cc68a136 |
1 | .global code940\r |
2 | \r |
4f265db7 |
3 | .equ mmsp2_regs, (0xc0000000-0x02000000) @ assume we live @ 0x2000000 bank\r |
4 | \r |
cc68a136 |
5 | code940: @ interrupt table:\r |
6 | b .b_reset @ reset\r |
7 | b .b_undef @ undefined instructions\r |
8 | b .b_swi @ software interrupt\r |
9 | b .b_pabort @ prefetch abort\r |
10 | b .b_dabort @ data abort\r |
11 | b .b_reserved @ reserved\r |
12 | b .b_irq @ IRQ\r |
13 | b .b_fiq @ FIQ\r |
14 | \r |
15 | @ test\r |
16 | .b_reset:\r |
17 | mov r12, #0\r |
18 | b .Begin\r |
19 | .b_undef:\r |
20 | mov r12, #1\r |
21 | b .Begin\r |
22 | .b_swi:\r |
23 | mov r12, #2\r |
24 | b .Begin\r |
25 | .b_pabort:\r |
26 | mov r12, #3\r |
27 | b .Begin\r |
28 | .b_dabort:\r |
29 | mov r12, #4\r |
30 | b .Begin\r |
31 | .b_reserved:\r |
32 | mov r12, #5\r |
33 | b .Begin\r |
34 | .b_irq:\r |
35 | mov r12, #6\r |
b837b69b |
36 | mov sp, #0x100000 @ reset stack\r |
37 | sub sp, sp, #4\r |
4f265db7 |
38 | mov r1, #mmsp2_regs\r |
cc68a136 |
39 | orr r2, r1, #0x3B00\r |
40 | orr r2, r2, #0x0046\r |
41 | mvn r3, #0\r |
42 | strh r3, [r2] @ clear any pending interrupts from the DUALCPU unit\r |
43 | orr r2, r1, #0x4500\r |
44 | str r3, [r2] @ clear all pending interrupts in irq controller's SRCPND register\r |
45 | orr r2, r2, #0x0010\r |
46 | str r3, [r2] @ clear all pending interrupts in irq controller's INTPND register\r |
47 | b .Enter\r |
48 | .b_fiq:\r |
49 | mov r12, #7\r |
50 | b .Begin\r |
51 | \r |
52 | .Begin:\r |
b837b69b |
53 | mov sp, #0x100000 @ set the stack top (1M)\r |
54 | sub sp, sp, #4 @ minus 4\r |
cc68a136 |
55 | \r |
b837b69b |
56 | @ set up memory region 0 -- the whole 4GB address space\r |
57 | mov r0, #(0x1f<<1)|1 @ region data\r |
58 | mcr p15, 0, r0, c6, c0, 0 @ opcode2 ~ data/instr\r |
59 | mcr p15, 0, r0, c6, c0, 1\r |
cc68a136 |
60 | \r |
61 | @ set up region 1 which is the first 2 megabytes.\r |
b837b69b |
62 | mov r0, #(0x14<<1)|1 @ region data\r |
63 | mcr p15, 0, r0, c6, c1, 0\r |
64 | mcr p15, 0, r0, c6, c1, 1\r |
cc68a136 |
65 | \r |
66 | @ set up region 2: 64k 0x200000-0x210000\r |
b837b69b |
67 | mov r0, #(0x0f<<1)|1\r |
cc68a136 |
68 | orr r0, r0, #0x200000\r |
b837b69b |
69 | mcr p15, 0, r0, c6, c2, 0\r |
70 | mcr p15, 0, r0, c6, c2, 1\r |
cc68a136 |
71 | \r |
b837b69b |
72 | @ set up region 3: 64k 0xbe000000-0xbe010000 (hw control registers)\r |
73 | mov r0, #(0x0f<<1)|1\r |
4f265db7 |
74 | orr r0, r0, #mmsp2_regs\r |
b837b69b |
75 | mcr p15, 0, r0, c6, c3, 0\r |
76 | mcr p15, 0, r0, c6, c3, 1\r |
cc68a136 |
77 | \r |
42c7b147 |
78 | @ set up region 4: 16M 0x01000000-0x02000000 (mp3 area)\r |
79 | mov r0, #(0x17<<1)|1\r |
80 | orr r0, r0, #0x01000000\r |
81 | mcr p15, 0, r0, c6, c4, 0\r |
82 | mcr p15, 0, r0, c6, c4, 1\r |
83 | \r |
84 | @ set regions 1 and 4 to be cacheable (so the first 2M and mp3 area will be cacheable)\r |
85 | mov r0, #(1<<1)|(1<<4)\r |
b837b69b |
86 | mcr p15, 0, r0, c2, c0, 0\r |
87 | mcr p15, 0, r0, c2, c0, 1\r |
cc68a136 |
88 | \r |
89 | @ set region 1 to be bufferable too (only data)\r |
42c7b147 |
90 | mov r0, #(1<<1)\r |
b837b69b |
91 | mcr p15, 0, r0, c3, c0, 0\r |
cc68a136 |
92 | \r |
4f265db7 |
93 | @ set protection, allow access only to regions 1 and 2\r |
42c7b147 |
94 | mov r0, #(3<<8)|(3<<6)|(3<<4)|(3<<2)|(0) @ data: [full, full, full, full, no access] for regions [4 3 2 1 0]\r |
b837b69b |
95 | mcr p15, 0, r0, c5, c0, 0\r |
42c7b147 |
96 | mov r0, #(0<<8)|(0<<6)|(0<<4)|(3<<2)|(0) @ instructions: [no access, no, no, full, no]\r |
b837b69b |
97 | mcr p15, 0, r0, c5, c0, 1\r |
98 | \r |
99 | mrc p15, 0, r0, c1, c0, 0 @ fetch current control reg\r |
