/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * $Id$ * * Copyright (C) 2008 by Maurus Cuelenaere * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ /* * init.S * * Initialization code for JzRISC. * * Author: Seeger Chin * e-mail: seeger.chin@gmail.com * * Copyright (C) 2006 Ingenic Semiconductor Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * */ #include "config.h" #include "mips.h" .text .set mips32 .extern system_main .extern main .global _start .section .init.text .set noreorder .set noat #ifdef BOOTLOADER /* These will get filled in scramble */ .word 0 /* Unknown */ .word 0 /* Filesize */ /* Relocate bootloader */ la t0, (_loadaddress-0x400000) la t1, _loadaddress la t2, _bootend _relocate_loop: lw t3, 0(t0) sw t3, 0(t1) addiu t1, 4 bne t1, t2, _relocate_loop addiu t0, 4 #endif _start: la ra, _start /* ---------------------------------------------------- Init CP0 registers. ---------------------------------------------------- */ mtc0 zero, C0_WATCHLO mtc0 zero, C0_WATCHHI li t0, (M_StatusBEV | M_StatusIM7 | M_StatusIM6 \ | M_StatusIM5 | M_StatusIM4 | M_StatusIM3 \ | M_StatusIM2 | M_StatusERL) /* BEV = Enable Boot Exception Vectors IMx = Interrupt mask ERL = Denotes error level */ mtc0 t0, C0_STATUS li t0, M_CauseIV mtc0 t0, C0_CAUSE /* ---------------------------------------------------- Init caches, assumes a 4way*128set*32byte I/D cache ---------------------------------------------------- */ li t0, 3 # enable cache for kseg0 accesses mtc0 t0, C0_CONFIG # CONFIG reg la t0, 0x80000000 # an idx op should use an unmappable address ori t1, t0, 0x4000 # 16kB cache mtc0 zero, C0_TAGLO # TAGLO reg mtc0 zero, C0_TAGHI # TAGHI reg _init_cache_loop: cache 0x8, 0(t0) # index store icache tag cache 0x9, 0(t0) # index store dcache tag bne t0, t1, _init_cache_loop addiu t0, t0, 0x20 # 32 bytes per cache line nop /* ---------------------------------------------------- Invalidate BTB ---------------------------------------------------- */ mfc0 t0, C0_CONFIG nop ori t0, 2 mtc0 t0, C0_CONFIG nop /* ---------------------------------------------------- Clear BSS section ---------------------------------------------------- */ la t0, _edata la t1, _end _init_bss_loop: sw zero, 0(t0) bne t0, t1, _init_bss_loop addiu t0, 4 /* ---------------------------------------------------- Clear IBSS section ---------------------------------------------------- */ la t0, _iedata la t1, _iend _init_ibss_loop: sw zero, 0(t0) bne t0, t1, _init_ibss_loop addiu t0, 4 /* ---------------------------------------------------- Copy IRAM section ---------------------------------------------------- */ la t0, _iramcopy la t1, _iramstart la t2, _iramend _init_iram_loop: lw t3, 0(t0) sw t3, 0(t1) addiu t1, 4 bne t1, t2, _init_iram_loop addiu t0, 4 /* ---------------------------------------------------- Setup stack ---------------------------------------------------- */ la sp, stackend la t0, stackbegin li t1, 0xDEADBEEF _init_stack_loop: sw t1, 0(t0) bne t0, sp, _init_stack_loop addiu t0, t0, 4 /* ---------------------------------------------------- Jump to C code ---------------------------------------------------- */ la t0, system_main /* Init clocks etc first */ jalr t0 nop la t0, main jr t0 