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#define nop andeq r0, r0
  7
  8.text
  9
 10b resetBase
 11b undefBase
 12b swiBase
 13b pabtBase
 14b dabtBase
 15nop
 16b irqBase
 17b fiqBase
 18
 19resetBase:
 20mov r0, #0x8000000
 21ldrb r1, [r0, #3]
 22cmp r1, #0xEA
 23ldrne r0, =0x20000C0
 24bx r0
 25.word 0
 26.word 0xE129F000
 27
 28.word 0 @ Padding for back-compat
 29
 30swiBase:
 31cmp    sp, #0
 32moveq  sp, #0x04000000
 33subeq  sp, #0x20
 34stmfd  sp!, {r4, r11-r12, lr}
 35ldrb   r11, [lr, #-2]
 36mov    r12, #swiTable
 37ldr    r11, [r12, r11, lsl #2]
 38mov    r12, #StallCall
 39cmp    r12, r11
 40swieq  0xF00000  @ Special mGBA-internal call to load the stall count into r4
 41mrs    r12, spsr
 42stmfd  sp!, {r12}
 43and    r12, #0x80
 44orr    r12, #0x1F
 45msr    cpsr_c, r12
 46stmfd  sp!, {lr}
 47cmp    r11, #0
 48nop
 49nop
 50nop
 51nop
 52nop
 53nop
 54mov    lr, pc
 55bxne   r11
 56nop
 57nop
 58nop
 59ldmfd  sp!, {lr}
 60msr    cpsr, #0x93
 61ldmfd  sp!, {r12}
 62msr    spsr, r12
 63ldmfd  sp!, {r4, r11-r12, lr}
 64movs   pc, lr
 65.word 0
 66.word 0xE3A02004
 67
 68.word 0 @ Padding for back-compat
 69
 70swiTable:
 71.word SoftReset               @ 0x00
 72.word RegisterRamReset        @ 0x01
 73.word Halt                    @ 0x02
 74.word Stop                    @ 0x03
 75.word IntrWait                @ 0x04
 76.word VBlankIntrWait          @ 0x05
 77.word Div                     @ 0x06
 78.word DivArm                  @ 0x07
 79.word Sqrt                    @ 0x08
 80.word ArcTan                  @ 0x09
 81.word ArcTan2                 @ 0x0A
 82.word CpuSet                  @ 0x0B
 83.word CpuFastSet              @ 0x0C
 84.word GetBiosChecksum         @ 0x0D
 85.word BgAffineSet             @ 0x0E
 86.word ObjAffineSet            @ 0x0F
 87.word BitUnPack               @ 0x10
 88.word Lz77UnCompWram          @ 0x11
 89.word Lz77UnCompVram          @ 0x12
 90.word HuffmanUnComp           @ 0x13
 91.word RlUnCompWram            @ 0x14
 92.word RlUnCompVram            @ 0x15
 93.word Diff8BitUnFilterWram    @ 0x16
 94.word Diff8BitUnFilterVram    @ 0x17
 95.word Diff16BitUnFilter       @ 0x18
 96.word SoundBias               @ 0x19
 97.word SoundDriverInit         @ 0x1A
 98.word SoundDriverMode         @ 0x1B
 99.word SoundDriverMain         @ 0x1C
100.word SoundDriverVsync        @ 0x1D
101.word SoundChannelClear       @ 0x1E
102.word MidiKey2Freq            @ 0x1F
103.word MusicPlayerOpen         @ 0x20
104.word MusicPlayerStart        @ 0x21
105.word MusicPlayerStop         @ 0x22
106.word MusicPlayerContinue     @ 0x23
107.word MusicPlayerFadeOut      @ 0x24
108.word MultiBoot               @ 0x25
109.word HardReset               @ 0x26
110.word CustomHalt              @ 0x27
111.word SoundDriverVsyncOff     @ 0x28
112.word SoundDriverVsyncOn      @ 0x29
113.word SoundDriverGetJumpList  @ 0x2A
114
115.ltorg
116
117irqBase:
118stmfd  sp!, {r0-r3, r12, lr}
119mov    r0, #0x04000000
120add    lr, pc, #0
121ldr    pc, [r0, #-4]
122ldmfd  sp!, {r0-r3, r12, lr}
123subs   pc, lr, #4
124.word 0
125.word 0xE55EC002
126
127undefBase:
128subs   pc, lr, #4
129.word 0
130.word 0x03A0E004
131
132@ Unimplemented
133SoftReset:
