vm86bios.s revision 47081
134840Sjlemon/*- 234840Sjlemon * Copyright (c) 1998 Jonathan Lemon 334840Sjlemon * All rights reserved. 434840Sjlemon * 534840Sjlemon * Redistribution and use in source and binary forms, with or without 634840Sjlemon * modification, are permitted provided that the following conditions 734840Sjlemon * are met: 834840Sjlemon * 1. Redistributions of source code must retain the above copyright 934840Sjlemon * notice, this list of conditions and the following disclaimer. 1034840Sjlemon * 2. Redistributions in binary form must reproduce the above copyright 1134840Sjlemon * notice, this list of conditions and the following disclaimer in the 1234840Sjlemon * documentation and/or other materials provided with the distribution. 1334840Sjlemon * 1434840Sjlemon * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1534840Sjlemon * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1634840Sjlemon * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1734840Sjlemon * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1834840Sjlemon * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1934840Sjlemon * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2034840Sjlemon * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2134840Sjlemon * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2234840Sjlemon * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2334840Sjlemon * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2434840Sjlemon * SUCH DAMAGE. 2534840Sjlemon * 2647081Sluoqi * $Id: vm86bios.s,v 1.12 1999/05/12 21:30:51 luoqi Exp $ 2734840Sjlemon */ 2834840Sjlemon 2934840Sjlemon#include "opt_vm86.h" 3034840Sjlemon 3134840Sjlemon#include <machine/asmacros.h> /* miscellaneous asm macros */ 3234840Sjlemon#include <machine/trap.h> 3334840Sjlemon 3434840Sjlemon#include "assym.s" 3534840Sjlemon 3637889Sjlemon#define SCR_NEWPTD PCB_ESI /* readability macros */ 3737889Sjlemon#define SCR_VMFRAME PCB_EBP /* see vm86.c for explanation */ 3837889Sjlemon#define SCR_STACK PCB_ESP 3937889Sjlemon#define SCR_PGTABLE PCB_EBX 4037889Sjlemon#define SCR_ARGFRAME PCB_EIP 4146129Sluoqi#define SCR_TSS0 PCB_SPARE 4246129Sluoqi#define SCR_TSS1 (PCB_SPARE+4) 4337889Sjlemon 4434840Sjlemon .data 4534840Sjlemon ALIGN_DATA 4634840Sjlemon 4734840Sjlemon .globl _in_vm86call, _vm86pcb 4834840Sjlemon 4934840Sjlemon_in_vm86call: .long 0 5034840Sjlemon_vm86pcb: .long 0 5134840Sjlemon 5234840Sjlemon .text 5334840Sjlemon 5434840Sjlemon/* 5534840Sjlemon * vm86_bioscall(struct trapframe_vm86 *vm86) 5634840Sjlemon */ 5734840SjlemonENTRY(vm86_bioscall) 5837889Sjlemon movl _vm86pcb,%edx /* scratch data area */ 5934840Sjlemon movl 4(%esp),%eax 6037889Sjlemon movl %eax,SCR_ARGFRAME(%edx) /* save argument pointer */ 6134840Sjlemon pushl %ebx 6234840Sjlemon pushl %ebp 6334840Sjlemon pushl %esi 6434840Sjlemon pushl %edi 6534840Sjlemon pushl %gs 6634840Sjlemon 6734840Sjlemon#ifdef SMP 6834840Sjlemon pushl %edx 6934840Sjlemon ALIGN_LOCK /* Get global lock */ 7034840Sjlemon popl %edx 7134840Sjlemon#endif 7234840Sjlemon 7334840Sjlemon#if NNPX > 0 7439775Sjlemon movl _curproc,%ecx 7534840Sjlemon cmpl %ecx,_npxproc /* do we need to save fp? */ 7634840Sjlemon jne 1f 7739872Sjlemon testl %ecx,%ecx 7839872Sjlemon je 1f /* no curproc/npxproc */ 7939046Syokota pushl %edx 8034840Sjlemon movl P_ADDR(%ecx),%ecx 8134840Sjlemon addl $PCB_SAVEFPU,%ecx 8239046Syokota pushl %ecx 8334840Sjlemon call _npxsave 8439046Syokota popl %ecx 8534840Sjlemon popl %edx /* recover our pcb */ 8634840Sjlemon#endif 8734840Sjlemon 8834840Sjlemon1: 8937889Sjlemon movl SCR_VMFRAME(%edx),%ebx /* target frame location */ 9034840Sjlemon movl %ebx,%edi /* destination */ 9137889Sjlemon movl SCR_ARGFRAME(%edx),%esi /* source (set on entry) */ 9247080Sluoqi movl $VM86_FRAMESIZE/4,%ecx /* sizeof(struct vm86frame)/4 */ 9334840Sjlemon cld 9434840Sjlemon rep 9534840Sjlemon movsl /* copy frame to new stack */ 9634840Sjlemon 9734840Sjlemon movl _curpcb,%eax 9834840Sjlemon pushl %eax /* save curpcb */ 9934840Sjlemon movl %edx,_curpcb /* set curpcb to vm86pcb */ 10034840Sjlemon 10147081Sluoqi movl _tss_gdt,%ebx /* entry in GDT */ 10234840Sjlemon movl 0(%ebx),%eax 10337889Sjlemon movl %eax,SCR_TSS0(%edx) /* save first word */ 10434840Sjlemon movl 4(%ebx),%eax 10534840Sjlemon andl $~0x200, %eax /* flip 386BSY -> 386TSS */ 10637889Sjlemon movl %eax,SCR_TSS1(%edx) /* save second word */ 10734840Sjlemon 10834840Sjlemon movl PCB_EXT(%edx),%edi /* vm86 tssd entry */ 10934840Sjlemon movl 0(%edi),%eax 11034840Sjlemon movl %eax,0(%ebx) 11134840Sjlemon movl 4(%edi),%eax 11234840Sjlemon movl %eax,4(%ebx) 11347081Sluoqi movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 11434840Sjlemon ltr %si 11534840Sjlemon 11634840Sjlemon movl %cr3,%eax 11734840Sjlemon pushl %eax /* save address space */ 11834840Sjlemon movl _IdlePTD,%ecx 11934840Sjlemon movl %ecx,%ebx 12034840Sjlemon addl $KERNBASE,%ebx /* va of Idle PTD */ 12134840Sjlemon movl 0(%ebx),%eax 12234840Sjlemon pushl %eax /* old ptde != 0 when booting */ 12334840Sjlemon pushl %ebx /* keep for reuse */ 12434840Sjlemon 12537889Sjlemon movl %esp,SCR_STACK(%edx) /* save current stack location */ 12634840Sjlemon 12737889Sjlemon movl SCR_NEWPTD(%edx),%eax /* mapping for vm86 page table */ 12834840Sjlemon movl %eax,0(%ebx) /* ... install as PTD entry 0 */ 12934840Sjlemon 13034840Sjlemon movl %ecx,%cr3 /* new page tables */ 13137889Sjlemon movl SCR_VMFRAME(%edx),%esp /* switch to new stack */ 13234840Sjlemon 13334840Sjlemon call _vm86_prepcall /* finish setup */ 13434840Sjlemon 13534840Sjlemon movl $1,_in_vm86call /* set flag for trap() */ 13634840Sjlemon 13734840Sjlemon /* 13834840Sjlemon * Return via _doreti 13934840Sjlemon */ 14034840Sjlemon#ifdef SMP 14134840Sjlemon ECPL_LOCK 14234840Sjlemon#ifdef CPL_AND_CML 14334840Sjlemon#error Not ready for CPL_AND_CML 14434840Sjlemon#endif 14534840Sjlemon pushl _cpl /* cpl to restore */ 14634840Sjlemon ECPL_UNLOCK 14734840Sjlemon#else 14834840Sjlemon pushl _cpl /* cpl to restore */ 14934840Sjlemon#endif 15034840Sjlemon subl $4,%esp /* dummy unit */ 15134840Sjlemon MPLOCKED incb _intr_nesting_level 15234840Sjlemon MEXITCOUNT 15334840Sjlemon jmp _doreti 15434840Sjlemon 15534840Sjlemon 15634840Sjlemon/* 15734840Sjlemon * vm86_biosret(struct trapframe_vm86 *vm86) 15834840Sjlemon */ 15934840SjlemonENTRY(vm86_biosret) 16034840Sjlemon movl _vm86pcb,%edx /* data area */ 16134840Sjlemon 16234840Sjlemon movl 4(%esp),%esi /* source */ 16337889Sjlemon movl SCR_ARGFRAME(%edx),%edi /* destination */ 16447080Sluoqi movl $VM86_FRAMESIZE/4,%ecx /* size */ 16534840Sjlemon cld 16634840Sjlemon rep 16734840Sjlemon movsl /* copy frame to original frame */ 16834840Sjlemon 16937889Sjlemon movl SCR_STACK(%edx),%esp /* back to old stack */ 17034840Sjlemon popl %ebx /* saved va of Idle PTD */ 17134840Sjlemon popl %eax 17234840Sjlemon movl %eax,0(%ebx) /* restore old pte */ 17334840Sjlemon popl %eax 17434840Sjlemon movl %eax,%cr3 /* install old page table */ 17534840Sjlemon 17634840Sjlemon movl $0,_in_vm86call /* reset trapflag */ 17734840Sjlemon 17847081Sluoqi movl _tss_gdt,%ebx /* entry in GDT */ 17937889Sjlemon movl SCR_TSS0(%edx),%eax 18034840Sjlemon movl %eax,0(%ebx) /* restore first word */ 18137889Sjlemon movl SCR_TSS1(%edx),%eax 18234840Sjlemon movl %eax,4(%ebx) /* restore second word */ 18347081Sluoqi movl $GPROC0_SEL*8,%esi /* GSEL(entry, SEL_KPL) */ 18434840Sjlemon ltr %si 18534840Sjlemon 18634840Sjlemon popl _curpcb /* restore curpcb/curproc */ 18737889Sjlemon movl SCR_ARGFRAME(%edx),%edx /* original stack frame */ 18834840Sjlemon movl TF_TRAPNO(%edx),%eax /* return (trapno) */ 18934840Sjlemon 19034840Sjlemon popl %gs 19134840Sjlemon popl %edi 19234840Sjlemon popl %esi 19334840Sjlemon popl %ebp 19434840Sjlemon popl %ebx 19534840Sjlemon ret /* back to our normal program */ 196