100 | orr r0, r0, #1 @ 0x00000001: enable protection unit\r |
101 | orr r0, r0, #4 @ 0x00000004: enable D cache\r |
102 | orr r0, r0, #0x1000 @ 0x00001000: enable I cache\r |
4f265db7 |
103 | @ bic r0, r0, #0xC0000000\r |
104 | @ orr r0, r0, #0x40000000 @ 0x40000000: synchronous, faster?\r |
105 | orr r0, r0, #0xC0000000 @ 0xC0000000: async\r |
b837b69b |
106 | mcr p15, 0, r0, c1, c0, 0 @ set control reg\r |
cc68a136 |
107 | \r |
108 | @ flush (invalidate) the cache (just in case)\r |
109 | mov r0, #0\r |
110 | mcr p15, 0, r0, c7, c6, 0\r |
111 | \r |
112 | .Enter:\r |
113 | mov r0, r12\r |
4f265db7 |
114 | mov r1, lr\r |
cc68a136 |
115 | bl Main940\r |
116 | \r |
117 | @ we should never get here\r |
4f265db7 |
118 | @.b_deadloop:\r |
119 | @ b .b_deadloop\r |
120 | b .b_reserved\r |
cc68a136 |
121 | \r |
122 | \r |
123 | \r |
124 | @ so asm utils are also defined here:\r |
125 | .global spend_cycles @ c\r |
126 | \r |
127 | spend_cycles:\r |
128 | mov r0, r0, lsr #2 @ 4 cycles/iteration\r |
129 | sub r0, r0, #2 @ entry/exit/init\r |
130 | .sc_loop:\r |
131 | subs r0, r0, #1\r |
132 | bpl .sc_loop\r |
133 | \r |
134 | bx lr\r |
135 | \r |
136 | \r |
137 | @ clean-flush function from ARM940T technical reference manual\r |
138 | .global cache_clean_flush\r |
139 | \r |
140 | cache_clean_flush:\r |
141 | mov r1, #0 @ init line counter\r |
142 | ccf_outer_loop:\r |
143 | mov r0, #0 @ segment counter\r |
144 | ccf_inner_loop:\r |
145 | orr r2, r1, r0 @ make segment and line address\r |
146 | mcr p15, 0, r2, c7, c14, 2 @ clean and flush that line\r |
147 | add r0, r0, #0x10 @ incremet secment counter\r |
148 | cmp r0, #0x40 @ complete all 4 segments?\r |
149 | bne ccf_inner_loop\r |
150 | add r1, r1, #0x04000000 @ increment line counter\r |
151 | cmp r1, #0 @ complete all lines?\r |
152 | bne ccf_outer_loop\r |
153 | bx lr\r |
154 | \r |
155 | \r |
156 | @ clean-only version\r |
157 | .global cache_clean\r |
158 | \r |
159 | cache_clean:\r |
160 | mov r1, #0 @ init line counter\r |
161 | cf_outer_loop:\r |
162 | mov r0, #0 @ segment counter\r |
163 | cf_inner_loop:\r |
164 | orr r2, r1, r0 @ make segment and line address\r |
165 | mcr p15, 0, r2, c7, c10, 2 @ clean that line\r |
166 | add r0, r0, #0x10 @ incremet secment counter\r |
167 | cmp r0, #0x40 @ complete all 4 segments?\r |
168 | bne cf_inner_loop\r |
169 | add r1, r1, #0x04000000 @ increment line counter\r |
170 | cmp r1, #0 @ complete all lines?\r |
171 | bne cf_outer_loop\r |
172 | bx lr\r |
173 | \r |
174 | \r |
175 | .global wait_irq\r |
176 | \r |
177 | wait_irq:\r |
4f265db7 |
178 | mov r0, #mmsp2_regs\r |
179 | orr r0, r0, #0x3B00\r |
180 | orr r1, r0, #0x0042\r |
181 | mov r3, #0\r |
182 | strh r3, [r1] @ disable interrupts\r |
183 | orr r2, r0, #0x003E\r |
184 | strh r3, [r2] @ remove busy flag\r |
185 | mov r3, #1\r |
186 | strh r3, [r1] @ enable interrupts\r |
187 | \r |
cc68a136 |
188 | mrs r0, cpsr\r |
189 | bic r0, r0, #0x80\r |
4f265db7 |
190 | msr cpsr_c, r0 @ enable interrupts\r |
cc68a136 |
191 | \r |
192 | mov r0, #0\r |
193 | mcr p15, 0, r0, c7, c0, 4 @ wait for IRQ\r |
194 | @ mcr p15, 0, r0, c15, c8, 2\r |
4f265db7 |
195 | nop\r |
196 | nop\r |
cc68a136 |
197 | b .b_reserved\r |
198 | \r |
199 | .pool\r |
b837b69b |
200 | \r |
51a902ae |
201 | \r |
202 | .global set_if_not_changed @ int *val, int oldval, int newval\r |
203 | \r |
204 | set_if_not_changed:\r |
205 | swp r3, r2, [r0]\r |
206 | cmp r1, r3\r |
207 | bxeq lr\r |
208 | strne r3, [r0] @ restore value which was changed there by other core\r |
209 | bx lr\r |
210 | \r |
42c7b147 |
211 | @ vim:filetype=armasm:\r |