| cc68a136 |
1 | .global code940\r |
| 2 | \r |
| 3 | code940: @ interrupt table:\r |
| 4 | b .b_reset @ reset\r |
| 5 | b .b_undef @ undefined instructions\r |
| 6 | b .b_swi @ software interrupt\r |
| 7 | b .b_pabort @ prefetch abort\r |
| 8 | b .b_dabort @ data abort\r |
| 9 | b .b_reserved @ reserved\r |
| 10 | b .b_irq @ IRQ\r |
| 11 | b .b_fiq @ FIQ\r |
| 12 | \r |
| 13 | @ test\r |
| 14 | .b_reset:\r |
| 15 | mov r12, #0\r |
| 16 | b .Begin\r |
| 17 | .b_undef:\r |
| 18 | mov r12, #1\r |
| 19 | b .Begin\r |
| 20 | .b_swi:\r |
| 21 | mov r12, #2\r |
| 22 | b .Begin\r |
| 23 | .b_pabort:\r |
| 24 | mov r12, #3\r |
| 25 | b .Begin\r |
| 26 | .b_dabort:\r |
| 27 | mov r12, #4\r |
| 28 | b .Begin\r |
| 29 | .b_reserved:\r |
| 30 | mov r12, #5\r |
| 31 | b .Begin\r |
| 32 | .b_irq:\r |
| 33 | mov r12, #6\r |
| b837b69b |
34 | mov sp, #0x100000 @ reset stack\r |
| 35 | sub sp, sp, #4\r |
| 36 | mov r1, #0xbe000000 @ assume we live @ 0x2000000 bank\r |
| cc68a136 |
37 | orr r2, r1, #0x3B00\r |
| 38 | orr r2, r2, #0x0046\r |
| 39 | mvn r3, #0\r |
| 40 | strh r3, [r2] @ clear any pending interrupts from the DUALCPU unit\r |
| 41 | orr r2, r1, #0x4500\r |
| 42 | str r3, [r2] @ clear all pending interrupts in irq controller's SRCPND register\r |
| 43 | orr r2, r2, #0x0010\r |
| 44 | str r3, [r2] @ clear all pending interrupts in irq controller's INTPND register\r |
| 45 | b .Enter\r |
| 46 | .b_fiq:\r |
| 47 | mov r12, #7\r |
| 48 | b .Begin\r |
| 49 | \r |
| 50 | .Begin:\r |
| b837b69b |
51 | mov sp, #0x100000 @ set the stack top (1M)\r |
| 52 | sub sp, sp, #4 @ minus 4\r |
| cc68a136 |
53 | \r |
| b837b69b |
54 | @ set up memory region 0 -- the whole 4GB address space\r |
| 55 | mov r0, #(0x1f<<1)|1 @ region data\r |
| 56 | mcr p15, 0, r0, c6, c0, 0 @ opcode2 ~ data/instr\r |
| 57 | mcr p15, 0, r0, c6, c0, 1\r |
| cc68a136 |
58 | \r |
| 59 | @ set up region 1 which is the first 2 megabytes.\r |
| b837b69b |
60 | mov r0, #(0x14<<1)|1 @ region data\r |
| 61 | mcr p15, 0, r0, c6, c1, 0\r |
| 62 | mcr p15, 0, r0, c6, c1, 1\r |
| cc68a136 |
63 | \r |
| 64 | @ set up region 2: 64k 0x200000-0x210000\r |
| b837b69b |
65 | mov r0, #(0x0f<<1)|1\r |
| cc68a136 |
66 | orr r0, r0, #0x200000\r |
| b837b69b |
67 | mcr p15, 0, r0, c6, c2, 0\r |
| 68 | mcr p15, 0, r0, c6, c2, 1\r |
| cc68a136 |
69 | \r |
| b837b69b |
70 | @ set up region 3: 64k 0xbe000000-0xbe010000 (hw control registers)\r |
| 71 | mov r0, #(0x0f<<1)|1\r |
| 72 | orr r0, r0, #0xbe000000\r |
| 73 | mcr p15, 0, r0, c6, c3, 0\r |
| 74 | mcr p15, 0, r0, c6, c3, 1\r |
| cc68a136 |
75 | \r |
| 42c7b147 |
76 | @ set up region 4: 16M 0x01000000-0x02000000 (mp3 area)\r |
| 77 | mov r0, #(0x17<<1)|1\r |
| 78 | orr r0, r0, #0x01000000\r |
| 79 | mcr p15, 0, r0, c6, c4, 0\r |
| 80 | mcr p15, 0, r0, c6, c4, 1\r |
| 81 | \r |
| 82 | @ set regions 1 and 4 to be cacheable (so the first 2M and mp3 area will be cacheable)\r |
| 83 | mov r0, #(1<<1)|(1<<4)\r |
| b837b69b |
84 | mcr p15, 0, r0, c2, c0, 0\r |
| 85 | mcr p15, 0, r0, c2, c0, 1\r |
| cc68a136 |
86 | \r |
| 87 | @ set region 1 to be bufferable too (only data)\r |
| 42c7b147 |
88 | mov r0, #(1<<1)\r |
| b837b69b |
89 | mcr p15, 0, r0, c3, c0, 0\r |
| cc68a136 |
90 | \r |
| 91 | @ set protection, allow accsess only to regions 1 and 2\r |
| 42c7b147 |
92 | 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 |
93 | mcr p15, 0, r0, c5, c0, 0\r |
| 42c7b147 |
94 | mov r0, #(0<<8)|(0<<6)|(0<<4)|(3<<2)|(0) @ instructions: [no access, no, no, full, no]\r |
