;
159 case 0xB:
160 case 0xC:
161 ARMRaiseSWI(cpu);
162 break;
163 case 0xD:
164 cpu->gprs[0] = GBAChecksum(gba->memory.bios, SIZE_BIOS);
165 case 0xE:
166 _BgAffineSet(gba);
167 break;
168 case 0xF:
169 _ObjAffineSet(gba);
170 break;
171 case 0x11:
172 case 0x12:
173 if (cpu->gprs[0] < BASE_WORKING_RAM) {
174 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 source");
175 }
176 switch (cpu->gprs[1] >> BASE_OFFSET) {
177 default:
178 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad LZ77 destination");
179 case REGION_WORKING_RAM:
180 case REGION_WORKING_IRAM:
181 case REGION_VRAM:
182 _unLz77(gba, cpu->gprs[0], cpu->gprs[1], immediate == 0x11 ? 1 : 2);
183 break;
184 }
185 break;
186 case 0x13:
187 if (cpu->gprs[0] < BASE_WORKING_RAM) {
188 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman source");
189 }
190 switch (cpu->gprs[1] >> BASE_OFFSET) {
191 default:
192 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad Huffman destination");
193 case REGION_WORKING_RAM:
194 case REGION_WORKING_IRAM:
195 case REGION_VRAM:
196 _unHuffman(gba, cpu->gprs[0], cpu->gprs[1]);
197 break;
198 }
199 break;
200 case 0x14:
201 case 0x15:
202 if (cpu->gprs[0] < BASE_WORKING_RAM) {
203 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL source");
204 }
205 switch (cpu->gprs[1] >> BASE_OFFSET) {
206 default:
207 GBALog(gba, GBA_LOG_GAME_ERROR, "Bad RL destination");
208 case REGION_WORKING_RAM:
209 case REGION_WORKING_IRAM:
210 case REGION_VRAM:
211 _unRl(gba, cpu->gprs[0], cpu->gprs[1], immediate == 0x14 ? 1 : 2);
212 break;
213 }
214 break;
215 case 0x1F:
216 _MidiKey2Freq(gba);
217 break;
218 default:
219 GBALog(gba, GBA_LOG_STUB, "Stub software interrupt: %02X", immediate);
220 }
221}
222
223void GBASwi32(struct ARMCore* cpu, int immediate) {
224 GBASwi16(cpu, immediate >> 16);
225}
226
227uint32_t GBAChecksum(uint32_t* memory, size_t size) {
228 size_t i;
229 uint32_t sum = 0;
230 for (i = 0; i < size; i += 4) {
231 sum += memory[i >> 2];
232 }
233 return sum;
234}
235
236static void _unLz77(struct GBA* gba, uint32_t source, uint32_t dest, int width) {
237 struct ARMCore* cpu = gba->cpu;
238 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
239 // We assume the signature byte (0x10) is correct
240 int blockheader = 0; // Some compilers warn if this isn't set, even though it's trivially provably always set
241 uint32_t sPointer = source + 4;
242 uint32_t dPointer = dest;
243 int blocksRemaining = 0;
244 int block;
245 uint32_t disp;
246 int bytes;
247 int byte;
248 int halfword;
249 while (remaining > 0) {
250 if (blocksRemaining) {
251 if (blockheader & 0x80) {
252 // Compressed
253 block = cpu->memory.loadU8(cpu, sPointer, 0) | (cpu->memory.loadU8(cpu, sPointer + 1, 0) << 8);
254 sPointer += 2;
255 disp = dPointer - (((block & 0x000F) << 8) | ((block & 0xFF00) >> 8)) - 1;
256 bytes = ((block & 0x00F0) >> 4) + 3;
257 while (bytes-- && remaining) {
258 --remaining;
259 byte = cpu->memory.loadU8(cpu, disp, 0);
260 ++disp;
261 if (width == 2) {
262 if (dPointer & 1) {
263 halfword |= byte << 8;
264 cpu->memory.store16(cpu, dPointer ^ 1, halfword, 0);
265 } else {
266 halfword = byte;
267 }
268 } else {
269 cpu->memory.store8(cpu, dPointer, byte, 0);
270 }
271 ++dPointer;
272 }
273 } else {
274 // Uncompressed
275 byte = cpu->memory.loadU8(cpu, sPointer, 0);
276 ++sPointer;
277 if (width == 2) {
278 if (dPointer & 1) {
279 halfword |= byte << 8;
280 cpu->memory.store16(cpu, dPointer ^ 1, halfword, 0);
281 } else {
282 halfword = byte;
283 }
284 } else {
285 cpu->memory.store8(cpu, dPointer, byte, 0);
286 }
287 ++dPointer;
288 --remaining;
289 }
290 blockheader <<= 1;
291 --blocksRemaining;
292 } else {
293 blockheader = cpu->memory.loadU8(cpu, sPointer, 0);
294 ++sPointer;
295 blocksRemaining = 8;
296 }
297 }
298}
299
300DECL_BITFIELD(HuffmanNode, uint8_t);
301DECL_BITS(HuffmanNode, Offset, 0, 6);