nop /* * 0x0 - Simple TLB refill handler * 0x100 - Cache error handler * 0x180 - Exception/Interrupt handler * 0x200 - Special Exception Interrupt handler (when IV is set in CP0_CAUSE) */ .section .vectors.1, "ax", %progbits la k0, tlb_refill_handler jr k0 nop .section .vectors.2, "ax", %progbits la k0, real_exception_handler jr k0 nop .section .vectors.3, "ax", %progbits la k0, real_exception_handler jr k0 nop .section .vectors.4, "ax", %progbits la k0, real_exception_handler jr k0 nop .section .vectors, "ax", %progbits real_exception_handler: addiu sp, -0x80 sw ra, 0(sp) sw fp, 4(sp) sw gp, 8(sp) sw t9, 0xC(sp) sw t8, 0x10(sp) sw s7, 0x14(sp) sw s6, 0x18(sp) sw s5, 0x1C(sp) sw s4, 0x20(sp) sw s3, 0x24(sp) sw s2, 0x28(sp) sw s1, 0x2C(sp) sw s0, 0x30(sp) sw t7, 0x34(sp) sw t6, 0x38(sp) sw t5, 0x3C(sp) sw t4, 0x40(sp) sw t3, 0x44(sp) sw t2, 0x48(sp) sw t1, 0x4C(sp) sw t0, 0x50(sp) sw a3, 0x54(sp) sw a2, 0x58(sp) sw a1, 0x5C(sp) sw a0, 0x60(sp) sw v1, 0x64(sp) sw v0, 0x68(sp) sw $1, 0x6C(sp) mflo k0 nop sw k0, 0x70(sp) mfhi k0 nop sw k0, 0x74(sp) mfc0 k0, C0_STATUS # Status register sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 sw k0, 0x78(sp) mfc0 k0, C0_EPC # Exception Program Counter sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 sw k0, 0x7C(sp) li k1, M_CauseExcCode mfc0 k0, C0_CAUSE # C0_CAUSE of last exception and k0, k1 beq zero, k0, _int nop j _exception nop _int: jal intr_handler nop lw ra, 0(sp) lw fp, 4(sp) sw gp, 8(sp) lw t9, 0xC(sp) lw t8, 0x10(sp) lw s7, 0x14(sp) lw s6, 0x18(sp) lw s5, 0x1C(sp) lw s4, 0x20(sp) lw s3, 0x24(sp) lw s2, 0x28(sp) lw s1, 0x2C(sp) lw s0, 0x30(sp) lw t7, 0x34(sp) lw t6, 0x38(sp) lw t5, 0x3C(sp) lw t4, 0x40(sp) lw t3, 0x44(sp) lw t2, 0x48(sp) lw t1, 0x4C(sp) lw t0, 0x50(sp) lw a3, 0x54(sp) lw a2, 0x58(sp) lw a1, 0x5C(sp) lw a0, 0x60(sp) lw v1, 0x64(sp) lw v0, 0x68(sp) lw $1, 0x6C(sp) lw k0, 0x70(sp) mtlo k0 nop lw k0, 0x74(sp) mthi k0 nop lw k0, 0x78(sp) nop mtc0 k0, C0_STATUS # Status register sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 lw k0, 0x7C(sp) nop mtc0 k0, C0_EPC # Exception Program Counter sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 addiu sp, 0x80 eret # Exception Return nop _exception: add a0, sp, $0 mfc0 a1, C0_CAUSE # C0_CAUSE of last exception sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 mfc0 a2, C0_EPC # Exception Program Counter sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 jal exception_handler nop lw ra, 0(sp) lw fp, 4(sp) sw gp, 8(sp) lw t9, 0xC(sp) lw t8, 0x10(sp) lw s7, 0x14(sp) lw s6, 0x18(sp) lw s5, 0x1C(sp) lw s4, 0x20(sp) lw s3, 0x24(sp) lw s2, 0x28(sp) lw s1, 0x2C(sp) lw s0, 0x30(sp) lw t7, 0x34(sp) lw t6, 0x38(sp) lw t5, 0x3C(sp) lw t4, 0x40(sp) lw t3, 0x44(sp) lw t2, 0x48(sp) lw t1, 0x4C(sp) lw t0, 0x50(sp) lw a3, 0x54(sp) lw a2, 0x58(sp) lw a1, 0x5C(sp) lw a0, 0x60(sp) lw v1, 0x64(sp) lw v0, 0x68(sp) lw $1, 0x6C(sp) lw k0, 0x70(sp) mtlo k0 nop lw k0, 0x74(sp) mthi k0 nop lw k0, 0x78(sp) nop mtc0 k0, C0_STATUS # Status register sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 lw k0, 0x7C(sp) nop mtc0 k0, C0_EPC # Exception Program Counter sll zero, 1 sll zero, 1 sll zero, 1 sll zero, 1 addiu sp, 0x80 eret # Exception Return nop .set reorder