/*****************************************************************************************
 Copyright (c) 2002-2004 The UbixOS Project
 All rights reserved.

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 permitted provided that the following conditions are met:

 Redistributions of source code must retain the above copyright notice, this list of
 conditions, the following disclaimer and the list of authors.  Redistributions in binary
 form must reproduce the above copyright notice, this list of conditions, the following
 disclaimer and the list of authors in the documentation and/or other materials provided
 with the distribution. Neither the name of the UbixOS Project nor the names of its
 contributors may be used to endorse or promote products derived from this software
 without specific prior written permission.

 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 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
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 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 $Id: page_fault.S 205 2016-01-23 19:18:59Z reddawg $

 *****************************************************************************************/

/*
 Page fault wrapper this will aquire some values we need for later use
 */

.globl _vmm_pageFault2
.text
.code32
_vmm_pageFault2:
xchgl %eax,(%esp) /* Save EAX                                         */
movl 4(%esp),%eax /* Move EIP into EAX to use later                   */
pushl %ebx /* Save EBX                                         */
movl 20(%esp),%ebx /* Save ESP for ring 3 to use later                 */
pushl %ecx /* Save ECX,EDX                                     */
pushl %edx
push %ebx /* Push ESP                                         */
push %eax /* Push EIP                                         */
movl %cr2,%eax /* Push the faulted address                         */
pushl %eax
sti /* Turn interrupts back on we are now entrant safe  */
call vmm_pageFault /* Call our page fault handler                      */
addl $0xC,%esp /* Adjust the stack to compensate for pushed values */
popl %edx /* Restore EAX,EBX,ECX,EDX                          */
popl %ecx
popl %ebx
popl %eax
iret /* Return from the interrupt                        */

.globl _vmm_pageFault
.text
.code32

_BALLS:
_B3:
nop

_ast:

_astRet:

_vmm_pageFault:
pushl $0xC
pushal
push %ds
push %es
push %fs
push %gs
mov $0x10,%eax
mov %eax,%ds
mov %eax,%es
mov %eax,%fs
cld
push %esp
call trap
notyet:
pushl %eax
sti
call vmm_pageFault
/* call syscall */
add $0x4,%esp
cmpb $0x13,0x38(%esp)
je _BALLS
testl $0x2000,0x3c(%esp) /* Test If VM */
jz _notVM
jmp _isVM
_notVM:
testb $0x3,0x38(%esp) /* See If We're In User CS (GDT Entry 5) */
jz _popFS
cli
mov %fs:0x0,%eax
testl $0x10800,0x80(%eax) /* Document This */
je _popFS
sti
push %esp
call _ast
add $0x4,%esp
jmp _astRet
_isVM:
hlt

_popFS:
pop %gs
pop %fs
pop %es
pop %ds
popa
add $0x8,%esp
iret

/***
 END
 ***/