134RegisterRamReset:
135Stop:
136GetBiosChecksum:
137BgAffineSet:
138ObjAffineSet:
139BitUnPack:
140Lz77UnCompWram:
141Lz77UnCompVram:
142HuffmanUnComp:
143RlUnCompWram:
144RlUnCompVram:
145Diff8BitUnFilterWram:
146Diff8BitUnFilterVram:
147Diff16BitUnFilter:
148SoundBias:
149SoundDriverInit:
150SoundDriverMode:
151SoundDriverMain:
152SoundDriverVsync:
153SoundChannelClear:
154MidiKey2Freq:
155MusicPlayerOpen:
156MusicPlayerStart:
157MusicPlayerStop:
158MusicPlayerContinue:
159MusicPlayerFadeOut:
160MultiBoot:
161HardReset:
162CustomHalt:
163SoundDriverVsyncOff:
164SoundDriverVsyncOn:
165
166NopCall:
167bx lr
168
169Halt:
170mov    r11, #0
171mov    r12, #0x04000000
172strb   r11, [r12, #0x301]
173bx     lr
174
175VBlankIntrWait:
176mov    r0, #1
177mov    r1, #1
178IntrWait:
179stmfd  sp!, {r2-r3, lr}
180mov    r12, #0x04000000
181@ See if we want to return immediately
182cmp    r0, #0
183mov    r0, #0
184mov    r2, #1
185beq    1f
186ldrh   r3, [r12, #-8]
187bic    r3, r1
188strh   r3, [r12, #-8]
189@ Halt
1900:
191strb   r0, [r12, #0x301]
1921:
193@ Check which interrupts were acknowledged
194strb   r0, [r12, #0x208]
195ldrh   r3, [r12, #-8]
196ands   r3, r1
197eorne  r3, r1
198strneh r3, [r12, #-8]
199strb   r2, [r12, #0x208]
200beq    0b
201ldmfd  sp!, {r2-r3, pc}
202
203CpuSet:
204stmfd  sp!, {r4, r5, lr}
205mov    r4, r2, lsl #12
206mov    r12, r0
207mov    r5, r1
208tst    r2, #0x01000000
209beq    0f
210@ Fill
211tst    r2, #0x04000000
212beq    1f
213@ Word
214add    r4, r5, r4, lsr #10
215ldmia  r12!, {r3}
2162:
217cmp    r5, r4
218stmltia  r5!, {r3}
219blt    2b
220b      3f
221@ Halfword
2221:
223bic    r12, #1
224bic    r5, #1
225add    r4, r5, r4, lsr #11
226ldrh   r3, [r12]
2272:
228cmp    r5, r4
229strlth r3, [r5], #2
230blt    2b
231b      3f
232@ Copy
2330:
234tst    r2, #0x04000000
235beq    1f
236@ Word
237add    r4, r5, r4, lsr #10
2382:
239cmp    r5, r4
240ldmltia r12!, {r3}
241stmltia r5!, {r3}
242blt    2b
243b      3f
244@ Halfword
2451:
246add    r4, r5, r4, lsr #11
2472:
248cmp    r5, r4
249ldrlth r3, [r12], #2
250strlth r3, [r5], #2
251blt    2b
2523:
253mov    r3, #0x170  @ Match official BIOS's clobbered r3
254ldmfd  sp!, {r4, r5, pc}
255
256CpuFastSet:
257stmfd  sp!, {r4-r10, lr}
258tst    r2, #0x01000000
259mov    r3, r2, lsl #12
260add    r2, r1, r3, lsr #10
261beq    0f
262@ Fill
263ldr    r3, [r0]
264mov    r4, r3
265mov    r5, r3
266mov    r6, r3
267mov    r7, r3
268mov    r8, r3
269mov    r9, r3
270mov    r10, r3
2711:
272cmp    r1, r2
273stmltia r1!, {r3-r10}
274blt    1b
275b      2f
276@ Copy
2770:
278cmp    r1, r2
279ldmltia r0!, {r3-r10}
280stmltia r1!, {r3-r10}
281blt    0b
2822:
283ldmfd  sp!, {r4-r10, pc}
284
285SoundDriverGetJumpList:
286stmfd  sp!, {r4-r10}
287ldr    r1, =NopCall
288mov    r3, r1
289mov    r4, r1
290mov    r5, r1
291mov    r6, r1
292mov    r7, r1
293mov    r8, r1
294mov    r9, r1
295mov    r10, r1
296stmia  r0!, {r1, r3-r10}
297stmia  r0!, {r1, r3-r10}
298stmia  r0!, {r1, r3-r10}
299stmia  r0!, {r1, r3-r10}
300mov    r1, #0
301ldmfd  sp!, {r4-r10}
302bx     lr
303
304.ltorg
305
306Div:
307DivArm:
308Sqrt:
309ArcTan:
310ArcTan2:
311
312StallCall:
313subs r4, #4
314bhi StallCall
315bx lr