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@68 | 23 | .globl real_exception_handler |
paul@68 | 24 | .set noreorder |
paul@68 | 25 | .set noat |
paul@68 | 26 | |
paul@68 | 27 | #define C0_STATUS $12 |
paul@68 | 28 | #define C0_CAUSE $13 |
paul@68 | 29 | #define C0_EPC $14 |
paul@68 | 30 | #define C0_CONFIG $16 |
paul@68 | 31 | #define S_CauseExcCode 2 |
paul@68 | 32 | #define M_CauseExcCode (0x1f << S_CauseExcCode) |
paul@68 | 33 | |
paul@68 | 34 | real_exception_handler: |
paul@68 | 35 | addiu $sp, -0x80 |
paul@68 | 36 | sw $ra, 0($sp) |
paul@68 | 37 | sw $fp, 4($sp) |
paul@68 | 38 | sw $gp, 8($sp) |
paul@68 | 39 | sw $t9, 0xC($sp) |
paul@68 | 40 | sw $t8, 0x10($sp) |
paul@68 | 41 | sw $s7, 0x14($sp) |
paul@68 | 42 | sw $s6, 0x18($sp) |
paul@68 | 43 | sw $s5, 0x1C($sp) |
paul@68 | 44 | sw $s4, 0x20($sp) |
paul@68 | 45 | sw $s3, 0x24($sp) |
paul@68 | 46 | sw $s2, 0x28($sp) |
paul@68 | 47 | sw $s1, 0x2C($sp) |
paul@68 | 48 | sw $s0, 0x30($sp) |
paul@68 | 49 | sw $t7, 0x34($sp) |
paul@68 | 50 | sw $t6, 0x38($sp) |
paul@68 | 51 | sw $t5, 0x3C($sp) |
paul@68 | 52 | sw $t4, 0x40($sp) |
paul@68 | 53 | sw $t3, 0x44($sp) |
paul@68 | 54 | sw $t2, 0x48($sp) |
paul@68 | 55 | sw $t1, 0x4C($sp) |
paul@68 | 56 | sw $t0, 0x50($sp) |
paul@68 | 57 | sw $a3, 0x54($sp) |
paul@68 | 58 | sw $a2, 0x58($sp) |
paul@68 | 59 | sw $a1, 0x5C($sp) |
paul@68 | 60 | sw $a0, 0x60($sp) |
paul@68 | 61 | sw $v1, 0x64($sp) |
paul@68 | 62 | sw $v0, 0x68($sp) |
paul@68 | 63 | sw $1, 0x6C($sp) |
paul@68 | 64 | mflo $k0 |
paul@68 | 65 | nop |
paul@68 | 66 | sw $k0, 0x70($sp) |
paul@68 | 67 | mfhi $k0 |
paul@68 | 68 | nop |
paul@68 | 69 | sw $k0, 0x74($sp) |
paul@68 | 70 | mfc0 $k0, C0_STATUS |
paul@68 | 71 | sll $zero, 1 |
paul@68 | 72 | sll $zero, 1 |
paul@68 | 73 | sll $zero, 1 |
paul@68 | 74 | sll $zero, 1 |
paul@68 | 75 | sw $k0, 0x78($sp) |
paul@68 | 76 | mfc0 $k0, C0_EPC |
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 $k0, 0x7C($sp) |
paul@68 | 82 | |
paul@68 | 83 | li $k1, M_CauseExcCode |
paul@68 | 84 | mfc0 $k0, C0_CAUSE |
paul@68 | 85 | and $k0, $k1 |
paul@68 | 86 | beq $zero, $k0, _int |
paul@68 | 87 | nop |
paul@68 | 88 | j _exception |
paul@68 | 89 | nop |
paul@68 | 90 | |
paul@68 | 91 | _int: |
paul@68 | 92 | /* Invoke the handler. */ |
paul@68 | 93 | |
paul@68 | 94 | jal irq_handle |
paul@68 | 95 | nop |
