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#
# Copyright (C) 2005 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.
#

#include <arch/register.h>
#include <arch/mm/page.h>
#include <arch/mm/asid.h>
#include <mm/asid.h>

#define RR_MASK (0xFFFFFFFF00000002)
#define RID_SHIFT 8
#define PS_SHIFT 2

#define KERNEL_TRANSLATION_I 0x0010000000000661
#define KERNEL_TRANSLATION_D 0x0010000000000661

.section K_TEXT_START, "ax"

.global kernel_image_start

stack0:
kernel_image_start:
    .auto

    # Fill TR.i and TR.d using Region Register #VRN_KERNEL

    movl r8=(VRN_KERNEL<<VRN_SHIFT)
    mov r9=rr[r8]
    movl r10=(RR_MASK)
    and r9=r10,r9
    movl r10=((RID_KERNEL<<RID_SHIFT)|(KERNEL_PAGE_WIDTH<<PS_SHIFT))
    or  r9=r10,r9
    mov rr[r8]=r9

    movl r8=(VRN_KERNEL<<VRN_SHIFT)
    mov cr.ifa=r8
    movl r10=(KERNEL_PAGE_WIDTH<<PS_SHIFT)
    mov cr.itir=r10
    movl r10=(KERNEL_TRANSLATION_I)
    itr.i itr[r0]=r10
    movl r10=(KERNEL_TRANSLATION_D)
    itr.d dtr[r0]=r10

    # initialize PSR
    mov psr.l = r0
    srlz.i
    srlz.d
    movl r10=(PSR_DT_MASK|PSR_RT_MASK|PSR_IT_MASK|PSR_IC_MASK)  /* Enable paging */
    mov r9=psr
    or r10=r10,r9
    mov cr.ipsr=r10
    mov cr.ifs=r0
    movl r8=paging_start
    mov cr.iip=r8
    srlz.d
    srlz.i

    .explicit
    /*
     * Return From Interupt is the only the way to fill upper half word of PSR.
     */
    rfi;;

.global paging_start
paging_start:

    /*
     * Now we are paging.
     */

    # switch to register bank 1
    bsw.1
    
    # initialize register stack
    mov ar.rsc = r0
    movl r8=(VRN_KERNEL<<VRN_SHIFT) ;;
    mov ar.bspstore = r8
    loadrs

    # initialize memory stack to some sane value
    movl r12 = stack0;;
    
    add r12 = - 16, r12 /* allocate a scratch area on the stack */

    # initialize gp (Global Pointer) register
    movl r1 = _hardcoded_load_address

    /*
     * Initialize hardcoded_* variables.
     */
    movl r14 = _hardcoded_ktext_size
    movl r15 = _hardcoded_kdata_size
    movl r16 = _hardcoded_load_address ;;
    addl r17 = @gprel(hardcoded_ktext_size), gp
    addl r18 = @gprel(hardcoded_kdata_size), gp
    addl r19 = @gprel(hardcoded_load_address), gp
    ;;
    st8 [r17] = r14
    st8 [r18] = r15
    st8 [r19] = r16

    movl r18=main_bsp ;;
    mov b1=r18 ;;
    br.call.sptk.many b0=b1

0:
    br 0b