source: mainline/boot/arch/mips32/src/asm.S@ 7cedc46a

#
# Copyright (c) 2006 Martin Decky
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#
# - Redistributions of source code must retain the above copyright
#   notice, this list of conditions and the following disclaimer.
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
# - The name of the author may not be used to endorse or promote products
#   derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

#include <arch/arch.h>
#include <arch/regname.h>

.set noat
.set noreorder
.set nomacro

.global start
.global halt
.global jump_to_kernel

.section BOOTSTRAP

start:
        /*
         * Setup the CP0 configuration
         *  - Disable 64-bit kernel addressing mode
         *  - DIsable 64-bit supervisor adressing mode
         *  - Disable 64-bit user addressing mode
         */
        mfc0 $a0, $status
        la $a1, 0xffffff1f
        and $a0, $a1, $a0
        mtc0 $a0, $status
        
        /*
         * Setup CPU map (on msim this code
         * is executed in parallel on all CPUs,
         * but it not an issue).
         */
        la $a0, PA2KA(CPUMAP_OFFSET)
        
        sw $zero, 0($a0)
        sw $zero, 4($a0)
        sw $zero, 8($a0)
        sw $zero, 12($a0)
        
        sw $zero, 16($a0)
        sw $zero, 20($a0)
        sw $zero, 24($a0)
        sw $zero, 28($a0)
        
        sw $zero, 32($a0)
        sw $zero, 36($a0)
        sw $zero, 40($a0)
        sw $zero, 44($a0)
        
        sw $zero, 48($a0)
        sw $zero, 52($a0)
        sw $zero, 56($a0)
        sw $zero, 60($a0)
        
        sw $zero, 64($a0)
        sw $zero, 68($a0)
        sw $zero, 72($a0)
        sw $zero, 76($a0)
        
        sw $zero, 80($a0)
        sw $zero, 84($a0)
        sw $zero, 88($a0)
        sw $zero, 92($a0)
        
        sw $zero, 96($a0)
        sw $zero, 100($a0)
        sw $zero, 104($a0)
        sw $zero, 108($a0)
        
        sw $zero, 112($a0)
        sw $zero, 116($a0)
        sw $zero, 120($a0)
        sw $zero, 124($a0)
        
        lui $a1, 1
        
#ifdef MACHINE_msim
        
        /* Read dorder value */
        la $k0, MSIM_DORDER_ADDRESS
        lw $k1, ($k0)
        
        /*
         * If we are not running on BSP
         * then end in an infinite loop.
         */
        beq $k1, $zero, bsp
        nop
        
        /* Record CPU presence */
        sll $a2, $k1, 2
        addu $a2, $a2, $a0
        sw $a1, ($a2)
        
        loop:
                j loop
                nop
        
#endif
        
        bsp:
                /* Record CPU presence */
                sw $a1, ($a0)
                
                /* Setup initial stack */
                la $sp, PA2KA(STACK_OFFSET)
                
                j bootstrap
                nop

.text

halt:
        j halt
        nop

jump_to_kernel:
        /*
         * TODO:
         *
         * Make sure that the I-cache, D-cache and memory are mutually
         * coherent before passing control to the copied code.
         */
        j $a0
        nop