source: mainline/arch/ia64/src/start.S@ a2a46ba

#
# 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

.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;;
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}

.global paging_start
paging_start:

        /*
         * Now we are paging.
         */

        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}
        {nop 0;;}

        # 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