megaed-sv: move most start code to ROM
[megadrive.git] / megaed-sv / asmtools.s
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CommitLineData
1# Assemble with gas
2# --register-prefix-optional --bitwise-or
3
4.macro ldarg arg, stacksz, reg
5 move.l (4 + \arg * 4 + \stacksz)(%sp), \reg
6.endm
7
8
9.global read_joy_responses /* u8 *rbuf */
10read_joy_responses:
11 ldarg 0, 0, a1
12 movem.l d2-d7, -(sp)
13 movea.l #0xa10003, a0
14 move.b #0x40, (6,a0)
15 move.b #0x40, (a0)
16
17.macro one_test val
18 move.l #100/12-1, d0
190:
20 dbra d0, 0b
21 move.b \val, d0
22 move.b d0, (a0)
23 move.b (a0), d0
24 move.b (a0), d1
25 move.b (a0), d2
26 move.b (a0), d3
27 move.b (a0), d4
28 move.b (a0), d5
29 move.b (a0), d6
30 move.b (a0), d7
31 move.b d0, (a1)+
32 move.b d1, (a1)+
33 move.b d2, (a1)+
34 move.b d3, (a1)+
35 move.b d4, (a1)+
36 move.b d5, (a1)+
37 move.b d6, (a1)+
38 move.b d7, (a1)+
39.endm
40
41 move.w #0x2700, sr
42 one_test #0x00
43 one_test #0x40
44 one_test #0x00
45 one_test #0x40
46 one_test #0x00
47 move.w #0x2000, sr
48 movem.l (sp)+, d2-d7
49 rts
50
51
52/* expects:
53 * a0 = #0xa10003
54 * d0 = #0
55 * d1 = #0x40
56 * trashes d2, d3
57 */
58sync_with_teensy:
590: /* wait for special code */
60 move.b d1, (a0)
61 move.b (a0), d2
62 move.b d0, (a0)
63 move.b (a0), d3
64 and.b #0x3f, d2
65 cmp.b d2, d3
66 bne 0b
67 cmp.b #0x25, d2
68 bne 0b
69
700: /* wait for special code to end */
71 cmp.b (a0), d2
72 beq 0b
73
74 move.b d1, (a0)
75 move.l #8000000/50/18, d2
76
770: /* wait enough for teensy to setup it's stuff */
78 subq.l #1, d2 /* 8 */
79 bgt.s 0b /* 10 */
80
81 rts
82
83
84.macro t_nop
85 /*
86 * when communicating with 3.3V teensy:
87 * - no nops: see old value on multiple pins randomly
88 * - 1 nop: only TR often shows old value
89 * - 2 nops: ?
90 */
91 nop
92 nop
93.endm
94
95
96.global test_joy_read_log /* u8 *dest, int size, int do_sync */
97test_joy_read_log:
98 ldarg 0, 0, a1
99 ldarg 1, 0, d0
100 ldarg 2, 0, d1
101 movem.l d2-d7, -(sp)
102 movea.l #0xa10003, a0
103 move.l d0, d7
104 move.l d1, d6
105
106 moveq.l #0, d0
107 move.l #0x40, d1
108 move.b d1, (6,a0)
109 move.b d1, (a0)
110
111 tst.l d6
112 beq.s 2f
113 bsr sync_with_teensy
114
1152: /* save data */
116 move.b d0, (a0)
117 t_nop
118 move.b (a0), d2
119 move.b d1, (a0)
120 t_nop
121 move.b (a0), d3
122 move.b d0, (a0)
123 t_nop
124 move.b (a0), d4
125 move.b d1, (a0)
126 t_nop
127 move.b (a0), d5
128.if 0
129 /* broken on Mega-ED v9?? */
130 move.b d2, (a1)+
131 move.b d3, (a1)+
132 move.b d4, (a1)+
133 move.b d5, (a1)+
134.else
135 lsl.w #8, d2
136 move.b d3, d2
137 move.w d2, (a1)+
138 lsl.w #8, d4
139 move.b d5, d4
140 move.w d4, (a1)+
141.endif
142
143 /* delay for teensy, 128 not enough.. */
144 move.l #256, d2
1450:
146 dbra d2, 0b
147
148 subq.l #4, d7
149 bgt.s 2b
150
151 movem.l (sp)+, d2-d7
152 rts
153
154
155.global test_joy_read_log_vsync /* u8 *dest, int size */
156test_joy_read_log_vsync:
157 ldarg 0, 0, a1
158 ldarg 1, 0, d0
159 movem.l d2-d7/a2, -(sp)
160 movea.l #0xa10003, a0
161 movea.l #0xc00005, a2
