177 lines
4.8 KiB
ArmAsm
177 lines
4.8 KiB
ArmAsm
/*-
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* Copyright (c) 1998 Jonathan Lemon
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#include <machine/asmacros.h> /* miscellaneous asm macros */
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#include <machine/trap.h>
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#include "assym.s"
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#define SCR_NEWPTD PCB_ESI /* readability macros */
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#define SCR_VMFRAME PCB_EBP /* see vm86.c for explanation */
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#define SCR_STACK PCB_ESP
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#define SCR_PGTABLE PCB_EBX
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#define SCR_ARGFRAME PCB_EIP
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#define SCR_TSS0 PCB_SPARE
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#define SCR_TSS1 (PCB_SPARE+4)
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.data
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ALIGN_DATA
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.globl _in_vm86call, _vm86pcb
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_in_vm86call: .long 0
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_vm86pcb: .long 0
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.text
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/*
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* vm86_bioscall(struct trapframe_vm86 *vm86)
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*/
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ENTRY(vm86_bioscall)
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movl _vm86pcb,%edx /* scratch data area */
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movl 4(%esp),%eax
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movl %eax,SCR_ARGFRAME(%edx) /* save argument pointer */
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pushl %ebx
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pushl %ebp
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pushl %esi
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pushl %edi
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pushl %gs
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#if NNPX > 0
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movl _curproc,%ecx
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cmpl %ecx,_npxproc /* do we need to save fp? */
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jne 1f
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testl %ecx,%ecx
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je 1f /* no curproc/npxproc */
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pushl %edx
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movl P_ADDR(%ecx),%ecx
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addl $PCB_SAVEFPU,%ecx
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pushl %ecx
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call _npxsave
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popl %ecx
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popl %edx /* recover our pcb */
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#endif
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1:
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movl SCR_VMFRAME(%edx),%ebx /* target frame location */
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movl %ebx,%edi /* destination */
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movl SCR_ARGFRAME(%edx),%esi /* source (set on entry) */
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movl $VM86_FRAMESIZE/4,%ecx /* sizeof(struct vm86frame)/4 */
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cld
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rep
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movsl /* copy frame to new stack */
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movl _curpcb,%eax
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pushl %eax /* save curpcb */
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movl %edx,_curpcb /* set curpcb to vm86pcb */
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movl _tss_gdt,%ebx /* entry in GDT */
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movl 0(%ebx),%eax
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movl %eax,SCR_TSS0(%edx) /* save first word */
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movl 4(%ebx),%eax
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andl $~0x200, %eax /* flip 386BSY -> 386TSS */
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movl %eax,SCR_TSS1(%edx) /* save second word */
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movl PCB_EXT(%edx),%edi /* vm86 tssd entry */
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movl 0(%edi),%eax
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movl %eax,0(%ebx)
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movl 4(%edi),%eax
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movl %eax,4(%ebx)
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movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */
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ltr %si
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movl %cr3,%eax
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pushl %eax /* save address space */
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movl _IdlePTD,%ecx
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movl %ecx,%ebx
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addl $KERNBASE,%ebx /* va of Idle PTD */
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movl 0(%ebx),%eax
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pushl %eax /* old ptde != 0 when booting */
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pushl %ebx /* keep for reuse */
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movl %esp,SCR_STACK(%edx) /* save current stack location */
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movl SCR_NEWPTD(%edx),%eax /* mapping for vm86 page table */
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movl %eax,0(%ebx) /* ... install as PTD entry 0 */
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movl %ecx,%cr3 /* new page tables */
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movl SCR_VMFRAME(%edx),%esp /* switch to new stack */
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call _vm86_prepcall /* finish setup */
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movl $1,_in_vm86call /* set flag for trap() */
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/*
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* Return via _doreti
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*/
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incb _intr_nesting_level
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MEXITCOUNT
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jmp _doreti
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/*
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* vm86_biosret(struct trapframe_vm86 *vm86)
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*/
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ENTRY(vm86_biosret)
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movl _vm86pcb,%edx /* data area */
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movl 4(%esp),%esi /* source */
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movl SCR_ARGFRAME(%edx),%edi /* destination */
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movl $VM86_FRAMESIZE/4,%ecx /* size */
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cld
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rep
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movsl /* copy frame to original frame */
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movl SCR_STACK(%edx),%esp /* back to old stack */
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popl %ebx /* saved va of Idle PTD */
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popl %eax
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movl %eax,0(%ebx) /* restore old pte */
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popl %eax
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movl %eax,%cr3 /* install old page table */
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movl $0,_in_vm86call /* reset trapflag */
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movl _tss_gdt,%ebx /* entry in GDT */
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movl SCR_TSS0(%edx),%eax
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movl %eax,0(%ebx) /* restore first word */
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movl SCR_TSS1(%edx),%eax
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movl %eax,4(%ebx) /* restore second word */
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movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */
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ltr %si
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popl _curpcb /* restore curpcb/curproc */
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movl SCR_ARGFRAME(%edx),%edx /* original stack frame */
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movl TF_TRAPNO(%edx),%eax /* return (trapno) */
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popl %gs
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popl %edi
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popl %esi
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popl %ebp
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popl %ebx
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ret /* back to our normal program */
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