cff531af |
1 | /* |
2 | * PicoDrive |
3 | * (C) notaz, 2009 |
4 | * |
5 | * This work is licensed under the terms of MAME license. |
6 | * See COPYING file in the top-level directory. |
7 | */ |
5e89f0f5 |
8 | |
9 | .equ M68K_MEM_SHIFT, 16 |
10 | |
11 | .global cyclone_checkpc |
12 | .global cyclone_fetch8 |
13 | .global cyclone_fetch16 |
14 | .global cyclone_fetch32 |
15 | .global cyclone_read8 |
16 | .global cyclone_read16 |
17 | .global cyclone_read32 |
18 | .global cyclone_write8 |
19 | .global cyclone_write16 |
20 | .global cyclone_write32 |
21 | |
22 | @ Warning: here we abuse the fact that we are only called |
23 | @ from Cyclone, and assume that r7 contains context pointer. |
24 | cyclone_checkpc: |
25 | ldr r1, [r7, #0x60] @ membase |
26 | sub r0, r0, r1 |
27 | bic r0, r0, #0xff000000 |
28 | bics r0, r0, #1 |
29 | beq crashed |
30 | |
31 | ldr r1, [r7, #0x6c] @ read16 map |
32 | mov r2, r0, lsr #M68K_MEM_SHIFT |
33 | ldr r1, [r1, r2, lsl #2] |
34 | movs r1, r1, lsl #1 |
35 | bcs crashed |
36 | |
37 | str r1, [r7, #0x60] @ membase |
38 | add r0, r0, r1 |
39 | bx lr |
40 | |
41 | crashed: |
42 | stmfd sp!,{lr} |
43 | mov r1, r7 |
44 | bl cyclone_crashed |
45 | ldr r0, [r7, #0x40] @ reload PC + membase |
46 | ldmfd sp!,{pc} |
47 | |
48 | |
49 | cyclone_read8: @ u32 a |
50 | cyclone_fetch8: |
51 | bic r0, r0, #0xff000000 |
52 | ldr r1, [r7, #0x68] @ read8 map |
53 | mov r2, r0, lsr #M68K_MEM_SHIFT |
54 | ldr r1, [r1, r2, lsl #2] |
55 | eor r2, r0, #1 |
56 | movs r1, r1, lsl #1 |
57 | ldrccb r0, [r1, r2] |
58 | bxcc lr |
59 | bx r1 |
60 | |
61 | |
62 | cyclone_read16: @ u32 a |
63 | cyclone_fetch16: |
64 | bic r0, r0, #0xff000000 |
65 | ldr r1, [r7, #0x6c] @ read16 map |
66 | mov r2, r0, lsr #M68K_MEM_SHIFT |
67 | ldr r1, [r1, r2, lsl #2] |
68 | bic r0, r0, #1 |
69 | movs r1, r1, lsl #1 |
70 | ldrcch r0, [r1, r0] |
71 | bxcc lr |
72 | bx r1 |
73 | |
74 | |
75 | cyclone_read32: @ u32 a |
76 | cyclone_fetch32: |
77 | bic r0, r0, #0xff000000 |
78 | ldr r1, [r7, #0x6c] @ read16 map |
79 | mov r2, r0, lsr #M68K_MEM_SHIFT |
80 | ldr r1, [r1, r2, lsl #2] |
81 | bic r0, r0, #1 |
82 | movs r1, r1, lsl #1 |
83 | ldrcch r0, [r1, r0]! |
84 | ldrcch r1, [r1, #2] |
85 | orrcc r0, r1, r0, lsl #16 |
86 | bxcc lr |
87 | |
88 | stmfd sp!,{r0,r1,lr} |
89 | mov lr, pc |
90 | bx r1 |
91 | mov r2, r0, lsl #16 |
92 | ldmia sp, {r0,r1} |
93 | str r2, [sp] |
94 | add r0, r0, #2 |
95 | mov lr, pc |
96 | bx r1 |
97 | ldr r1, [sp] |
98 | mov r0, r0, lsl #16 |
99 | orr r0, r1, r0, lsr #16 |
100 | ldmfd sp!,{r1,r2,pc} |
101 | |
102 | |
103 | cyclone_write8: @ u32 a, u8 d |
104 | bic r0, r0, #0xff000000 |
105 | ldr r2, [r7, #0x74] @ write8 map |
106 | mov r3, r0, lsr #M68K_MEM_SHIFT |
107 | ldr r2, [r2, r3, lsl #2] |
108 | eor r3, r0, #1 |
109 | movs r2, r2, lsl #1 |
110 | strccb r1, [r2, r3] |
111 | bxcc lr |
112 | bx r2 |
113 | |
114 | |
115 | cyclone_write16: @ u32 a, u16 d |
116 | bic r0, r0, #0xff000000 |
117 | ldr r2, [r7, #0x78] @ write16 map |
118 | mov r3, r0, lsr #M68K_MEM_SHIFT |
119 | ldr r2, [r2, r3, lsl #2] |
120 | bic r0, r0, #1 |
121 | movs r2, r2, lsl #1 |
122 | strcch r1, [r2, r0] |
123 | bxcc lr |
124 | bx r2 |
125 | |
126 | |
127 | cyclone_write32: @ u32 a, u32 d |
128 | bic r0, r0, #0xff000000 |
129 | ldr r2, [r7, #0x78] @ write16 map |
130 | mov r3, r0, lsr #M68K_MEM_SHIFT |
131 | ldr r2, [r2, r3, lsl #2] |
132 | bic r0, r0, #1 |
133 | movs r2, r2, lsl #1 |
134 | movcc r3, r1, lsr #16 |
135 | strcch r3, [r2, r0]! |
136 | strcch r1, [r2, #2] |
137 | bxcc lr |
138 | |
139 | stmfd sp!,{r0-r2,lr} |
140 | mov r1, r1, lsr #16 |
141 | mov lr, pc |
142 | bx r2 |
143 | ldmfd sp!,{r0-r2,lr} |
144 | add r0, r0, #2 |
145 | bx r2 |
146 | |
cff531af |
147 | @ vim:filetype=armasm |