| b837b69b |
95 | mcr p15, 0, r0, c5, c0, 1\r |
| 96 | \r |
| 97 | mrc p15, 0, r0, c1, c0, 0 @ fetch current control reg\r |
| 98 | orr r0, r0, #1 @ 0x00000001: enable protection unit\r |
| 99 | orr r0, r0, #4 @ 0x00000004: enable D cache\r |
| 100 | orr r0, r0, #0x1000 @ 0x00001000: enable I cache\r |
| 42c7b147 |
101 | bic r0, r0, #0xC0000000\r |
| 102 | orr r0, r0, #0x40000000 @ 0x40000000: synchronous, faster?\r |
| 103 | @ orr r0, r0, #0xC0000000 @ 0xC0000000: async\r |
| b837b69b |
104 | mcr p15, 0, r0, c1, c0, 0 @ set control reg\r |
| cc68a136 |
105 | \r |
| 106 | @ flush (invalidate) the cache (just in case)\r |
| 107 | mov r0, #0\r |
| 108 | mcr p15, 0, r0, c7, c6, 0\r |
| 109 | \r |
| 110 | .Enter:\r |
| 111 | mov r0, r12\r |
| 112 | bl Main940\r |
| 113 | \r |
| 114 | @ we should never get here\r |
| 115 | .b_deadloop:\r |
| 116 | b .b_deadloop\r |
| 117 | \r |
| 118 | \r |
| 119 | \r |
| 120 | @ so asm utils are also defined here:\r |
| 121 | .global spend_cycles @ c\r |
| 122 | \r |
| 123 | spend_cycles:\r |
| 124 | mov r0, r0, lsr #2 @ 4 cycles/iteration\r |
| 125 | sub r0, r0, #2 @ entry/exit/init\r |
| 126 | .sc_loop:\r |
| 127 | subs r0, r0, #1\r |
| 128 | bpl .sc_loop\r |
| 129 | \r |
| 130 | bx lr\r |
| 131 | \r |
| 132 | \r |
| 133 | @ clean-flush function from ARM940T technical reference manual\r |
| 134 | .global cache_clean_flush\r |
| 135 | \r |
| 136 | cache_clean_flush:\r |
| 137 | mov r1, #0 @ init line counter\r |
| 138 | ccf_outer_loop:\r |
| 139 | mov r0, #0 @ segment counter\r |
| 140 | ccf_inner_loop:\r |
| 141 | orr r2, r1, r0 @ make segment and line address\r |
| 142 | mcr p15, 0, r2, c7, c14, 2 @ clean and flush that line\r |
| 143 | add r0, r0, #0x10 @ incremet secment counter\r |
| 144 | cmp r0, #0x40 @ complete all 4 segments?\r |
| 145 | bne ccf_inner_loop\r |
| 146 | add r1, r1, #0x04000000 @ increment line counter\r |
| 147 | cmp r1, #0 @ complete all lines?\r |
| 148 | bne ccf_outer_loop\r |
| 149 | bx lr\r |
| 150 | \r |
| 151 | \r |
| 152 | @ clean-only version\r |
| 153 | .global cache_clean\r |
| 154 | \r |
| 155 | cache_clean:\r |
| 156 | mov r1, #0 @ init line counter\r |
| 157 | cf_outer_loop:\r |
| 158 | mov r0, #0 @ segment counter\r |
| 159 | cf_inner_loop:\r |
| 160 | orr r2, r1, r0 @ make segment and line address\r |
| 161 | mcr p15, 0, r2, c7, c10, 2 @ clean that line\r |
| 162 | add r0, r0, #0x10 @ incremet secment counter\r |
| 163 | cmp r0, #0x40 @ complete all 4 segments?\r |
| 164 | bne cf_inner_loop\r |
| 165 | add r1, r1, #0x04000000 @ increment line counter\r |
| 166 | cmp r1, #0 @ complete all lines?\r |
| 167 | bne cf_outer_loop\r |
| 168 | bx lr\r |
| 169 | \r |
| 170 | \r |
| 171 | .global wait_irq\r |
| 172 | \r |
| 173 | wait_irq:\r |
| 174 | mrs r0, cpsr\r |
| 175 | bic r0, r0, #0x80\r |
| 176 | msr cpsr_c, r0 @ enable interrupts\r |
| 177 | \r |
| 178 | mov r0, #0\r |
| 179 | mcr p15, 0, r0, c7, c0, 4 @ wait for IRQ\r |
| 180 | @ mcr p15, 0, r0, c15, c8, 2\r |
| 181 | b .b_reserved\r |
| 182 | \r |
| 183 | .pool\r |
| b837b69b |
184 | \r |
| 51a902ae |
185 | \r |
| 186 | .global set_if_not_changed @ int *val, int oldval, int newval\r |
| 187 | \r |
| 188 | set_if_not_changed:\r |
| 189 | swp r3, r2, [r0]\r |
| 190 | cmp r1, r3\r |
| 191 | bxeq lr\r |
| 192 | strne r3, [r0] @ restore value which was changed there by other core\r |
| 193 | bx lr\r |
| 194 | \r |
| 42c7b147 |
195 | @ vim:filetype=armasm:\r |
notaz.gp2x.de / picodrive.git / blame