HelenOS sources

root/kernel/arch/arm32/src/start.S

#
# Copyright (c) 2007 Michal Kebrt
# 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 <abi/asmtool.h>
#include <arch/asm/boot.h>

.text

SYMBOL(kernel_image_start)
        # initialize Stack pointer for exception modes
        mrs r4, cpsr
        bic r4, r4, #0x1f

        #FIQ Mode
        orr r3, r4, #0x11
        msr cpsr_c, r3
        ldr sp, =exc_stack

        #IRQ Mode
        orr r3, r4, #0x12
        msr cpsr_c, r3
        ldr sp, =exc_stack

        #ABORT Mode
        orr r3, r4, #0x17
        msr cpsr_c, r3
        ldr sp, =exc_stack

        #UNDEFINED Mode
        orr r3, r4, #0x1b
        msr cpsr_c, r3
        ldr sp, =exc_stack

        # switch to supervisor mode
        orr r3, r4, #0x13
        msr cpsr_c, r3

        ldr sp, =temp_stack

        bl arm32_pre_main

        #
        # Create the first stack frame.
        #
        mov fp, #0
        mov ip, sp
        push {fp, ip, lr, pc}
        sub fp, ip, #4

        bl main_bsp

        .space TEMP_STACK_SIZE
temp_stack:

        .space 1024
SYMBOL(exc_stack)

SYMBOL(supervisor_sp)
        .space 4