paul@68 | 1 | /* |
paul@68 | 2 | * Handler routines. |
paul@68 | 3 | * |
paul@68 | 4 | * Copyright (C) 2008 by Maurus Cuelenaere |
paul@68 | 5 | * Copyright (C) 2015 Paul Boddie <paul@boddie.org.uk> |
paul@68 | 6 | * |
paul@68 | 7 | * This program is free software: you can redistribute it and/or modify |
paul@68 | 8 | * it under the terms of the GNU General Public License as published by |
paul@68 | 9 | * the Free Software Foundation, either version 3 of the License, or |
paul@68 | 10 | * (at your option) any later version. |
paul@68 | 11 | * |
paul@68 | 12 | * This program is distributed in the hope that it will be useful, |
paul@68 | 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
paul@68 | 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
paul@68 | 15 | * GNU General Public License for more details. |
paul@68 | 16 | * |
paul@68 | 17 | * You should have received a copy of the GNU General Public License |
paul@68 | 18 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
paul@68 | 19 | */ |
paul@68 | 20 | |
paul@68 | 21 | .text |
paul@68 | 22 | .extern irq_handle |
paul@71 | 23 | .extern irq_counter |
paul@79 | 24 | .globl _exc_stack |
paul@68 | 25 | .globl real_exception_handler |
paul@68 | 26 | .set noreorder |
paul@68 | 27 | .set noat |
paul@68 | 28 | |
paul@79 | 29 | #define C0_STATUS $12 |
paul@79 | 30 | #define C0_CAUSE $13 |
paul@79 | 31 | #define C0_EPC $14 |
paul@79 | 32 | #define C0_CONFIG $16 |
paul@79 | 33 | #define C0_ERROREPC $30 |
paul@79 | 34 | #define S_CauseExcCode 2 |
paul@79 | 35 | #define M_CauseExcCode (0x1f << S_CauseExcCode) |
paul@79 | 36 | |
paul@79 | 37 | _exc_stack: |
paul@79 | 38 | .word 0 |
paul@68 | 39 | |
paul@68 | 40 | real_exception_handler: |
paul@79 | 41 | addiu $sp, -0x88 /* multiple of 8 */ |
paul@68 | 42 | sw $ra, 0($sp) |
paul@68 | 43 | sw $fp, 4($sp) |
paul@68 | 44 | sw $gp, 8($sp) |
paul@68 | 45 | sw $t9, 0xC($sp) |
paul@68 | 46 | sw $t8, 0x10($sp) |
paul@68 | 47 | sw $s7, 0x14($sp) |
paul@68 | 48 | sw $s6, 0x18($sp) |
paul@68 | 49 | sw $s5, 0x1C($sp) |
paul@68 | 50 | sw $s4, 0x20($sp) |
paul@68 | 51 | sw $s3, 0x24($sp) |
paul@68 | 52 | sw $s2, 0x28($sp) |
paul@68 | 53 | sw $s1, 0x2C($sp) |
paul@68 | 54 | sw $s0, 0x30($sp) |
paul@68 | 55 | sw $t7, 0x34($sp) |
paul@68 | 56 | sw $t6, 0x38($sp) |
paul@68 | 57 | sw $t5, 0x3C($sp) |
paul@68 | 58 | sw $t4, 0x40($sp) |
paul@68 | 59 | sw $t3, 0x44($sp) |
paul@68 | 60 | sw $t2, 0x48($sp) |
paul@68 | 61 | sw $t1, 0x4C($sp) |
paul@68 | 62 | sw $t0, 0x50($sp) |
paul@68 | 63 | sw $a3, 0x54($sp) |
paul@68 | 64 | sw $a2, 0x58($sp) |
paul@68 | 65 | sw $a1, 0x5C($sp) |
paul@68 | 66 | sw $a0, 0x60($sp) |
paul@68 | 67 | sw $v1, 0x64($sp) |
paul@68 | 68 | sw $v0, 0x68($sp) |
paul@68 | 69 | sw $1, 0x6C($sp) |
paul@68 | 70 | mflo $k0 |
paul@68 | 71 | nop |
paul@68 | 72 | sw $k0, 0x70($sp) |
paul@68 | 73 | mfhi $k0 |
paul@68 | 74 | nop |
paul@68 | 75 | sw $k0, 0x74($sp) |
paul@68 | 76 | mfc0 $k0, C0_STATUS |
paul@68 | 77 | sll $zero, 1 |
paul@68 | 78 | sll $zero, 1 |
paul@68 | 79 | sll $zero, 1 |
paul@68 | 80 | sll $zero, 1 |
paul@68 | 81 | sw $k0, 0x78($sp) |
paul@68 | 82 | mfc0 $k0, C0_EPC |
paul@68 | 83 | sll $zero, 1 |
paul@68 | 84 | sll $zero, 1 |
paul@68 | 85 | sll $zero, 1 |
paul@68 | 86 | sll $zero, 1 |
paul@68 | 87 | sw $k0, 0x7C($sp) |
paul@71 | 88 | mfc0 $k0, C0_ERROREPC |
paul@71 | 89 | sll $zero, 1 |
paul@71 | 90 | sll $zero, 1 |
paul@71 | 91 | sll $zero, 1 |
paul@71 | 92 | sll $zero, 1 |
paul@71 | 93 | sw $k0, 0x80($sp) |
