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#

# 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.

#

.text

.global context_save

.global context_restore

#

# save context of this CPU

context_save:

	push %ebx

	movl 4(%esp),%eax	# the caller's return %eip

	movl 8(%esp),%ebx	# address of the kernel_context variable to save context to

        movl %eax,4(%ebx)	# %eip -> ctx->pc

	movl %esp,(%ebx)	# %esp -> ctx->sp

	movl %ebx,%eax

	pop %ebx

	movl %ebx,8(%eax)

	movl %ecx,12(%eax)

	movl %edx,16(%eax)

	movl %esi,20(%eax)

	movl %edi,24(%eax)

	movl %ebp,28(%eax)    

	xorl %eax,%eax		# context_save returns 1

	incl %eax

	ret

#

# restore saved context on this CPU

context_restore:

	movl 4(%esp),%eax	# address of the kernel_context variable to restore context from

	movl (%eax),%esp	# ctx->sp -> %esp

	addl $4,%esp		# this is for the pop we don't do

	movl 8(%eax),%ebx

	movl 12(%eax),%ecx

	movl 16(%eax),%edx

	movl 20(%eax),%esi

	movl 24(%eax),%edi

	movl 28(%eax),%ebp

	movl 4(%eax),%eax

	movl %eax,(%esp)	# ctx->pc -> saver's return %eip

        xorl %eax,%eax		# context_restore returns 0

	ret

.global fpu_context_save

fpu_context_save:

    ret

.global fpu_context_restore

fpu_context_restore:

    ret

.global fpu_lazy_context_save

    mov 4(%esp),%eax;

    fxsave (%eax)

    xor %eax,%eax;

    ret;

.global fpu_lazy_context_restore

    mov 4(%esp),%eax;

    fxrstor (%eax)

    xor %eax,%eax;

    ret;