source: mainline/boot/arch/sparc64/loader/boot.S@ d6ff0fc5

#
# Copyright (c) 2006 Martin Decky
# Copyright (c) 2006 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 <stack.h>
#include <register.h>

#define INITIAL_STACK_SIZE  8192

#define NWINDOWS  8

.register %g2, #scratch
.register %g3, #scratch
.register %g6, #scratch
.register %g7, #scratch

.section BOOTSTRAP, "ax"

.global start
start:
        ba %xcc, 1f
        nop

/*
 * This header forces SILO to load the image at 0x4000.
 * More precisely, SILO will think this is an old version of Linux.
 */
        .ascii "HdrS"
        .word 0
        .half 0
        .half 0
        .half 0
        .half 0

.global silo_ramdisk_image
silo_ramdisk_image:
        .word 0

.global silo_ramdisk_size
silo_ramdisk_size:
        .word 0

.align 8
1:
        /*
         * Disable interrupts and disable address masking.
         */
        wrpr %g0, PSTATE_PRIV_BIT, %pstate
        
        wrpr %g0, NWINDOWS - 2, %cansave   ! set maximum saveable windows
        wrpr %g0, 0, %canrestore           ! get rid of windows we will never need again
        wrpr %g0, 0, %otherwin             ! make sure the window state is consistent
        wrpr %g0, NWINDOWS - 1, %cleanwin  ! prevent needless clean_window traps for kernel
        
        set initial_stack_top, %sp
        add %sp, -STACK_BIAS, %sp
        
        set ofw_cif, %l0
        
        call ofw_init   ! initialize OpenFirmware
        stx %o4, [%l0]
        
        ba %xcc, bootstrap
        nop

.align STACK_ALIGNMENT
initial_stack:
        .space INITIAL_STACK_SIZE

initial_stack_top:
        .space STACK_WINDOW_SAVE_AREA_SIZE