Subversion Repositories HelenOS-historic

#
# Copyright (C) 2001-2004 Jakub Jermar
# 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.
#

#
# Init code for application processors.
#

.text

#ifdef __SMP__

.global ap_boot

KTEXT=8
KDATA=16

# This piece of code is real-mode and is meant to be alligned at 4K boundary.
# The requirement for such an alignment comes from MP Specification's STARTUP IPI
# requirements.

.align 4096
ap_boot:
.code16
    cli

    xorw %ax,%ax
    movw %ax,%ds

    lgdt gdtr
    movl %cr0,%eax
    orl $1,%eax
    movl %eax,%cr0
    ljmp $KTEXT,$jump_to_kernel

# this is where the AP enters the kernel space
jump_to_kernel:
.code32
    movw $KDATA,%ax
    movw %ax,%ds
    movw %ax,%es
    movw %ax,%ss
    movl $ctx,%eax
    movl (%eax),%esp

    lidt idtr

    ljmp $KTEXT,$main_ap

#endif /* __SMP__ */