paul@0 | 1 | /* |
paul@63 | 2 | * Initialisation for the stage 1 payload with support for boot parameters. |
paul@0 | 3 | * |
paul@63 | 4 | * Copyright (C) 2009 Qi Hardware Inc. |
paul@59 | 5 | * Author: Wolfgang Spraul <wolfgang@sharism.cc> |
paul@0 | 6 | * |
paul@88 | 7 | * Copyright (C) 2015, 2016 Paul Boddie <paul@boddie.org.uk> |
paul@16 | 8 | * |
paul@63 | 9 | * This program is free software: you can redistribute it and/or modify |
paul@63 | 10 | * it under the terms of the GNU General Public License as published by |
paul@63 | 11 | * the Free Software Foundation, either version 3 of the License, or |
paul@63 | 12 | * (at your option) any later version. |
paul@0 | 13 | * |
paul@0 | 14 | * This program is distributed in the hope that it will be useful, |
paul@0 | 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
paul@0 | 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
paul@0 | 17 | * GNU General Public License for more details. |
paul@0 | 18 | * |
paul@0 | 19 | * You should have received a copy of the GNU General Public License |
paul@63 | 20 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
paul@0 | 21 | */ |
paul@0 | 22 | |
paul@194 | 23 | #include "memory.h" |
paul@194 | 24 | #include "mips.h" |
paul@194 | 25 | |
paul@70 | 26 | .text |
paul@70 | 27 | .extern c_main |
paul@70 | 28 | .globl _start |
paul@70 | 29 | .set noreorder |
paul@70 | 30 | |
paul@0 | 31 | _start: |
paul@70 | 32 | b real_start |
paul@0 | 33 | nop |
paul@88 | 34 | |
paul@88 | 35 | /* 8 words for firmware parameters (0x80002008), struct fw_args */ |
paul@88 | 36 | |
paul@70 | 37 | .word 0x0 |
paul@70 | 38 | .word 0x0 |
paul@70 | 39 | .word 0x0 |
paul@70 | 40 | .word 0x0 |
paul@70 | 41 | .word 0x0 |
paul@70 | 42 | .word 0x0 |
paul@70 | 43 | .word 0x0 |
paul@70 | 44 | .word 0x0 |
paul@88 | 45 | |
paul@59 | 46 | real_start: |
paul@88 | 47 | /* |
paul@88 | 48 | Reset various registers. Otherwise, interrupts do not apparently get |
paul@88 | 49 | re-enabled properly later when requested. |
paul@88 | 50 | */ |
paul@88 | 51 | |
paul@88 | 52 | li $t0, 0x0040fc04 /* BEV=1, interrupts enabled, ERL=1 */ |
paul@88 | 53 | mtc0 $t0, CP0_STATUS |
paul@88 | 54 | |
paul@88 | 55 | li $t0, 0x00800000 /* IV=1 */ |
paul@88 | 56 | mtc0 $t0, CP0_CAUSE |
paul@88 | 57 | |
paul@70 | 58 | /* Setup stack, jump to C code. */ |
paul@70 | 59 | |
paul@194 | 60 | la $sp, STAGE1_STACK |
paul@70 | 61 | j c_main |
paul@0 | 62 | nop |
paul@0 | 63 | |
paul@70 | 64 | .set reorder |