paul@68 | 96 | j _exception_return |
paul@69 | 97 | nop |
paul@68 | 98 | |
paul@68 | 99 | _exception: |
paul@68 | 100 | move $a0, $sp |
paul@68 | 101 | mfc0 $a1, C0_CAUSE |
paul@68 | 102 | sll $zero, 1 |
paul@68 | 103 | sll $zero, 1 |
paul@68 | 104 | sll $zero, 1 |
paul@68 | 105 | sll $zero, 1 |
paul@68 | 106 | mfc0 $a2, C0_EPC |
paul@68 | 107 | sll $zero, 1 |
paul@68 | 108 | sll $zero, 1 |
paul@68 | 109 | sll $zero, 1 |
paul@68 | 110 | sll $zero, 1 |
paul@68 | 111 | /* jal exception_handler */ |
paul@68 | 112 | j _exception_return |
paul@68 | 113 | nop |
paul@68 | 114 | |
paul@68 | 115 | _exception_return: |
paul@68 | 116 | lw $ra, 0($sp) |
paul@68 | 117 | lw $fp, 4($sp) |
paul@68 | 118 | lw $gp, 8($sp) |
paul@68 | 119 | lw $t9, 0xC($sp) |
paul@68 | 120 | lw $t8, 0x10($sp) |
paul@68 | 121 | lw $s7, 0x14($sp) |
paul@68 | 122 | lw $s6, 0x18($sp) |
paul@68 | 123 | lw $s5, 0x1C($sp) |
paul@68 | 124 | lw $s4, 0x20($sp) |
paul@68 | 125 | lw $s3, 0x24($sp) |
paul@68 | 126 | lw $s2, 0x28($sp) |
paul@68 | 127 | lw $s1, 0x2C($sp) |
paul@68 | 128 | lw $s0, 0x30($sp) |
paul@68 | 129 | lw $t7, 0x34($sp) |
paul@68 | 130 | lw $t6, 0x38($sp) |
paul@68 | 131 | lw $t5, 0x3C($sp) |
paul@68 | 132 | lw $t4, 0x40($sp) |
paul@68 | 133 | lw $t3, 0x44($sp) |
paul@68 | 134 | lw $t2, 0x48($sp) |
paul@68 | 135 | lw $t1, 0x4C($sp) |
paul@68 | 136 | lw $t0, 0x50($sp) |
paul@68 | 137 | lw $a3, 0x54($sp) |
paul@68 | 138 | lw $a2, 0x58($sp) |
paul@68 | 139 | lw $a1, 0x5C($sp) |
paul@68 | 140 | lw $a0, 0x60($sp) |
paul@68 | 141 | lw $v1, 0x64($sp) |
paul@68 | 142 | lw $v0, 0x68($sp) |
paul@68 | 143 | lw $1, 0x6C($sp) |
paul@68 | 144 | lw $k0, 0x70($sp) |
paul@68 | 145 | mtlo $k0 |
paul@68 | 146 | nop |
paul@68 | 147 | lw $k0, 0x74($sp) |
paul@68 | 148 | mthi $k0 |
paul@68 | 149 | nop |
paul@68 | 150 | lw $k0, 0x78($sp) |
paul@68 | 151 | mtc0 $k0, C0_STATUS |
paul@68 | 152 | nop |
paul@68 | 153 | sll $zero, 1 |
paul@68 | 154 | sll $zero, 1 |
paul@68 | 155 | sll $zero, 1 |
paul@68 | 156 | sll $zero, 1 |
paul@68 | 157 | lw $k0, 0x7C($sp) |
paul@68 | 158 | mtc0 $k0, C0_EPC |
paul@68 | 159 | nop |
paul@68 | 160 | sll $zero, 1 |
paul@68 | 161 | sll $zero, 1 |
paul@68 | 162 | sll $zero, 1 |
paul@68 | 163 | sll $zero, 1 |
paul@68 | 164 | addiu $sp, 0x80 |
paul@68 | 165 | eret |
paul@68 | 166 | nop |
paul@68 | 167 | |
paul@68 | 168 | .set reorder |
paul@68 | 169 | .set at |