paul@68 | 94 | |
paul@68 | 95 | li $k1, M_CauseExcCode |
paul@68 | 96 | mfc0 $k0, C0_CAUSE |
paul@68 | 97 | and $k0, $k1 |
paul@68 | 98 | beq $zero, $k0, _int |
paul@68 | 99 | nop |
paul@68 | 100 | j _exception |
paul@68 | 101 | nop |
paul@68 | 102 | |
paul@68 | 103 | _int: |
paul@79 | 104 | /* Initialise the kernel stack. */ |
paul@79 | 105 | |
paul@79 | 106 | la $k1, _exc_stack |
paul@79 | 107 | lw $k0, 0($k1) |
paul@79 | 108 | sw $sp, 0($k0) |
paul@79 | 109 | addiu $k0, -4 |
paul@79 | 110 | move $sp, $k0 |
paul@79 | 111 | |
paul@71 | 112 | /* Initialise the globals pointer. */ |
paul@71 | 113 | |
paul@71 | 114 | lui $gp, %hi(_GLOBAL_OFFSET_TABLE_) |
paul@71 | 115 | ori $gp, $gp, %lo(_GLOBAL_OFFSET_TABLE_) |
paul@71 | 116 | |
paul@71 | 117 | /* Test with counter. */ |
paul@71 | 118 | |
paul@71 | 119 | la $t0, irq_counter |
paul@71 | 120 | lw $t1, 0($t0) |
paul@71 | 121 | addiu $t1, $t1, 1 |
paul@71 | 122 | sw $t1, 0($t0) |
paul@71 | 123 | |
paul@68 | 124 | /* Invoke the handler. */ |
paul@68 | 125 | |
paul@68 | 126 | jal irq_handle |
paul@68 | 127 | nop |
paul@79 | 128 | |
paul@79 | 129 | /* Restore the user stack. */ |
paul@79 | 130 | |
paul@79 | 131 | addiu $sp, 4 |
paul@79 | 132 | lw $sp, 0($sp) |
paul@79 | 133 | |
paul@68 | 134 | j _exception_return |
paul@69 | 135 | nop |
paul@68 | 136 | |
paul@68 | 137 | _exception: |
paul@68 | 138 | j _exception_return |
paul@68 | 139 | nop |
paul@68 | 140 | |
paul@68 | 141 | _exception_return: |
paul@68 | 142 | lw $ra, 0($sp) |
paul@68 | 143 | lw $fp, 4($sp) |
paul@68 | 144 | lw $gp, 8($sp) |
paul@68 | 145 | lw $t9, 0xC($sp) |
paul@68 | 146 | lw $t8, 0x10($sp) |
paul@68 | 147 | lw $s7, 0x14($sp) |
paul@68 | 148 | lw $s6, 0x18($sp) |
paul@68 | 149 | lw $s5, 0x1C($sp) |
paul@68 | 150 | lw $s4, 0x20($sp) |
paul@68 | 151 | lw $s3, 0x24($sp) |
paul@68 | 152 | lw $s2, 0x28($sp) |
paul@68 | 153 | lw $s1, 0x2C($sp) |
paul@68 | 154 | lw $s0, 0x30($sp) |
paul@68 | 155 | lw $t7, 0x34($sp) |
paul@68 | 156 | lw $t6, 0x38($sp) |
paul@68 | 157 | lw $t5, 0x3C($sp) |
paul@68 | 158 | lw $t4, 0x40($sp) |
paul@68 | 159 | lw $t3, 0x44($sp) |
paul@68 | 160 | lw $t2, 0x48($sp) |
paul@68 | 161 | lw $t1, 0x4C($sp) |
paul@68 | 162 | lw $t0, 0x50($sp) |
paul@68 | 163 | lw $a3, 0x54($sp) |
paul@68 | 164 | lw $a2, 0x58($sp) |
paul@68 | 165 | lw $a1, 0x5C($sp) |
paul@68 | 166 | lw $a0, 0x60($sp) |
paul@68 | 167 | lw $v1, 0x64($sp) |
paul@68 | 168 | lw $v0, 0x68($sp) |
paul@68 | 169 | lw $1, 0x6C($sp) |
paul@68 | 170 | lw $k0, 0x70($sp) |
paul@68 | 171 | mtlo $k0 |
paul@68 | 172 | nop |
paul@68 | 173 | lw $k0, 0x74($sp) |
paul@68 | 174 | mthi $k0 |
paul@68 | 175 | nop |
paul@68 | 176 | lw $k0, 0x78($sp) |
paul@68 | 177 | mtc0 $k0, C0_STATUS |
paul@68 | 178 | nop |
paul@68 | 179 | sll $zero, 1 |
paul@68 | 180 | sll $zero, 1 |
paul@68 | 181 | sll $zero, 1 |
paul@68 | 182 | sll $zero, 1 |
paul@68 | 183 | lw $k0, 0x7C($sp) |
paul@68 | 184 | mtc0 $k0, C0_EPC |
paul@68 | 185 | nop |
paul@68 | 186 | sll $zero, 1 |
paul@68 | 187 | sll $zero, 1 |
paul@68 | 188 | sll $zero, 1 |
paul@68 | 189 | sll $zero, 1 |
paul@71 | 190 | lw $k0, 0x80($sp) |
paul@71 | 191 | mtc0 $k0, C0_ERROREPC |
paul@71 | 192 | nop |
paul@71 | 193 | sll $zero, 1 |
paul@71 | 194 | sll $zero, 1 |
paul@71 | 195 | sll $zero, 1 |
paul@71 | 196 | sll $zero, 1 |
paul@79 | 197 | addiu $sp, 0x88 /* multiple of 8 */ |
paul@68 | 198 | eret |
paul@68 | 199 | nop |
paul@68 | 200 | |
paul@68 | 201 | .set reorder |
paul@68 | 202 | .set at |