302DECL_BIT(HuffmanNode, RTerm, 6);
303DECL_BIT(HuffmanNode, LTerm, 7);
304
305static void _unHuffman(struct GBA* gba, uint32_t source, uint32_t dest) {
306 struct ARMCore* cpu = gba->cpu;
307 source = source & 0xFFFFFFFC;
308 uint32_t header = cpu->memory.load32(cpu, source, 0);
309 int remaining = header >> 8;
310 int bits = header & 0xF;
311 if (32 % bits) {
312 GBALog(gba, GBA_LOG_STUB, "Unimplemented unaligned Huffman");
313 return;
314 }
315 int padding = (4 - remaining) & 0x3;
316 remaining &= 0xFFFFFFFC;
317 // We assume the signature byte (0x20) is correct
318 int treesize = (cpu->memory.loadU8(cpu, source + 4, 0) << 1) + 1;
319 int block = 0;
320 uint32_t treeBase = source + 5;
321 uint32_t sPointer = source + 5 + treesize;
322 uint32_t dPointer = dest;
323 uint32_t nPointer = treeBase;
324 HuffmanNode node;
325 int bitsRemaining;
326 int readBits;
327 int bitsSeen = 0;
328 node = cpu->memory.load8(cpu, nPointer, 0);
329 while (remaining > 0) {
330 uint32_t bitstream = cpu->memory.load32(cpu, sPointer, 0);
331 sPointer += 4;
332 for (bitsRemaining = 32; bitsRemaining > 0 && remaining > 0; --bitsRemaining, bitstream <<= 1) {
333 uint32_t next = (nPointer & ~1) + HuffmanNodeGetOffset(node) * 2 + 2;
334 if (bitstream & 0x80000000) {
335 // Go right
336 if (HuffmanNodeIsRTerm(node)) {
337 readBits = cpu->memory.load8(cpu, next + 1, 0);
338 } else {
339 nPointer = next + 1;
340 node = cpu->memory.load8(cpu, nPointer, 0);
341 continue;
342 }
343 } else {
344 // Go left
345 if (HuffmanNodeIsLTerm(node)) {
346 readBits = cpu->memory.load8(cpu, next, 0);
347 } else {
348 nPointer = next;
349 node = cpu->memory.load8(cpu, nPointer, 0);
350 continue;
351 }
352 }
353
354 block |= (readBits & ((1 << bits) - 1)) << bitsSeen;
355 bitsSeen += bits;
356 nPointer = treeBase;
357 node = cpu->memory.load8(cpu, nPointer, 0);
358 if (bitsSeen == 32) {
359 bitsSeen = 0;
360 cpu->memory.store32(cpu, dPointer, block, 0);
361 dPointer += 4;
362 remaining -= 4;
363 block = 0;
364 }
365 }
366
367 }
368 if (padding) {
369 cpu->memory.store32(cpu, dPointer, block, 0);
370 }
371}
372
373static void _unRl(struct GBA* gba, uint32_t source, uint32_t dest, int width) {
374 struct ARMCore* cpu = gba->cpu;
375 source = source & 0xFFFFFFFC;
376 int remaining = (cpu->memory.load32(cpu, source, 0) & 0xFFFFFF00) >> 8;
377 int padding = (4 - remaining) & 0x3;
378 // We assume the signature byte (0x30) is correct
379 int blockheader;
380 int block;
381 uint32_t sPointer = source + 4;
382 uint32_t dPointer = dest;
383 int halfword = 0;
384 while (remaining > 0) {
385 blockheader = cpu->memory.loadU8(cpu, sPointer++, 0);
386 if (blockheader & 0x80) {
387 // Compressed
388 blockheader &= 0x7F;
389 blockheader += 3;
390 block = cpu->memory.loadU8(cpu, sPointer++, 0);
391 while (blockheader-- && remaining) {
392 --remaining;
393 if (width == 2) {
394 if (dPointer & 1) {
395 halfword |= block << 8;
396 cpu->memory.store16(cpu, dPointer ^ 1, halfword, 0);
397 } else {
398 halfword = block;
399 }
400 } else {
401 cpu->memory.store8(cpu, dPointer, block, 0);
402 }
403 ++dPointer;
404 }
405 } else {
406 // Uncompressed
407 blockheader++;
408 while (blockheader-- && remaining) {
409 --remaining;
410 int byte = cpu->memory.loadU8(cpu, sPointer, 0);
411 ++sPointer;
412 if (width == 2) {
413 if (dPointer & 1) {
414 halfword |= byte << 8;
415 cpu->memory.store16(cpu, dPointer ^ 1, halfword, 0);
416 } else {
417 halfword = byte;
418 }
419 } else {
420 cpu->memory.store8(cpu, dPointer, byte, 0);
421 }
422 ++dPointer;
423 }
424 }
425 }
426 if (width == 2) {
427 if (dPointer & 1) {
428 --padding;
429 ++dPointer;
430 }
431 for (; padding > 0; padding -= 2, dPointer += 2) {
432 cpu->memory.store16(cpu, dPointer, 0, 0);
433 }
434 } else {
435 while (padding--) {
436 cpu->memory.store8(cpu, dPointer, 0, 0);
437 ++dPointer;
438 }
439 }
440}