162 move.l d0, d7
163
164 move.l #0x40, d1
165 moveq.l #0, d0
166 move.b d1, (6,a0)
167 move.b d1, (a0)
168
169 bsr sync_with_teensy
170
1712: /* save data */
172 move.b d0, (a0)
173 move.b (a0), d2
174 move.b d1, (a0)
175 move.b (a0), d3
176 move.b d2, (a1)+
177 move.b d3, (a1)+
178
179 /* wait for next vsync */
180 moveq.l #3, d2
1810:
182 btst d2, (a2)
183 bne.s 0b
1840:
185 btst d2, (a2)
186 beq.s 0b
187
188 subq.l #2, d7
189 bgt.s 2b
190
191 movem.l (sp)+, d2-d7/a2
192 rts
193
194
195.global test_byte_write /* u8 *dest, int size, int seed */
196test_byte_write:
197 ldarg 0, 0, a0
198 ldarg 1, 0, d0
199 ldarg 2, 0, d1
200 movem.l d2-d7, -(sp)
201
202 move.l a0, a1
203 add.l d0, a1
204 move.l d1, d7
2050:
206 move.b d7, d0
207 addq.b #1, d7
208 move.b d7, d1
209 addq.b #1, d7
210 move.b d7, d2
211 addq.b #1, d7
212 move.b d7, d3
213 addq.b #1, d7
214 move.b d7, d4
215 addq.b #1, d7
216 move.b d7, d5
217 addq.b #1, d7
218 move.b d7, d6
219 addq.b #1, d7
220
221 move.b d0, (a0)+
222 move.b d1, (a0)+
223 move.b d2, (a0)+
224 move.b d3, (a0)+
225 move.b d4, (a0)+
226 move.b d5, (a0)+
227 move.b d6, (a0)+
228 move.b d7, (a0)+
229 addq.b #1, d7
230 cmp.l a1, a0
231 blt.s 0b
232
233 movem.l (sp)+, d2-d7
234 rts
235
236
237.global run_game /* u16 mapper, int tas_sync */
238run_game:
239 move.w #0x2700, sr
240 ldarg 0, 0, d7
241 ldarg 1, 0, d6
242 movea.l #0xa10000, a6
243 movea.l #0xc00000, a5
244 movea.l #0xc00005, a4
245 movea.l #0xc00004, a3
246 moveq.l #0x00, d0
247 move.b #0x40, d1 /* d2 is tmp */
248 move.b #0xff, d3
249 move.b d1, (0x09,a6) /* CtrlA */
250 move.b d0, (0x0b,a6) /* CtrlB */
251 move.b d0, (0x0d,a6) /* CtrlC */
252 move.b d0, (0x13,a6) /* S-CtrlA */
253 move.b d3, (0x0f,a6) /* TxDataA */
254 move.b d0, (0x19,a6) /* S-CtrlB */
255 move.b d3, (0x15,a6) /* TxDataB */
256 move.b d0, (0x1f,a6) /* S-CtrlC */
257 move.b d3, (0x1b,a6) /* TxDataC */
258
259 /* set up for vram write */
260 move.l #0x40000000, (a3)
261
262 move.l #0xff0000, a1
263 move.l #0x10000/4/4-1, d2
2640:
265 move.l d0, (a1)+
266 move.l d0, (a1)+
267 move.l d0, (a1)+
268 move.l d0, (a1)+
269 dbra d2, 0b
270
271 lea (run_game_r,pc), a0
272 move.l #0xffff80, a1
273 move.l #(run_game_r_end - run_game_r)/2-1, d2
2740:
275 move.w (a0)+, (a1)+
276 dbra d2, 0b
277
278 tst.l d6
279 beq.s 0f
280
281 movea.l #0xa10003, a0
282 movea.l d0, a7
283 bsr sync_with_teensy /* trashes d3 */
284 move.l d0, (-4,a7)
285
2860:
287 /* wait for active display */
288 moveq.l #3, d2
2890:
290 btst d2, (a4) /* 8 */
291 beq.s 0b /* 10 */
2920:
293 btst d2, (a4)
294 bne.s 0b
295
296 /* flood the VDP FIFO */
297.rept 5
298 move.w d0, (a5)
299.endr
300
301 movea.l d0, a0
302 movea.l #0xA13000, a1
303
304 move.b d0, (0x09,a6) /* CtrlA */
305 move.b d1, (0x03,a6)
306
307 jmp 0xffff80
308
309run_game_r:
310 move.w #0x3210, (0x06,a1) /* 0xA13006 */
311 move.w d7, (0x10,a1) /* 0xA13010 */
312 move.w d0, (a1) /* 0xA13000 */
313
314 move.l (a0)+, a7
315 move.l (a0), a0
316
317 jmp (a0)
318run_game_r_end:
319
320# vim:filetype=asmM68k:ts=4:sw=4:expandtab